A rise in misleading marketing tactics and scams offering “free solar panels” has led many homeowners to believe they can receive a fully functional solar system for free. You may have seen such advertisements, but is there such a thing as free solar panels? Or is there a catch?

The good news is that there are plenty of unique financing structures available to get low or no cost solar panels installed. Read on to find out everything you need to know about obtaining free solar panels for your home.

Why go solar?

As the world seeks concrete ways to fight climate change, renewable energy sources have become more vital. Solar energy is becoming increasingly popular for residential and commercial buildings alike as a reliable source of renewable power.

Today’s solar panels are more efficient than ever before. Solar energy offers plenty of health and environmental benefits that go beyond fighting climate change, from preserving water to reducing the use of fossil fuels.

Not only are they great for the environment, but solar panels can also save their owners money on utility bills over time and even increase the value of a home. The average owner of a solar panel system could easily save an estimated $25,500 to $33,000 on electricity during the lifetime of the system.

However, if you’ve been shopping for the right solar panel system for your home or business, you’ve likely come across advertisements for free solar panels – these ads imply that a company will install a system for free. But is this really the case?

Is it really possible to get free solar panels?

To draw the attention of potential buyers, solar companies often market ‘free solar panels’. Before considering this offer, it’s important to understand what it really means.

The offer of free solar panels does not refer to a company installing solar panels at your house and never charging you for solar power again.

The cost to install a solar panel system can vary widely, depending on the size of the system: a small one can cost as low as $5,000, while large, high-end installations can cost upwards of $40,000. These costs also vary state to state in the U.S.

However, there are a variety of different ways to get solar panels installed at your home without having to pay this hefty cost upfront.

Free solar panels for home use

While it’s unlikely that solar panels will be gifted to you, there are a few ways to go solar with no upfront cost.

Solar panels are often referred to as free because a variety of different solar programs are zero down. This means that the solar panels are installed with no upfront cost, and then the owner pays for the use of the solar panels each month.

The reason this is so cost-effective (and ends up being free in the long run) is that your monthly payments are expected to be much lower than your previous utility bills when the grid supplied your electricity.

There are a couple of options for going solar without paying large sums of cash upfront. And, with the right program, your monthly repayments will be lower than your previous energy bills.

Solar leases and power purchase agreements

There are two primary agreements that homeowners can pursue to pay zero upfront costs on their solar panel systems. This can typically be achieved through Power Purchase Agreements (PPAs) and solar leases.

With a PPA, an energy company installs a solar system on your rooftop and sells you the energy that you use on a per-kWh price.

Solar leases are similar in that the energy company carries out the installation, but your fixed monthly fee is based on an estimate of the amount of power that you will use.

Are solar panels actually free when using a power purchase agreement?

PPAs, along with solar leases, have many zero down plans, meaning that you do not have to pay an upfront cost. All you need to pay is your monthly payments.

So how does it work?

Homeowners enter into a contract with a solar company and rent their solar panels for a period of around 15-25 years. After the panels have been installed on your roof, you then purchase electricity off the utility company.

Do solar leases actually save you money in the long run?

With solar leases and PPAs, there really is no upfront cost to install a solar panel system. In addition, the rate that you pay for energy is usually lower than the rate of typical energy bills. In this way, solar leases can bring in savings in the long run.

Leasees also do not have to pay to maintain or repair the panels, because they are technically owned by the solar company. It’s important to note that solar panels do not technically belong to the consumer in these agreements, but to the company leasing them out.

This situation presents some disadvantages, one of which being that you can not reap the benefits of owning your system such as tax rebates or incentives. These benefits go to the owners of the panels – the solar company.

A PPA or solar lease is usually easier to arrange, although they require a good credit score. It’s important to note, however, that not all states in the U.S. allow PPAs. There are currently fifteen states that allow PPAs.

How do solar loans differ?

Solar loans are considered to be a better financing option when it comes to maximizing the return on investment for a solar panel system. Solar loans allow you to borrow money from a lender to purchase your solar system, which you can repay over time with your energy savings.

Solar loans are generally preferred, because they grant ownership of the system. However, interest payments chip away at energy savings for approximately the first seven years until the loan is paid off.

The amount of time a solar loan takes to pay off ultimately depends on factors like the upfront cost, size, energy efficiency, and interest rates associated with your solar system. After the designated time period, owners get to keep all of their energy savings.

As the proud owner of your solar panel system, however, you can receive all of the tax benefits and incentives available from the government with a solar loan.

What federal and local solar incentives are available?

Once you are approved for a solar loan and own your system, there are several U.S. incentives available to you, depending on the state you live in.

The federal solar investment tax credit is available to all U.S. homeowners and is one of the best incentives to pursue. This credit provides solar panel owners with a 30% rebate on an entire system, which is beneficial if your tax bill is higher than the tax benefits that you could receive through this system.

Additional programs on the state level include Solar Renewable Energy Credits (SRECs) and performance-based incentives.

Eligible houses with solar systems that can produce more than one megawatt-hour (MWh) of electricity can claim SRECs. In certain states, SRECs are sold separately from the physical electricity that your solar panels produce. They are essentially vouchers that prove that the electricity from your solar panels is renewable.

Performance-based incentives are rewards given for producing a certain amount of solar energy. These incentives reward solar owners for choosing renewable energy.

It’s key to note that these federal and state-wide incentives can be combined, meaning you can benefit from both federal and state incentives to help offset the costs of going solar.

What kinds of solar loans are available?

There are a few different kinds of solar loans available to homeowners, depending on where you live.

Secured loans

Secured loans are often more affordable than unsecured loans because they have lower interest rates and are tax-deductible. However, this type of loan (for example, a home equity loan) does use your home as collateral, so you need to be sure that you can pay off the money.

An alternative to a home equity loan is an FHA Title 1 Secured Loan. This has a government guarantee, and instead of repossessing your home if you do not make the repayments, the outstanding amount is paid upon selling your house.

Unsecured loans

Unsecured loans may cost more, because there can be additional fees, the interest is higher, and you have no access to tax reductions. Similarly to credit cards and other loans, however, your home will not be used as collateral.

The penalty for non-payment is the negative impact on your credit card score.

PACE loans

A Property Assessed Clean Energy (PACE) loan is a straightforward financing option that is available to residents of California, Missouri, and Florida. PACE loans differ from solar loans as they tax assess your property.

Your payments for your solar system will show up along with your other property-related taxes on your tax assessment. Homeowners can benefit from this type of financing because, oftentimes, the first payment is not made for six months.

Your home is the only collateral on this type of loan, and it does not include any of your other assets. This means that they can be a little bit more expensive than other types of solar loans.

All in all, solar loans and leases are zero down. The monthly energy rates are lower than getting your electricity from the grid as usual. If you get a solar loan, once it’s paid off, thanks to the sun, your electricity really is free!

Community solar projects

Community solar is another great option for people who want to utilize solar energy with no upfront cost. Homeowners can simply sign a subscription agreement that says you will subscribe to a community solar project.

Then, the power of that facility will get credited to your electric bill as an offset. These programs are often a win-win, as they allow you to start saving money right away.

Free solar panels for seniors and low-income families

Solar panels are no longer just for the wealthy! Low-income families can also benefit from PPAs/solar leases and solar loans because there are no upfront costs, and savings are made every month compared to paying normal energy bills.

There are some specific low-income solar programs and initiatives happening across the United States which provide additional support for those on low incomes.

Similarly to low-income families, the best option for seniors wanting to go solar is to take out a solar loan or solar lease. Bear in mind that as a senior, if you are not paying tax, you may not receive the tax rebates that make solar loans such a great option.

Frequently asked questions about free solar panels

Let’s dive into the answers for a few of the most frequently asked questions on obtaining free solar panels.

How do solar panels work with my monthly electric bill?

Electricity generated using solar panels is fed back to the main grid. These systems will often use a net meter, which monitors the usage of electricity and keeps track of the units fed back into the grid.

How many solar panels would it take to power a house?

The average home in the U.S needs between 16 and 20 solar panels to cover its electric bills. Three main factors impact how many solar panels you need: your energy usage, the sunlight in your area, and the solar panels you choose.

Is the U.S. government giving away free solar panels?

We found no evidence of a federal program that provides free panels and incentive checks. Some homeowners may be eligible for tax credits related to solar panel installation, but that is not equivalent to a cash payment. We rate this claim False.

Can I sell my home in the middle of my solar lease or loan?

Sometimes, if you are mid-lease or loan, you can run into difficulty when putting your house up for sale.

If you financed your solar PV system with a secured loan, such as a home equity loan, you will need to pay off the rest of the balance before you sell, since your property was used as collateral for the loan.

If you financed your solar PV system with an unsecured loan (one that is not tied to your property), you can sell your home before paying off your loan — but you will still be responsible for paying off the loan.

Can free solar panels be installed on any home?

Not all homes are necessarily suitable for solar panels. If your roof is shaded all year round, you will not generate enough energy to power your home and you may need to purchase additional energy from the grid.

This means that solar power may not be the right option for your home, and you are better off trying to find a green energy provider if you want to power your home with more sustainable energy.

PVWatts is a useful tool that allows you to calculate how much energy your home could generate from solar power.

The final verdict on free solar panels

Although ‘free solar panels’ are not 100% free for most people, it is easier than ever to get solar panels today without paying a penny upfront. Solar leases/PPAs, solar loans, and community solar allow homeowners to install solar panels on their houses with zero down financing or no capital cost.

The bottom line is, although the description of free solar panels is a little misleading, if you take out a solar loan, solar panels are an investment that is sure to pay off over time.

Green Coast is a renewable energy and green living community focused on helping others live a better, more sustainable life.

With the world so eager to move from non-renewable energy sources to clean and green energy sources, anaerobic digestion has become one of the main areas that many countries are focusing.

Before we explore the various pros and cons of anaerobic digestors, let’s first define what it means and highlight a few facts about anaerobic digesters.

What is anaerobic digestion?

Anaerobic Digestion is the process of treating organic waste and involves a series of biological processes in which organic waste is broken down using microorganisms in the absence of oxygen. The end product of the process is Biogas, which is a methane-rich gas.

Once the biogas is cleaned, it is taken to a Combined Heat and Power (CHP) unit, where it is used to generate renewable energy.

The byproduct of the process is often used as fertilizer. The whole process of anaerobic bio-digestion takes place in a tank called the Anaerobic Biodigester.

A biodigester breaks down organic matter using bacteria and in the absence of oxygen to capture methane gas released by the bacteria in the process.  Methane, which is the main chemical in natural gas, is trapped and can then be burned for heating and electricity.

One of the commonly known types of the digester is called a “wet biodigester”. They are used on farms around the world to digest liquefied manure. The anaerobic digestor process is similar to compostable organic matter. The output is just gas that can be used for power.

Facts About Anaerobic Digestors

Many people use wet digesters to produce methane from manure which is then used to light their stoves and other appliances. Here are some few facts about anaerobic digesters

• The digester disinfects the feedstock/ waste which goes through it, as long as the temperature is maintained above a required level for a pre-defined period.
• One of the most impressive facts about anaerobic digestor is that it produces gas, liquid and fibrous fertilizers which are very beneficial.
• It reduces the odor levels if run efficiently.

Here are advantages and disadvantages of anaerobic digesters:

Pros of anaerobic digesters

Here are some of the advantages to anaerobic digesters.

1. Consistent supply of power

One of the major pros of anaerobic digesters is that it can offer a constant power supply to the universe. Since there is a continuous production of the waste materials used for the digestion process, anaerobic digestion can ensure a steady source of electricity generation.

For instance, every cow is estimated to produce 2kwh – 3kwh of electricity daily, which in turn can be sent to the electricity grid. Anaerobic digestion also generates renewable energy that is in the form of biogas. These biogases will likely qualify for Renewable Identification Numbers (RINs).

2. Renewable

Another advantage of anaerobic digestion is that it is a renewable source of energy since waste products from animals and humans are produced continually, and unlike non-renewable energy, it does not exploit natural resources.

The resources used provide a steady stream of inputs into the digesters.

See Related: 10 Biggest Pros and Cons of Nonrenewable Energy

3. Valuable by-products

Anaerobic digestion offers beneficial by-products. The by-products released in the process, which includes compost and fertilizer, can further be used in farms. The by-products can thus be used to create an additional stream of revenue. The liquid digestate that is produced in the process is a form of a fertilizer which is better in many ways than the standard chemical fertilizers.

Due to its high fiber content and the separated solids (ADS), it can also be sold as a horticultural potting mix or used as livestock bedding. The process produces both liquid and fibrous fertilizers which can be used in the farms or sold to create more income.

The effect of the compost is longer lasting than for untreated organic waste.

4. Odor reduction

Long-term exposure to pollution in the air can result in health complications and even death. The use of the waste products from the farms in the anaerobic digesters reduces the amount of odor that would otherwise be present if the wastes were left exposed to the environment. The anaerobic digestion process reduces smell to levels below unprocessed waste odor levels.

5. Improved water quality

Another advantage is that the process of anaerobic digestion helps to remove phosphorous and other metals from the waste products, which would otherwise contaminate water supplies if left unattended.

Passing the wastes through the digesters thus ensures an improved quality of water supplies.

6. Greenhouse gases reduction

A primary reason the world is moving from the use of the non-renewable sources of energy is to reduce the emission of greenhouse gases that destroy the ozone layer and expose the world to global warming. Anaerobic biodigester minimizes the amount of GHG gasses released by the farms into the environment by around 66%. The reduction of the gases earns the farm carbon credits which can be sold to generate extra revenue for the farm.

Businesses that are required to pay a carbon levy for their carbon dioxide emissions can also run their biogas plant to help them offset their levy costs against the carbon savings.

Passing the waste materials through a digester reduces pollution to the environment since the waste materials are used as feedstock for digesters. It is less likely to cause air pollution to the environment unlike spreading untreated organic waste in landfills.

Decarbonization is a huge component of the AD movement.

7. Reducing disease-causing pathogens in the manure

One of the most remarkable facts about anaerobic digesters is that the operating temperature of the anaerobic digester systems decreases the number of pathogens in the slurry which may cause diseases to the plants. It is also an advantage of anaerobic digesters.

See Related: Biofuel Pros and Cons Analysis

 Cons of anaerobic digesters

Here are some of the disadvantages to anaerobic digesters.

1. Expensive

Installation costs of the anaerobic digesters can be prohibitive since it requires some massive financing to set it up. The operating expenses and the maintenance cost are also costly which makes it difficult for farmers to acquire.

When anaerobic digestion is complete on a large commercial scale, it can require a high level of investment in large manure tanks and other process containers.

2. Limited to large farms only

The Anaerobic digesters are only economically feasible for larger farms. The EPA recommends that a farm should have at least 300 cows to be able to install and run the system. This limitation makes it difficult for smaller farmers with less number of animals to have these systems.

3. Time-consuming

Another con of anaerobic digesters is that the system operation and maintenance requirements are pretty much needed every day. It is estimated that it takes 30 to 60 minutes daily to ensure the efficient running of the system.

4. High land use

The more significant the amount of biogas you want to produce, the larger the farm you need for a large number of cows and large manure tanks. The residue from the process after manure has completed the digestion cycle, will also require a large chunk of land for storage.

5. Must have a reliable source and the process must run efficiently

The anaerobic digestion process must have a constant source of the raw materials (animal or human wastes) for the anaerobic digestion plant to be successful. It may require a farm to have many different reliable sources of feedstock materials, for example, a few cows.

These sources can be challenging to acquire. If the anaerobic digesters run inefficiently, it can cause odor levels which can be a nuisance.

Wrapping it up

Stimulating facts about anaerobic digestion is that it is a viable source of renewable energy and can serve the world needs for clean and green energy. Different sectors should join hands to create more room for it and to improve this cheap source of renewable energy.

A variety of public-private partnership initiatives incentivize the use of wood pellets as a fuel source, but are wood pellets really as eco-friendly as stakeholders claim? 

In this article, we take a closer look at wood pellets, their production, energy efficiency, and sustainability to answer the question, are wood pellets green?

What are wood pellets?

Wood pellets are a type of biomass fuel made from compressed untreated lumber byproducts like shavings, chips, and sawdust. The wood used in wood chips is usually industrial waste from the lumber milling industry, furniture manufacture, or construction, though virgin wood is increasingly used to create pellets for burning.

Wood pellets are created in large volumes by compacting wood waste in a hammer mill, then forcing the massed wood through a die hole to create a sausage-like pellet of the required dimensions. As the pellets are extruded, the lignin in the wood heats up and bonds the pellet constituents together for easy transport, handling, and storage.

Wood pellets are a renewable energy resource

Wood pellets are considered to be renewable because the wood used to create them can be replaced by planting young, fast-growing trees. Pellets use large amounts of the woody waste that the lumber and manufacturing sectors generate, along with leftover virgin wood from coppicing and land management. 

The energy efficiency of wood pellets

Wood pellets are energy efficient compared to other biomass sources like animal manure, biomass crops, and chemical recovery fuels (biodiesel). This is because many biomass fuels contain a lot of moisture that increases the weight and bulk of the fuel but deteriorates its combustion performance.

Wood pellets enhance their energy efficiency by being exceptionally dry. Most commercially used pellets have a moisture content of 10% or less. The pellets are made by condensing wood chips and flakes under high heat and pressure to make an energy-dense pellet that burns drier and hotter. The addition of natural binders like starch that hold the wood chips together. 

Each tonne of wood pellets has an energy content of 4.6–5.1 MWh/ton with a combustion efficiency of up to 85%. This is equivalent to:

• 500 liters of heating oil (enough to heat the average family home for up to six months) 
• 170 gallons of propane (enough to meet the needs of a 500 sq foot home for over 200 days)
• 16,000 feet of natural gas
• 4,775 kWH of electricity

The pellets are uniform and their energy density is high with predictable energy release, unlike the much lower and variable energy density of biomass or solid wood.

How are wood pellets used?

Wood pellets are a versatile fuel source for both consumer and industry use. Here are the main uses of wood pellets: 

1. Domestic heating and cooking

People use wood pellets in domestic wood pellet-burning stoves and furnaces for home heating and cooking. Manufacturers design these stoves to cope with the high temperatures of wood pellets. The energy density of wood pellets makes them great value for money. When used correctly, these stoves produce very little smoke because of the efficient combustion of the pellets.

2. Power plants

Renewable power stations use wood pellets as a sustainable fuel for generating electricity for the grid. A notable example is the UK’s Drax power station, one of the largest in Europe, which was converted from burning coal to using wood pellets imported from the US.

Drax power station burns 7 million tonnes of wood pellets annually to generate up to 5% of the UK’s electricity.

3. Industry

Wood pellets are being adopted as an alternative energy source for industry. Wood pellets can run industrial boilers for generating heat or electricity for industrial processes. Businesses are keen to use wood pellets because of their high burning efficiency, lower carbon emissions, and easy handling and storage of the resource. 

Why are wood pellets considered ‘green’?

The European Union is one of the primary advocates for wood pellets being a green energy solution. This is baked into the 2015 Paris Climate Agreement which states that the burning of trees to generate heat and electricity is carbon-neutral if new trees are planted to replace the trees that are used. 

Trees are considered a valuable carbon sink, and the planted forests will help remove the CO₂ generated by burning from the atmosphere.

But are wood biomass pellets really ‘green’?

The push for the widespread adoption of wood pellets as a leading fuel source is controversial. Governments who are keen to present wood pellets as a viable renewable alternative to coal and gas have highly incentivized wood pellets.

The apparent energy efficiency, low emissions, and sustainability of wood pellets make them attractive to industry stakeholders and consumers. Wood pellets also have the potential to open up new commercial opportunities based on the production and processing of the pellets. But scientists are divided on whether or not wood pellets provide a net environmental benefit. 

Burning wood pellets still produces air pollution

Though burning wood pellets does not generate the same amount of carbon dioxide, sulfur, mercury, and other unwanted emissions as coal, the pellet-burning power stations are still polluting in real-time. Even with the offset of planting new trees, burning wood pellets can still breach emissions limits and harm the health of surrounding communities.

The production of wood pellets is energy intensive

Closer examination of the production of wood pellets reveals it is an industrial process that consumes a lot of energy. Here are some of the most energy-intensive aspects of processing wood into wood pellets:

• Debarking and washing the wood (factories can also use stripped bark as an energy source)
• Drying the wood with gas dryers
• Processing hardwoods rather than pine for the pellets
• Running pellet presses 
• Pressing the pellets down to a 6 to 8 mm diameter using a 500 horsepower press

Export and transportation of wood pellets add to the CO₂ footprint

Wood pellets clock up extensive mileage after manufacturing, using road rail and sea to reach the end user. Transportation, loading, and unloading of the wood chips consume fuel and add to the CO₂ emissions across the lifetime of the pellets. 

Sea transportation has variable but noteworthy energy and CO₂ costs, especially if the pellets are being transported between continents.

The use of virgin wood is controversial

The sources of wood for pellets have included trees specifically cut down for pelleting. This is in contrast to pellets made from wood scraps or treetops, underbrush and smaller branches left over from logging. Drax has been accused of procuring logging licenses to harvest wood from environmentally important forests in British Columbia.

Wood pellets are only renewable if fast-growing trees are replanted

A critical aspect of the sustainability model for burning wood pellets is the replenishment of forestry resources by fast-growing trees. The trees are essential to offset the carbon footprint from burning the wood pellets. 

But the replacement trees used on plantations are not always fast-growing species that can quickly mature into a carbon sink. There is also the issue of privately owned forests and plantations potentially being sold off for development in future with the loss of planted trees.

Wood pellets are heavily subsidized

One of the most important considerations is that the wood pellet industry is heavily subsidized by governments in the US, UK, and EU. The favorable legislation and funding have made wood pellets able to compete with non-renewables, despite their high processing and import/export costs. 

In the EU, wood pellets are seen as a solution for meeting the Renewable Energy Directive target of 20% of energy sources used across the continent being renewable. The pellets are also seen as a cost-effective way to bring down greenhouse gas emissions, even though the pellets are not emissions-free. 

In response to the funding, a range of business interests have invested in building pellet plants and forestry resources for the wood to be used. However, the political interests in making wood pellets ‘work’ may do so at the expense of its long-term viability. 

Rounding up

As you can see, the use of wood pellets as a sustainable fuel source is controversial. Scientists have carefully modeled the sustainability case for wood pellets but many variables are involved, not least the replanting and ongoing maintenance of forestry resources. 

But, without this carefully balanced model, burning wood pellets is just as green as burning anything else. 

Many other states hold the same — or similar — view.

This is just one example of how the public perception of hydropower as a great technological achievement of cheap, renewable energy is rosier than reality.

In other ways as well, as our climate crisis dries up the Earth in many places, any advantages of hydroelectric power are quickly becoming liabilities.

In this article, you’ll find out exactly how the apparent pros of hydroelectric power could actually be viewed as cons — with one exception.

There’s only one real pro of hydroelectric power: energy efficiency 

When hydropower is used on a microscale, it can be an inexpensive source of renewable energy with little to no environmental damage. This is one clear pro of hydroelectric power; it is a relatively efficient source of electricity.

The qualifier relatively is needed because efficiency is dismal when you’re talking about electricity generation.

The U.S. Energy Information Administration states that 60% of all energy used to create electricity is lost during its production.

Let that sink in for a minute, especially in light of the current global energy crisis.

So how exactly is hydroelectric power energy efficient?

What is energy efficiency?

There are a couple of different ways the term energy efficient is used. 

According to the Environmental and Energy Study Institute, energy efficiency is a term that refers to using less energy to perform a task (not wasting it). 

Think of EnergyStar rated appliances as being more energy efficient than others that haven’t earned that status.

Another way to describe energy efficiency is by how much usable energy a source produces (output) from what it has to start with (input). It’s often given as a percentage. 

In the case of electricity, the percentage is a ratio between the energy that a source generates (electricity output) and the sum of all the energy inputs required to create it, multiplied by 100. 

When it comes to making electricity, there are a number of inputs to factor into the levelized cost of electricity (LCOE). These are costs of:

• Capital 
• Fuel 
• Operation
• Environmental damage 
• Down times at the energy plant

After considering all of these elements, here is a graph of the efficiencies of the most common energy sources:

You see that hydroelectric energy far surpasses all types of nonrenewable sources of energy (fossil fuels) in efficiency. 

Hydropower also outdoes the energy efficiency of solar (317% vs. 207%).

Notice from the graph that wind knocks energy efficiency out of the park (1,164%)! Geothermal is better than hydro at 514%.

Notably, unlike hydroelectric power, solar and wind efficiencies are growing rapidly due to active R&D, especially in recent decades.

However, although this pro of hydroelectric power is relatively strong, its value is diminished by all of the major cons of hydroelectric power.

So what’s wrong with hydroelectric power?

Here are six major cons of hydroelectric power. Depending on the source, you may find some of these cons of hydropower are actually presented more like positives but if we are being critical, the conclusions drawn can be vastly different.

1. Hydroelectric power is no longer renewable

Many states actually do not count large-scale hydroelectric power as renewable energy, but they do include small-scale hydroelectric power on their renewable energy balance sheets.

What they consider large or small varies from state to state, but 25-30 MW is usually the dividing line between them.

What are Renewable Portfolio Standards (RPS)?

The renewable energy numbers game that states play is related to their renewable portfolio standards (RPS). This is their method to demonstrate how they are achieving their state-mandated carbon emissions goals. 

States require in their RPS by specified percentage exactly how much electricity sold by utilities comes from renewable resources.  

It’s policies like RPS that drive growth in renewable energy production in the U.S. In fact, since the early 2000s, approximately half of renewables growth is due to RPS, according to the National Conference of State Legislatures.

More recently, some states have introduced Clean Energy Standards (CES). The difference between RPS and CES depends on how a state defines a renewable vs. a clean source of energy. In most cases, clean refers to carbon-free energy sources.

The map below shows you how the states stack up on RPS.

Here are how the states with ambitious climate goals compare on RPS/CES:

However, our point about hydroelectric power as no longer renewable is not simply to be in agreement with many states.

It is much larger than this.

Effect of our climate crisis on hydroelectric power

The August 18th, 2022 front page of the New York Times sums up the effect of our climate crisis on hydropower nicely: 

“Heat and drought have reduced hydropower in Norway, threatened nuclear reactors in France and crimped coal transport in Germany.”

And that’s just Europe. In only two months.

Here’s how Europe’s energy crisis is devolving on the infographic below. See how hydroelectric is down. Nuclear is down due to the increased temperature of water making it impossible to cool down radioactive rods.

Note the double-digit growth in solar and wind. Unfortunately, coal is picking back up due to Russian president Putin shutting off gas to some regions. The small rise in gas is due to increased gas imports from the U.S.

As widespread, prolonged drought — termed aridification — occurs the world over, humans must acknowledge then rapidly adapt to the fact that if carbon emissions are not drastically reduced this decade, freshwater will become increasingly difficult to find.

Water is the new gold.

For example, as the deadline passes for stakeholder states dependent on the Colorado River for life and livelihoods to draw up a plan for water conservation and equitable allocation as river levels plummet due to our climate crisis, the federal government will step in and do it for them to avert catastrophic collapse.

This could lead to armed conflict among thousands — if not millions — of people as water scarcity intensifies.

So, when mega-drought conditions are slowly expanding across the nation, maybe it’s not a good idea to include hydroelectric power in the reliable energy supply mix? All other forms of energy production (except biomass) use a lot less water as the diagram below shows.

(Note: PV = photovoltaic or solar; L= liter; MWh = megawatt hour. 1 MWh = 1 million watt hours.)

Effect of our climate crisis on hydroelectric power in California

The Colorado River feeds the two largest reservoirs (when filled to capacity) in the U.S.: Lakes Mead and Powell.

Here’s a short video on the amazing Colorado River:

Lake Mead is the water source for more than 25 million people and supplies agricultural land across three states. Currently, the mega-drought has pushed it to its lowest level ever. 

The extreme drought in the U.S. West is so bad that you can see its effect on the Colorado River and the major hydroelectric dams it feeds from space.

In California, hydroelectric power plants are shutting down — sometimes for the first time in history — as reservoir levels drop to their lowest levels ever. Climate crisis-intensified heatwaves driving encroaching aridification (low snowpack levels and less rain are the cause).

The state imported 30% of its energy in 2020 but is still struggling to make up for hydropower shutdowns resulting in 3.5 GW power shortfalls. So, power outages become commonplace, if not because of hydropower deficits, then for outages to protect grid infrastructure during wildfire season. (1 GW = 1 billion watts.)

The future of hydroelectric power in a climate crisis

Hydroelectric power water deficiencies due to our climate crisis severely restricting the availability of freshwater are not just in the USA and Europe as discussed in the preceding sections. 

Heavily industrial parts of China are feeling the heat, too, in the longest heatwave in world history (70+ days) now in Summer 2022. Some municipalities are shutting down factories for days at a time to protect the grid. 

Consequently, China’s economy has already contracted this year. Only 2.8% growth is expected this year (down from the country’s projected 5.5%). 

Since much of the world’s goods originate in China, a cascade effect resulting in supply chain disruptions leading to further economic downturns is predicted globally.

Furthermore, many aging dams are literally falling apart, unable to withstand extreme weather. For example, under the onslaught of torrential rains — also an effect of our climate crisis — they could collapse, triggering massive evacuations or mortalities.

Perceptive readers see where this is going.

It is unwise — in fact, foolish — for governments to count on freshwater as being readily available any more for hydroelectric power. Especially when there are renewable energy sources with steady, assured inputs: solar, wind, and geothermal energies.

In fact, a 2022 study clearly forewarns that because of global heating leading to increased aridification, the future of hydroelectric power in the U.S. and elsewhere looks grim.

Here are just a few of the astounding predictions from that study:

•  61% of all global hydroelectric dams will be located in water basins with very high or extreme risk for droughts, floods or both by 2050. 
• By or before 2050, 20% of existing hydroelectric dams will be in areas of high flood risk. (Today, it’s a 4% risk.) 
• Currently, 2% of planned dams are in water basins with high flood risk. By 2050, that risk increases to 40%.
• 80% of all planned dams are in areas with high risk to further biodiversity loss. (Since 1970, freshwater fish populations have declined by 84%, and hydroelectric dams are considered the major cause.)  

What is not emphasized enough is that the planet is in a record La Niña, or “cool phase,” of the El Niño Southern Oscillation (ENSO).

Can you imagine what the temperature — and the drought level — will be when the hotter El Niño returns in 2023?

On a somewhat optimistic note, however, seawater is readily available as a tidal hydroelectric power source. Hopefully, marine hydrokinetic energy research and development will scale up soon on a grand scale to complement solar, wind, and geothermal energies.

2. Hydroelectric power is environmentally destructive

There are several aspects of hydroelectric power that are environmentally destructive. They fundamentally alter river ecosystems and the surrounding wildlife habitat.

Fish ladders

Readers may smile at the notion of fish ladders on some — but not all — conventional hydroelectric projects and believe that hydroelectric power is eco-friendly.

As a series of ascending pools (steps), fish ladders, or similar elevators, flumes, or bypass channels to get around turbines, are the most commonly used methods to help the fish move through dams.

Other ways to accomplish this feat include barges, tankers, trucks, or even an airplane!

Dams with no fish passage modification in the Columbia River Basin block more than 40% of the native habitat once freely accessible to salmon and steelhead trout before dam construction.

Here is a schematic that shows one of the methods to allow fish to get by a dam.

Installing fish ladders was a part of most hydroelectric dam projects since the 1890s. In fact, the Federal Power Act of 1920, the Fish and Wildlife Coordination Act of 1934, and the Northwest Power Act of 1980 are examples of just three laws requiring fish passages at all hydroelectric dams on public lands.

Unfortunately, not all dam builders or local governments took the laws seriously. 

Only with the insistence of fish advocates to at least save some native salmon and other fish species was fish ladder technology and design taken seriously and equipment installed. Survival rates slowly increased.

Most of the time. At least for adult fish.

Sadly, in some cases such as in a study from the Northeast U.S., only 3% of fish make it home to their spawning ground even with a ladder present beside the dam. 

Assisting juvenile fish around the dams was a different story.

Results from the Pacific Northwest are mixed for juveniles. Some years have a survival rate of <3%, while others can be as high as 60%. Overall, success in terms of higher survival rates increased in the 1990s and later compared to those of the 1960s, likely due to advanced methods and more diligence.

Below is a diagram of one passage setup to assist juvenile fish around hydroelectric dams.

Tragically, it’s not just the fish ladders that are literal stumbling blocks for fish trying to swim up river or head out to sea.

Warmer water temperatures and lower river levels due to our climate crisis are perfect conditions to allow a fish parasite to thrive in Idaho to California rivers. As a result, massive fish kills in the hundreds of thousands of several species — including endangered Chinook salmon — become common.

Reservoir construction

In addition, the construction of reservoirs has led to massive destruction of habitat, including that of many endangered species.

A large hydroelectric power plant built on level terrain may inundate thousands of square miles, wiping out forests, wildlife habitat, and farms.

Entire human villages and towns are relocated in many cases as well. This uproots identity-forming cultural attachments to the land.

As the world faces the 6th mass extinction of species, wild nature is further encroached upon to make way for roads, cattle ranching, soy and corn crops for animal feed, palm oil plantations, and new housing developments. More destruction to make way for additional hydroelectric power plants doesn’t make biological or economic sense.

Without biodiversity, human civilization is at risk of collapse, too.

Here are some stunning statistics on how dams have led to massive biodiversity losses in the U.S. according to the group American Rivers:

• Seven dams on the Coosa River in Alabama led to more than thirty freshwater species going extinct.
• East Coast populations of Atlantic salmon have been decimated by dams blocking access to spawning 
• 29% of West Coast salmon populations are now gone. One-third of the remaining salmon populations are threatened or endangered.

Environmental concerns with reservoir water

The water in reservoirs is stagnant. There are several problems with this.

Algal blooms in reservoirs

Nutrient buildup in reservoirs leads to algal blooms, sometimes toxic ones, aggravated by climate crisis-induced warming. Since the algae are consuming much of the oxygen, little remains for fish, leading to higher fish mortality.

Methane production in reservoirs

Underwater plants, meanwhile, also suffer from lack of oxygen consumed by algae. As the plants die and rot, they release methane, a potent greenhouse gas that contributes significantly more to global heating than carbon dioxide.   

Recent research concludes that previous estimations on exactly how much methane is released from dam reservoir surfaces are too low. Current studies show reservoir surfaces release 25% more methane than previously thought.

In other words, more hydroelectric dams will accelerate our climate crisis. This fact is more evidence to support the conclusion that hydroelectric power is not clean energy.

Higher evaporation rate in reservoirs

Thirdly, unmoving water evaporates more quickly than moving river water. Thus, in a prolonged drought during heatwaves, reservoir levels plummet. Shutdowns of energy production result when levels get too low as described below.

Sedimentation in reservoirs

According to the U.S. Bureau of Reclamation, the buildup of sediments in reservoirs from agricultural runoff and heavy rains is a major problem. Up to 35% of the total water holding capacity of all U.S. dams has been reduced over time due to sediment loading alone (not counting effects of global heating that causes rapid water loss through evaporation). 

As dams age, sedimentation worsens and reduces the normal lifespan of functional dams, presenting multiple problems including:

• Decrease in reservoir storage capacity 
• Plugging up dam outlets and reservoir water intakes 
• Lowering water quality, negatively impacting both aquatic life and human recreation 
• Decrease in nutrient flows downstream, even as far away as coastal ecosystems 
• Increase in degradation of downstream habitats

The last point may seem counter-intuitive. Wouldn’t sediment-free water help downstream habitats?

“Hungry water” in hydroelectric power

Researchers describe the water that has left its sediment behind in reservoirs as “hungry water.” It is likely to accelerate erosion in the downstream river’s channels, banks, and beaches while it’s picking up sediment to replace what it lost back in the reservoir. In the process, this hungry water erases critical habitat features along and under the downstream water channels. These features, such as wetlands, pools, and runs, are needed for wildlife.

Viral spillover

Additionally, as wild animals’ habitat is severely reduced by human encroachment, the likelihood of viral spillover events from wild animals to humans increases. The chance of this happening also increases with climate change.

While humanity is still dealing with SARS-CoV-2, the virus that causes Covid-19, it certainly doesn’t need more pandemics.

River scarcity

For 100 years, the U.S. has built more dams than any other country. So it’s logical to ask: Is there any space left on rivers for more dams?

Unbelievably, thousands of new hydroelectric dams are planned or under construction worldwide, even in protected areas, and some on free-flowing, wild rivers. This construction would affect approximately 200,000 miles of river, surrounding ecosystems, and human settlements. 

If completed, the 2010 installed energy capacity from hydroelectric power (1,000 GW) would double in the next few decades by new hydropower plants.

That’s a big “if” because today, on a global scale, most investment is in solar and wind — not hydropower. In fact, the corporation that built the world’s large hydropower plant, the Three Gorges Dam in China, invests heavily in wind and solar.

That corporation is probably very relieved today it did so.

Low water levels in the Yangtze River are forcing widespread closures in the region due to megadrought and prolonged heatwaves as this video shows.

In the U.S., because of the dam collapses in California and Michigan in recent years, there’s no frenzy to build more dams like there was in the early 1900s. A drying climate is cementing that attitude.

However, there is still a lot of interest in the U.S. in converting smaller, non-powered existing dams to small-scale hydropower plants.

Several recent studies in China, Norway, and Spain have shown that small-scale hydroelectric power (<30 MW) is not cost-effective and comes at huge social and environmental costs. It takes significant amounts of money to fortify and equip non-powered dams so that they could generate just a relative trickle of electricity. 

Natural resources are limited, even more so in a climate emergency. Humans must use them wisely if civilization is to make it to 2050. More hydroelectric power plants of any size can’t be justified.

3. Hydroelectric power is not sustainable

The material used to construct hydroelectric power plants is primarily cement, one of the most unsustainable materials on the planet, that when set, becomes concrete.

Interestingly, cement is the most widely used material on Earth, after water.

To give you some idea of how much concrete (in cubic yards) is in a hydropower dam and associated structures, here are two examples:

• Hoover Dam in Nevada: 4.36 million 
• Grand Coulee Dam in Washington: 12 million

The concrete in the Hoover Dam, according to the U.S. Bureau of Reclamation (BR),

“…would build a monument 100 feet square and 2-1/2 miles high; would rise higher than the 1,250-foot-tall Empire State Building if placed on an ordinary city block; or would pave a standard highway 16 feet wide, from San Francisco to New York City.”

Similarly, the concrete in the Grand Coulee Dam, according to the BR,

“…could build a sidewalk four feet wide and four inches thick and wrap it twice around the equator (50,000 miles). You could build a highway from Seattle, Washington to Miami, Florida.”

Concrete is unsustainable for two reasons. First, the extremely high heat needed to manufacture it requires energy from burning fossil fuels, which produces greenhouse gases and contributes to our climate crisis. Cement also releases carbon dioxide in a chemical reaction while being mixed with other materials during manufacture. 

If cement were a country, it would be the 8th largest carbon emitter in the world.

Here’s a diagram to show you just how bad the concrete industry is in terms of carbon emissions:

Furthermore, most concrete is not recycled although in theory it can be. A study in California showed only 2-8% of concrete was recycled. The rest is landfilled after demolition.

The good news is that Solidia is making significant strides in greening cement. Carbicrete in Canada makes carbon-negative concrete. But there is still a long way to go to get the entire cement industry on board.

4. Electricity from hydroelectric power is not the cheapest available

Hydroelectric power advocates boast that it’s the cheapest electricity source known today.

Solar and onshore wind captured that spot in 2022.

Here is the breakdown measured in dollars per kilowatt hour ($/kWh) for the most common sources of electricity:

As noted above, in a climate crisis that is already leading to economic downturns on both national and personal levels, humans must spend limited resources, including money, wisely. 

This is more reason to choose solar, wind or geothermal to meet your household energy needs.

5. Hydroelectric power is not cost-effective to produce

Even though it is commonly believed that operating costs are minimal for hydroelectric power, comprehensive research in 2014 showed this was not the case. 

Of 245 large dams reviewed in that study, all built between 1934 and 2007, they were too expensive to yield a positive return — without even taking into account environmental costs. In fact, the average costs were 96% higher than the estimated costs^⁠. Additionally, on average, they took 44% longer to build than anticipated, decreasing the return on investment.

So, in drought-ridden areas, it may be permissible to allow hydroelectric power plants to function as long as possible under their current license, but then let the licenses expire.

Certainly, no new hydroelectric projects should be initiated anywhere, including renovating small non-power dams for hydroelectric power as explained above. Doing so is not economically viable.

Instead, focusing on tidal energy development — where no dams are required — looks promising since it relies on unlimited seawater.

Of course, renewable solar, wind, and geothermal energies must center predominantly in the future energy portfolio of humanity.

6. Aging hydroelectric dams are a big risk in intense floods

Just as our climate crisis is responsible for supercharging extreme drought worldwide, it is also the reason for intense flash flooding. When aging or poorly constructed dams are in the flood zone, disasters aren’t too far behind.

Dangerously, the world is entering a period of “mass aging” of dams. Tens of thousands of dams are 50 years old. Many others are approaching 100 years. 

In the U.S., by 2030, 70% of dams will be over 50 years old. In 2019, the U.S. Army Corps of Engineers estimated there are approximately 15,600 dams classified as “high-hazard Structures.” Thus, it’s no surprise the American Corps of Civil Engineers gave the U.S. a “D” grade on its dams in the Group’s 2017 Report Card.

There are some dam removal projects going on in many countries, including the U.S., but these are costly and many take years to complete. So far, the nonprofit group American Rivers estimates only 1,956 dams (<2%) have been removed so far in the U.S. 

The Biden Administration recently signed into law the Infrastructure Investment and Jobs Act. It includes $2.4 billion for the removal or retrofit of dams. This is a start, but it’s not enough.

Meanwhile, flash flooding is intensifying everywhere. 

In 2017, the tallest dam in the U.S., Oroville Dam in California, partially failed. Heavy rains damaged the main and emergency spillways, forcing the evacuation of 188,000 people in three counties. Repairs cost over $1.1 billion. Operations were shut down for three weeks.

As a second example, in 2021, two hydroelectric dams collapsed in Michigan, forcing the evacuation of 10,000 people and causing millions of dollars in property damage.

Like most dams in the U.S., they were non-federally owned. Since the owners declared bankruptcy, it’s unlikely flood victims will win in court for damages.

So, building new hydroelectric dams in the 21st century climate crisis is clearly a high-risk investment. Fortunately, significantly less risky solar, wind, and geothermal energies exist to power our homes and businesses.

Bottom line: hydropower may not be the clean energy source we need for the future

The only pro of hydroelectric power is that it is a relatively efficient form of energy.

It’s common to read on the internet that the major pros of hydroelectric power are that it’s:

1. Renewable energy
2. A reliable energy source
3. Very energy efficient
4. Cheap source of electricity
5. Cost-effective to build and operate
6. Able to meet peak electrical demand.

Sadly, none of these statements is true about hydroelectric power, especially in our climate emergency.

Global heating is drying up the Earth with mega-droughts all over. Scientists predict that unless carbon emissions are drastically reduced by 2030, there will be intensifying aridification (drying) on a global scale. 

Since the water cycle is no longer natural — also because of our climate crisis — water should not be viewed as a renewable resource like it once was. Water has become different from solar, wind, and geothermal energy — all of which are truly renewable. 

So, without enough — or any — water, hydroelectric power plants won’t generate electricity, let alone meet high demand.

It’s also true that major cons of hydroelectric power have become worse over time:

1. Adverse environmental impact
2. Risky aging dams

With increasing deforestation and massive loss of biodiversity worldwide, building more dams and reservoirs will restrict wild nature even more. Doing so will bring wild animals in closer, more frequent contact with humans, making spillover events of viruses infecting humans more likely.

Today, most rivers that meet the requirements for massive hydropower have already been dammed. If there were to be more upstream diversions of freshwater — already a precious resource — to build more power plants, communities and wildlife downstream would receive even less water, if any. 

Regardless of where opinion falls when it comes to determining just how ‘green’ hydropower is, it’s important to be clear on what, exactly, hydroelectric energy entails, to better understand its wider impact on the environment.

What is hydroelectric power?

Hydroelectric power refers to using the kinetic energy of moving water or the potential energy of unmoving water to generate electricity.

In most types of hydropower generation, the process occurs in five steps:

1. A water flow turns a turbine connected to a generator in a powerhouse.
2. The generator’s rotational energy is converted to electricity.
3. Electricity flows from the generator to a utility substation (transmission yard) where its voltage is increased.
4. Then electricity travels long distances via transmission lines to the power grid.
5. Electricity is delivered to businesses and consumers like you.

History of hydroelectric power

As described in the U.S. Federal Energy Regulatory Commission (FERC) document titled Hydropower Primer, water has been used for thousands of years in many parts of the world to create mechanical power to grind grain.

Over 200 years ago in the United States, the first dams were constructed to generate mechanical power at grain and paper mills as well as other industries.

The world’s first hydroelectric power plant was built in 1882 on the Fox River in Appleton, WI.

In the early to mid-1900s, as funded under FDR’s New Deal, many dams used for mechanical power were converted to hydroelectric plants. Additionally, hundreds of new plants were built just as the national electric grid was being developed.

The 1940s saw the biggest contribution of hydroelectric power to electricity generation in the U.S.: 40%.

Below is a map of where the federally-owned hydroelectric projects are located along with the hydropower plants owned by private companies, municipalities, electric co-ops, or private citizens. (The majority of all hydropower plants in the U.S. are non-federal.)

Current state of hydroelectric power in the United States

In 2021, according to the U.S. Energy Information Administration (EIA), only 6.5% of all utility-scale electricity produced in the U.S. came from conventional hydropower, defined as hydroelectricity generated from “natural streamflow.” 

With the exception of Mississippi and Delaware, all U.S. states have some form of conventional hydroelectric power:

To find out the latest reservoir storage levels and historical comparisons for many U.S. hydropower plants, you can use this interactive tool. If you’re one of millions of people who rely on the shrinking Colorado River for potable water or electricity, this tool is very informative.

At the very least, it could prepare you for upcoming water rationing or water bans in your area.

The future of hydroelectric power in the United States

According to the American Society of Civil Engineers, there are approximately 91,000 dams in the U.S. Only 3% actually produce electricity today. The majority of dams were built for commercial navigation, irrigation, water storage, or flood control.

After extensive review and analysis, experts estimate that suitable non-powered dams could generate only 4,800 MW of additional hydroelectric capacity after renovations and repairs. (1 MW = 1,000 kilowatts.) This is the equivalent of only 0.0048 terawatts or a mere 0.00012% of all the electricity used in the U.S. in 2021.

So the question of whether it makes economic sense to invest in hydroelectric power development by converting non-powered dams, especially when solar, wind, and geothermal energies are available as electricity sources, is very pertinent.

How does hydroelectric power work?

Have you ever seen a historic grist mill on the back roads of America, like the one in the photo below? 

That water wheel works on the same principle as today’s hydroelectric plants.

FERC’s Hydropower Primer provides a clear and concise description of how hydroelectric power works. Here is a brief summary.

Turbines in hydroelectric power

Since the early 1820s, three major types of “water wheels” have been invented. They were dubbed  “turbines” from the Latin word turbo meaning whirlwind or whirl by Benoît Fourneyron who invented the earliest type.

There are the three main types of turbines used in hydroelectric projects today:

1. Pelton
2. Francis
3. Kaplan

Here are schematic drawings detailing their differences:

To understand the different ways each turbine type operates, it’s helpful to know the basic principles of how water flows in hydropower setups.

Hydraulic head

In order to have hydropower at all, there must be a difference in elevation through which water falls. 

As it’s moving downward, the water possesses kinetic energy.

But even when the water is perfectly still in an upper reservoir behind a dam, it possesses that same energy in a different form called potential energy.   

The vertical change in elevation between the reservoir water level (head) and the downstream water (tailwater) is known as the hydraulic head. 

As you can probably guess, the world’s largest hydroelectric plants (30+ MW) have huge hydraulic heads of hundreds of feet. 

By contrast, those producing only a couple megawatts of electricity have considerably smaller hydraulic heads, even under 100 ft.

Flow

There is another factor involved with hydropower that’s important in understanding how hydroelectric power works. It’s called flow.

In simplest terms, flow is the volume of water passing a certain point in a specified amount of time. 

As an example of flow, imagine filling up a bathtub. When the flow rate is high, the tub will fill up fast. But when it’s slow, you could spend 20 minutes or more and still not fill even half of it up.

Using both concepts, here are some generalities about how hydroelectric power works:

• Water possesses more potential energy (which can be converted to more electricity) when both the hydraulic head and the rate of water flow are high.
• If a hydroelectric plant has a small rate of flow, it must have a huge hydraulic head to compensate in order to generate significant electricity. 
• If a hydroelectric plant doesn’t have great vertical elevation (meaning its hydraulic head is low), a very high flow rate can still generate substantial amounts of electricity.

Keeping this background in mind, here are the hydraulic situations for each major type of turbine that will produce the most electricity.

Hydroelectric power dams

There are many types of dams used in hydroelectric power. They serve to hold back water in reservoirs. Here are the major types of dams used today:

Type of Dam	Photo of Dam
Gravity
Arch
Roller Compacted Concrete (RCC)
Slab and Buttress
Embankment
Rockfill

What are the 4 main types of hydroelectric power?

The U.S. Federal Energy Regulatory Commission (FERC) categorizes hydroelectric power into four general types:

1. Conventional Impoundment (dam with reservoir)
2. Conventional Diversion (run-of-river)
3. Pumped Storage 
4. Marine and Hydrokinetic (MHK)

In this article, we focus on the first three types of hydroelectric power. For more information on the fourth type, see this article.

1. Conventional Impoundment (dam with reservoir)

The most common type of hydroelectric dam has a wide and deep reservoir of water behind it. These may be used as recreational facilities for picnicking, boating, or fishing.

The major similarity among all types of impoundment hydropower projects is that the powerhouse is close to the reservoir.

Here is a diagram of what a conventional impoundment hydroelectric plant looks like:

2. Conventional Diversion (run-of-river)

Hydroelectric power plants located on rivers where salmon and other fish species return from the sea for spawning going upstream frequently have fish ladders to allow returning fish to get through.

The fish ladders are situated close to the main water flow in a diversion channel. They are not literal ladders. They are bypass channels for fish to get to their ancestral spawning areas. 

Often in diversion dams, the powerhouse is located far from the reservoir, maybe even a few miles away.

Here is a diagram of a conventional diversion hydroelectric project:

3. Pumped Storage

Built mostly in the 1960s-1980s, pumped storage facilities are used to supply energy and/or water on demand to nuclear or fossil fuel power plants adjacent to them.

During off-peak periods when electric rates may be cheaper, water is pumped from a lower reservoir to a higher one. This is an energy-intensive process.

When electricity is needed (high demand), water is released to generate it. 

In 2021 in the U.S., there were only 23 TW hours of electricity created from pumped storage projects in 18 states out of 3,930 TW hours used. (1 TW = 1 trillion watts.)

Pumped storage systems use more electricity to pump water upwards than they produce. So, these facilities have net negative electricity generation.

Here is a diagram of a typical pumped storage hydroelectric setup:

4. Marine and Hydrokinetic (MHK)

Also referred to as tidal energy, marine and hydrokinetic energy use ocean waves, currents, tides, or inland waterways to generate energy.

So, no powerhouse or dam is necessary. An energy-generating apparatus (a turbine or similar) is placed directly in the water. 

The ocean’s kinetic energy or sub-surface pressure difference is transformed into electricity.

As of yet, MHK energy is still in its R&D phase.

Here is a schematic of one example of an MHK project:

FAQs about hydroelectric power

Here are a few frequently asked questions and answers about hydroelectric power. 

1. What are the top countries producing hydroelectric power in 2020?

The top four producers of hydroelectric power (in terawatt hours, TWh) in 2020: 

1. China (1,355)
2. Brazil (391)
3. Canada (382)
4. United States (286)

Note: One TWh = 1 billion kilowatt hours = 1 trillion watt-hours.

2. What is a microhydropower plant?

Green homesteaders, preppers, and small communities or businesses with a knack for DIY projects and a readily accessible stream or river on their property may consider building a DIY microhydro power plant as a source of off-grid renewable energy.

“Microhydropower can be one of the most simple and consistent forms or renewable energy on your property.”

United States Department of Energy (DOE)

In fact, the DOE has an entire page devoted to planning your very own DIY microhydro power plant!

A microhydro power plant usually generates 100 kW of electricity. Since the average household needs 5-6 kW of energy to run comfortably, a microhydro setup + battery storage could supply a small neighborhood, farm, or ranch easily. 

In conjunction with solar, wind, or geothermal energy, a microhydro system with battery storage would guarantee complete energy independence from the public utility grid. 

The type of hydroelectric power that works most sustainably and cheaply in micro form is a run-of-river system. Below is a diagram of the basic setup:

For more details on the nuts and bolts of such a DIY home energy project from start to finish, Manfred Mornhinweg in Chile documents his DIY adventures here.

Note: Even though the DOE didn’t mention it on their pages, be sure to get any necessary permits from your local jurisdiction before undertaking a DIY microhydro power project.

3. Can non-powered dams be converted to produce hydroelectric power?

It is possible to convert non-powered dams to produce hydroelectric power in some cases. Because these dams are older, they will require significant and costly renovation and retrofit. Whether it is economically feasible or not is questionable, especially in a climate crisis.

A group of researchers published a 2019 article asserting that due to environmental, safety, and cost concerns, there is a growing tendency in the U.S. to decommission aging dams or allow licenses to expire, including those with hydroelectric capacity.

The researchers hypothesized that photovoltaic (PV) panels could produce the equivalent amount of electricity generated today from hydroelectric power on only 13% of the land taken up by the reservoirs slated to be torn down. 

Furthermore, they calculate that if all the dams were removed and only 50% of the freed-up land was used by PV, the solar panels could produce over three times as much electricity.

This research suggests the heyday of hydroelectric power is over and solar power — the cheapest form of electricity in history — is here to take its place.

The installation of solar panels is one of the more popular strategies for reducing dependence on the grid, with 6% of US homeowners owning solar panels and a further 49% giving solar panel installation serious thought. 

Adding solar panels to make the most of long hot summers and savings on sky-high AC bills makes a lot of sense. But home solar panels are incredibly expensive, even with generous state and federal tax incentives. 

Owning solar panels is a big investment, but is leasing any cheaper in the long run?

To help you make the right decisions we have produced this guide on leasing vs buying solar panels. Our guide to leasing vs buying solar panels should help you evaluate the pros and cons – of leasing or buying solar panels on your property and includes the key differences between buying and leasing solar panels.

So set aside a few moments to read this informative guide which should equip you with the information you need to decide whether buying or leasing solar panels is the right option for you.

Leasing vs buying solar panels – what’s the difference?

The key difference between buying and leasing your solar panels comes down to one word: ownership. 

Both options are going to cut down your electricity bills but only one lets you own the panels. With a purchased solar panel installation you are the outright owner of the system, whereas leased solar panels are installed on your property, but owned by the company that installed them. 

Let’s take a closer look at the features of these two arrangements. 

Leasing solar panels 

Taking out a solar lease is a common option for property owners who want to install solar panels but do not have the $20,000 up front to purchase a system outright. Solar panel system prices have dropped by at least 70% in the last decade but they are still pricey. By leasing, you pay a solar company a low monthly fee while enjoying the low bills that come with solar panels.

For solar leases, you deal with the solar company to set up your solar panel system, while a separate financing company administrates the lease on their behalf. You handle the monthly payments regardless of the amount of energy the panels actually generate. 

The solar company owns and is responsible for the maintenance of the system.

With leasing, you still get all the benefits of the electricity generated on your property. If you produce more electricity than your property needs, the panels send the excess power to the grid, earning you metering benefits that drive down your bills even further. But you’ll still pay for the energy you use when solar production is low. 

Buying solar panels

If you want to fully own your solar power system, buy it. There are several ways in which you can have your ideal solar panel system, complete with panels installed in your home:

1. Purchase a turnkey solution that includes both the solar panels and their wiring into your home’s electricity supply with the necessary metering and controls. Pay for the panels and installation in whole, upfront.

2. Purchase a turnkey solution that includes both the solar panels and their wiring into your home’s electricity supply with the necessary metering and controls. Pay for the panels and installation in installments using a loan or hire-purchase arrangement (HPA).

3. Purchase solar panels and hire a contractor to install them on your property.

4. Buy solar panels and install them yourself with the help of a local electrician.

Most homeowners value the expertise of a solar installer who can source and install suitable solar panels for the property. If you cannot pay in full for the solar panels, the company works with partner companies that arrange the financing for the panels. 

This arrangement is known in the industry as a solar loan and involves monthly payments for a fixed term. 

Owning solar panels comes with maintenance responsibilities that leaseholders do not have. However, the energy that is generated and all the long-term savings are 100% yours. 

Pros and cons of leasing vs buying solar panels

Now you understand the difference between buying and leasing solar panels for your home, it’s important to know the implications of each option. There are important pros and cons for leasing (and for buying) that will affect your return on the investment of installing your solar panels. 

Here’s what you need to know:

Pros of leasing your solar panels 

There are plenty of advantages of leasing vs buying solar panels. Let’s take at some of the pros, to help determine if the positives potentially outweigh the negatives. 

1. Almost zero upfront cost

If you cannot pay the upfront cost of solar panels but need some relief from sky-high power bills, solar panel system contracts can provide lease arrangements that provide turnkey installations of panels with almost no immediate costs. Simply keep up with your monthly repayments for the duration of the lease.

2. Maintenance-free solar panels

A big benefit of leasing solar panels is that you escape the responsibility and cost of maintenance and upkeep for them. This aspect of the leasing arrangement is reassuring, because you’ll always know that the solar company will handle any problems.

Cons of leasing solar panels

Along with positives, there are also downsides to leasing vs buying solar panels. Some of these are well known negatives, and you have to be careful to make sure you don’t get stung:

1. You don’t own the solar panels

The bottom line is that with leased solar panels, you don’t own the panels, meaning you’ll miss out on some pretty important benefits of owning them, such as increasing your property value. The savings you’ll enjoy would be better with ownership as they aren’t offset by monthly installments. 

2. Monthly bills

After all the effort to reduce monthly bills by generating solar power, with leasing, you get an additional bill. But for most solar panel lease arrangements you are switching a larger energy bill for a smaller electricity bill and your lease payment.

Solar lease payments can be a bit of a headache because they often increase year-on-year because the lease payment is pegged to any predicted price rises in electricity. Another issue is that if you generate little solar energy with your leased solar panels, you will still pay for power from the grid while paying a fixed lease payment.

3. Missing out on incentives and tax breaks 

When you lease solar panels, you don’t own the system you’ve had installed, making you ineligible for a variety of state and federal rebates and incentives for solar panels. 

These incentives are paid to the lease company instead. This is an important reason to consider buying as incentives often make buying solar panels great value for money, as we explain further on. 

4. Introducing difficulties in selling your home

Once leased solar panels are on your home, you have someone else’s property and that can complicate things if you want to sell your home. The lease contract may mean that the panels have to remain in place for a certain period, or you may have to transfer the lease to a new owner. 

If you cannot transfer the panels, you face significant costs to break the lease. Some companies may provide the option of buying back the solar panels which could increase the value of your home but without this option you’re stuck!

Pros of buying your solar panels 

If you have the cash, owning your solar panels is a great investment in your property. Here are the need-to-know benefits:

You own your solar panels

This means that the panels, electronic hardware and‌ the energy that is generated is 100% yours! Even if you pay by installments, you will have no further bills once the payment term is finished, leading to substantial long-term savings on energy costs. 

You are eligible for SRECs

Did you know you can generate a decent income from your solar panels with solar renewable energy certificates (SRECs)? Most state offer SRECs, a financial instrument that pays you money for each MWh of electricity your panels generate for the grid. The exact amount you earn varies by state but SRECs are only available to solar panel owners. 

You are eligible for federal tax credit

People who lease their solar panels are missing out on a variety of federal and state incentives for generating renewable energy. Federal tax credits are a great reason to own because they can save you up to 30% of the cost of purchasing and installing your solar panel. If you lease, the solar company gets national incentives and tax credits your property earns. 

Increase in house value

Solar panels provide an appreciable uplift in the value of your property, as much as 5%. This is not only because the property now has its own renewable energy source but also because of the SRECs it earns. 

This will make your property highly desirable to prospective buyers as your property generates energy as well as income.

Cons of buying solar panels 

While there are plenty of reasons to buy and own solar panels, it also has its disadvantages too. The main downsides of ownership are:

The cost

If you want to own your solar panels, you’re going to have to pay out a large sum. The Solar Industries Association (SEIA) reports that the average residential solar panel system costs almost $3 per watt. This means you be paying at least $11,000 for a 5 kW system. The average homeowner needs to be prepared to spend up to $20,000 to own their own solar panels.

Maintenance responsibilities

Once you own your solar panels, you are 100% responsible for the condition and maintenance, especially if you have cleared a warranty period. Leaseholders don’t have the stress and expense of dealing with damage or breakdowns as solar panel companies include it in their monthly fee. Remember to keep the panels clean so they can capture sunlight efficiently.

Potential for disappointing performance 

Nothing could be worse than paying out a capital sum for your solar panels and finding that they don’t generate the amount of electricity you expect. This is a real risk for any solar panel installation. 

Many homeowners hire the services of professional solar trackers who plot the course of the sun over the property for a period to calculate the best orientation of solar panels. 

Solar panels stay with the property

Solar panels are often purchased for a ‘forever’ home simply because owners invest in them for a lifetime of benefit and do not intend to move. Though you could technically remove the panels and hardware from your property if you move home, the solar panels will have been specifically fabricated, oriented, and installed for the property and may not be as effective elsewhere. 

Leasing vs buying solar panels – so which is better?

The decision to opt on leasing vs buying solar panels really depends on your personal circumstances and your finances in particular. Here are some considerations that can help you decide if leasing or ownership is going to be better for you: 

Your age

If you are older and approaching retirement, leasing may make great sense.

Rather than spending a lump sum from your savings or a future inheritance on outright ownership, you can pay a monthly fee out of your pension while reducing your utility bill. You also don’t have the stress or hassle of maintenance.

Young families should definitely buy. If you are still under forty, purchasing solar panels is one of the top two best investments you can make, right alongside buying your own house. And that investment gets even better if you live in a region where you get credit for the extra energy you create. You have the time to enjoy long-term savings and pay off a loan for the purchase.

There are also ways to go solar without upfront costs. Check our guide to free solar panels to learn more about the options.

Your cash flow

If you are asset-poor but cash-rich, you may find it convenient to get the benefits of solar panels for a regular monthly fee. Leasing solar panels can free you up from the details and you don’t have the worry of wondering if the panels are working optimally. 

However, if the opposite is true and you have low cash flow, home solar panels that produce a lot of energy could create a meaningful income. You can also take advantage of the heavy subsidies and tax breaks that come with adding solar panels to your home. 

Your lifestyle 

If you don’t have time for managing your panels, just lease them. Leasing frees you up from tracking the efficiency of your panels. The company you rent them from will do that, using sophisticated technology that might not be available to you if you buy.

Also, if you lease your panels, you don’t have to worry about carrying insurance on them or fixing and maintaining your panels. That, too, will be the responsibility of the provider.

Your family

If you want to install solar panels, the opinions of your spouse or partner and family are important. Solar panels are a big purchase and if your spouse doesn’t want the financial commitment of a purchase, then leasing solar panels may well be a suitable compromise. 

Your business

The benefits of buying a solar array big enough to power your business are nearly endless. If you are powering a big warehouse space, you will not just save hundreds of dollars a year, but potentially tens of thousands by installing solar, just in energy costs.

Then, there are also tax depreciation considerations. Depending on where your business is located, you can defray the cost of solar installation against your profit. Some districts will let you depreciate your solar panels over just one year, which is a huge boon to businesses that make a lot of money their first year.

Alternatively, you can depreciate your panels over five or ten years. That way, you spread out your tax advantage over a longer span of your business’s life. 

Wrapping up

As you can see, there are sound reasons for buying and leasing solar panels. Leasing solar panels has made solar energy available to more people than ever. And while buying is still the better long-term investment, leasing solar panels is a good alternative to buying for many people and in many circumstances. 

Ownership, however, delivers a tangible return on investment and energy resilience in the face of rising costs. Owning solar panels is the aspiration of anyone who want to live off grid and right now, has some great financial incentives. 

If you want solar panels, go for it! Whether you lease or buy, solar panels are a good overall idea. 

In this  Renogy Solar review, we’ll take a closer look at the brand, discuss what to look for when buying their products, and review some of their best solar kits.

The best 100-watt Renogy solar panel kits

Renogy solar panels are available in a range of sizes, sets, as well as kits. These include complete kits that contain everything you need to set up your solar system, except a battery.

Although you could run a solar system without a battery and simply draw power directly from the panel when the sun is shining, a battery will allow you to get the most out of the sun’s energy: learn more about batteries in this post on solar battery basics.

Here are some of the best options containing 100-watt solar panels, ranging from 100-watt to 800-watt output, and a mix of stand-alone panels as well as partial and complete kits.

1. Renogy 100W 12V Monocrystalline Solar Panel

This 100-watt solar panel from Renogy Solar is ideal for a range of off-grid uses, such as on campers, boats or RVs. Providing 100 watts of power, you could use this panel on its own if you have relatively modest needs, or use it to expand your existing setup.

The monocrystalline panel is made from advanced encapsulation material for high energy efficiency. This is great because you’ll get the maximum amount of power for the minimum footprint, so you won’t need to sacrifice too much roof space.

The power supply is regulated with built-in bypass diodes, so you won’t suffer power drops when the panel moves into the shade by bypassing the underperforming cells and allowing the solar panel to continue working. This is especially useful for RVs and boats, as these moving vehicles may often suddenly pass into shade, such as when you drive under a tree or a bridge.

The single solar panel is sold on its own, but comes with simple connections, making it easy to install and connect to your charge controller and battery (note you’ll need to buy these separately). 

The panel comes with pre-drilled holes for mounting, securing, and grounding, and is compatible with Z-brackets, pole mounts, and tilt mounts, though you’ll also need to buy the mounting accessories separately.

This makes this panel suitable for beginners, so you’ll be able to install it yourself, even if you don’t have any experience, as long as you have the correct equipment.

2. Renogy 100W 12V Monocrystalline Solar Panel (Compact Design)

This panel is very similar to the first Renogy solar panel on this list: it also gives up to 100 watts output, is made from highly efficient monocrystalline PV cells, and has built-in bypass diodes to avoid overheating and maximize output in partial shading.

Both panels also have a robust, corrosion-resistant aluminum frame, so will stand up to all kinds of weather, which is great because you can use the panel on your boat, RV, or camper for years or even decades without needing to replace it.

The key difference is the compact design: this panel is available in two sizes, 42.4 x 20 x 1.4 inches and 41.8 x 20.9 x 1.4 inches. This gives you maximum flexibility to choose the size that will best fit the space you have, so is perfect for tight spots such as boat and camper roofs.

Other than the size, the panels’ performance and specifications are identical. 

One panel will produce 400-500 Watt-hours or 33-41 Amp-hours, depending on the amount of sun. This is generally sufficient to power a small 12-volt fridge and to charge one or two devices. It’s also more than enough to use as a backup power source for your vehicle or boat battery.

3. Renogy 2-Pack 100 Watt 12 Volt Monocrystalline Solar Panels & Solar Panel Connector Assembly Tool

This kit contains two 100-watt compact Renogy solar panels, each measuring 42.2 x 19.5 x 1.4 inches. Combined, the two panels offer 200 watts of power, giving you plenty of power to charge your appliances or devices as well as providing backup power for your vehicle engine.

This makes this set ideal for anyone who wants to go off-grid for extended periods or travel in remote areas, as you can be confident you’ll always have power when needed and in emergency situations.

The advantage of buying two 100-watt panels rather than a single, larger-output panel is that you have more flexibility to fit the panels to the space available. You can also spread the weight across the roof of your RV or boat. 

This is useful because many vehicles can only support a certain amount of weight on each panel, and may only allow you to drill into the roof at certain points without compromising the structural integrity.

This kit includes two monocrystalline solar panels and a Renogy solar panel connector assembly tool, specifically designed for custom solar panel wires. 

This not only makes it easy to install the panels, but also break connections, which is great when you need to replace your panels or move them to another location.

4. Renogy 300 Watt 12 Volt Monocrystalline Solar RV Kit

This complete Renogy kit contains three monocrystalline Renogy solar panels with a combined maximum output of 300 watts, a 30A PWM LCD charge controller, adaptor kit, and all the connectors, cables, mounting brackets, and housing you’ll need to install the system.

With three 100-watt panels, this kit offers the same flexibility as the 200-watt set above with even more power. This makes it suitable for a range of uses, such as powering all the appliances in larger RVs, maintaining boat batteries, or off-grid structures such as campsites.

Being a complete kit, it’s excellent for anyone who wants to set up a completely new solar system. As all equipment is from Renogy, you can be confident that each component is well-made, durable, and compatible with the rest of the system.

5. Renogy 400 Watt 12 Volt Monocrystalline Solar Starter Kit w/ MPPT Charge Controller

This is another complete kit, this time with four 100-watt Renogy solar panels, delivering up to 1600Wh of output for power-hungry RVs, boats, and off-grid structures. Like the kit above, it also comes with a charge controller, adaptor kit, cables, connectors, and four sets of Z-mounting brackets, so you’ll have everything you need to set up your system (except for the battery).

The kit is compatible with lithium, lead-acid, or gel batteries, making it suitable for a range of setups. This is handy if you already have a battery that you want to use with your solar system, or have a particular preference.

Other than the additional panel to deliver 100 extra watts of output, the main difference to the 300-watt kit is the charge controller. This set comes with a 40-amp MPPT solar charge controller to handle the high power output, ensure optimum energy conversion, and protect the battery from discharge, short circuit, overcharge, or overvoltage.

The panels are made of high-efficient monocrystalline PV cells, are highly robust, and is easy to install, like the other products on this list, making this versatile kit ideal for a range of outdoor and off-grid uses.

6. Renogy 800W 12V/24V Monocrystalline Solar Premium Kit

This mammoth Renogy solar kit comes with eight 100-watt monocrystalline panels, making it a good choice for anyone who needs a lot of power. Depending on your power needs, you could use this set to power an off-grid cabin, run a large RV set-up, or maintain a large boat battery, as well as onboard appliances.

Of course, you’ll need enough space to mount eight solar panels, each measuring 41.8 x 20.9 x 1.4 inches, so it’s best suited to large rigs, larger boats, or permanent structures with weight-bearing roofs.

This complete kit includes eight 100-watt solar panels, a Rover60 charge controller, BT1 Bluetooth module, eight sets of Z-mounting brackets, solar branch connectors, cables, and two different types of fuses.

The powerful charge controller is rated for 60 amps of charging current to safeguard your system and the battery. Another feature that sets this kit apart is the Bluetooth module, which you can use to control the solar system from your phone from up to 82 feet away, making it easy to monitor your power usage.

This is very handy for troubleshooting any issues, as well as making sure you don’t discharge the battery too deeply, which can permanently damage the equipment and severely reduce its capacity.

Renogy solar buying guide

Now we’ve reviewed the best Renogy solar kits with 100-watt panels, let’s take a closer look at the brand, and what you need to know before buying their products.

Is Renogy solar any good?

Renogy is a reputable brand that offers well-made, robust and efficient solar panels with a number of features that you’ll struggle to find in cheaper models. Their charge controllers, adapters, and other solar equipment are also high-quality, with a range of products covering different amp rates, connections, and uses.

What we like:

What we don’t like:

Although not really designed to power an entire home, Renogy’s solar kits are an excellent mid-range choice for RVs, boats, and other off-grid uses. These are not premium products, nor are they the cheapest panels and solar equipment you’ll find on the market, but they offer a solid level of quality and an excellent number of features for the price.

Is a Renogy kit sufficient to power my home?

Most Renogy solar kits are designed for RVs, boats, camping, or small off-grid structures like cabins. Unless you have a tiny home, you’re unlikely to be able to completely meet your household energy needs with even the largest Renogy kit.

However, being comprehensive and easy to install, you could invest in a Renogy kit as an introduction to solar power, to complement the electricity your house uses from the grid. You could also use a Renogy kit to power dedicated devices or a section of your home, such as an outdoor area or deck.

However, the number of solar panels and power output your home needs can vary greatly depending on your needs, consumption, and how efficient your home is.

To learn about how to calculate your power needs and work out how many solar panels you need, take a look at our guide to solar panel energy output.

What to look for when buying a Renogy solar kit

Renogy offers a wide range of solar kits, with the main differentiators being the wattage (power output) and what is included with the kit.

If you’re trying to decide which kit is right for you, you first need to determine how much power you’ll need. If you only want backup power for your vehicle battery, or to charge a couple of devices, one or two 100-watt solar panels should suffice.

However, if you want to be able to power a number of different appliances or run your boat battery on solar, you’ll likely need between 400 and 800 watts of solar panels.

It’s also important to consider how much space you have available that is suitable to install solar panels. There’s no point buying a kit with three, four, or eight panels if your RV, boat, or cabin doesn’t have enough spots that can accommodate and take the weight of these panels.

Finally, be sure to check what is included in the kit: some kits come with the solar panels only, or a limited number of accessories, while others include everything you need to set your system, such as a charge controller, adaptor kit, connectors, cables, and mounting brackets.

It’s important to factor this in, as you may need to buy additional equipment before you can install your solar panels, and this will also affect your budget. Keep in mind that no Renogy kits include batteries, so you’ll always need to buy this separately.

Final thoughts on Renogy Solar review

Renogy is a well-known brand that produces well-made solar panels, and equipment for solar systems, and kits at a relatively affordable price point. This brand’s products are not the most premium option on the market, nor are they the cheapest: rather, they are a solid offering that represents good value for money.

With quality features like built-in bypass diodes and hot spot prevention, as well as multi-layered laminate coating and corrosion-resistant aluminum frames, you can be confident that the panels will perform well for years, if not decades. The manufacturer’s generous warranty also offers peace of mind in case anything does go awry.

These kits come in a diverse range of sizes and range from the panels only to complete kits. When buying a Renogy solar kit, it’s important to consider your power needs, the space you have available to mount your panels, and whether you need the panels only or a complete kit, in order to choose the best option for you.

For more on how to install a solar system in your home, RV, or boat, take a look at our guides to boat solar panels, flexible solar panels, and solar panel wiring. 

What is hydroelectric power?

Hydropower is any kind of usable energy that comes from water, which can be from a variety of sources, including turbines and dams. This is one of the most widely-used sources of renewable energy for electricity generation, and has been for years.

We most often see hydropower generated from reservoirs and dams, but it can also come from run-of-river, wave, and tidal power systems. For the purposes of this article, we’ll focus mostly on hydroelectric facilities rather than wave and tidal power, but all of these systems can be used to create consumable electricity to power homes and businesses.

Let’s take a closer look at the most common forms of hydroelectric power generation.

1. Conventional hydroelectric dams

A hydroelectric dam is the image most people have in mind when they think about hydropower, for good reason. This has long been the most common type of energy generation from water, with famous examples including the Hoover Dam.

Conventional hydroelectric dams have a large reservoir of water, which is why they’re often called storage or impoundment systems. Water pressure builds up behind the dam, and is designed to be released or held when needed to generate electricity, manage flow and water levels, or help with fish passage.

When the dam releases water from the reservoir, it flows through a turbine, making it turn, and as it does it activates a generator which produces electricity.

2. Pumped storage

Pumped storage hydropower, or PSH, functions rather like a battery for other power sources, such as solar, wind, or nuclear. The PSH system stores the energy generated from these other power sources, by pumping the water from a reservoir to another one at a higher elevation.

This energy can then be released when needed by letting the water flow back to the lower reservoir and turning a turbine as it does, generating electricity. This form of hydropower is most useful when used to fill the gaps during times of high demand.

3. Run-of-the-river

Run-of-the-river, also known as diversion facilities rely on a consistent supply of water coming from a lake, river, or reservoir. The system diverts a part of the water flow and sends it through a canal or penstock, taking advantage of the natural slope and flow of the river to turn a turbine and generate electricity.

This kind of system may or may not incorporate a dam, but the water flow is always regulated through a system of gates, valves, and turbines.

4. Tidal energy

Tidal energy, tide energy, or wave energy, relies solely on the rise and fall of the tide in the ocean. This is a clean, renewable form of energy, but can only be harvested in very specific locations, so is not viable for all countries and states.

Read more about tidal wave energy in our featured post.

Despite being driven by water, hydroelectric power plants actually produce electricity in a very similar way to coal power plants, making knowledge and technology easily transferable.

Both types of facilities rely on propeller-based turbines to generate power. While in hydroelectric plants the turbines are turned by water, steam turns the turbines in a coal power plant.

Pros of hydroelectric power

Hydroelectric power is a truly renewable type of energy, which doesn’t rely on a consumable feedstock, unlike biomass. This is just one of the advantages of using it to generate electricity, which we’ll look at next.

1. It’s a clean, renewable source of energy

Hydropower is a cleaner, renewable alternative to fossil fuels. Much of the world still relies on coal and natural gas to power their homes, but these sources of energy won’t last forever, with scientists predicting known reserves of both will run out this century at our current rate of use.

Water, on the other hand, is a renewable source of energy: as long as it continues to flow, we’ll be able to use it to generate energy, without using up the water itself.

Furthermore, fossil fuels generate greenhouse gas emissions as well as other forms of pollution. It should be acknowledged that hydroelectric facilities usually involve fossil fuels and other environmental impacts to build, but once constructed, they don’t cause water or air pollution.

2. Low installation and operating costs

Despite a significant initial investment, hydroelectric power is one of the lowest-cost types of renewable energy over the long term.

After building the infrastructure, very little maintenance is needed over time and running costs are much more affordable than other types of electricity generation. The return on the investment lasts for a long time, with hydroelectric dams and power plants easily lasting more than a century.

Furthermore, hydropower technology is continuously being developed and advanced, becoming ever more efficient and cost-effective.

3. It uses simple, understandable technology

Another advantage of hydroelectric systems is that as well as being affordable to run, they’re also relatively simple. For this reason, facilities are being built and successfully run in countries all over the world.

Furthermore, because hydropower plants operate in a very similar way to coal power plants, as coal is phased out, it will be relatively easy for workers to transition to the hydro industry.

4. It’s flexible

Hydro energy can easily be turned on and off to meet demand or as river flows change, with a limited operating expense. It’s also possible to shut off the system without affecting its overall performance.

Equally, hydroelectric power facilities can be ramped up very quickly once flows are at peak levels or to supplement other sources of energy and typically have high capacities.

5. It can be used with other renewables

Hydroelectric is also ideal for pairing with other forms of renewable energy. Because most hydropower facilities incorporate reservoirs that store large bodies of water, they can provide a stable source of energy to supplement less reliable renewables such as wind or solar.

Furthermore, most hydroelectric facilities are designed to gear up from zero to maximum power output virtually instantly, unlike many other types of electricity generation. Therefore, they can immediately feed power into the grid when required and cover power disruptions or outtages.

In other words, hydropower can fill in the gaps when the sun doesn’t shine or there isn’t enough wind to generate enough power. This helps to address one of the most common concerns around renewable energy.

6. It’s made in the USA

Many types of electricity generation technology, both renewable and non-renewable, come from overseas. However, hydroelectric power is made entirely in the USA, supporting local jobs, particularly in rural communities, and minimizing the emissions associated with transporting the tools and infrastructure.

Currently, the hydropower industry in the USA employs more than 66,000 people and the growing industry is predicted to expand to 120,000 jobs by 2030, not only in direct hydroelectric generation, but also manufacturing, construction, transportation, water management, environmental science, and professional services.

Furthermore, the water itself comes from domestic sources, so every state can generate its own power that doesn’t rely on international sources of fuel.

7. Hydropower facilities support other uses

Hydropower facilities can serve multiple purposes: not only can they harvest the power of water and convert into energy, but they can also supply water for irrigation. With water shortages and drought on the rise in many areas, this can be a very useful way to supply vital water to crops or drinking water to local towns.

In some cases, hydropower systems can assist with flood control, and so play a vital role in protecting humans and animals alike.

Hydropower reservoirs can also provide recreational opportunities to local communities, such as boating, fishing, and swimming. In fact, local authorities usually require hydroelectric companies to allow the public to access and enjoy the reservoir.

Cons of hydroelectric power

Despite its benefits, hydroelectric power also has its downsides. It’s important to be aware of these considerations when balancing the advantages of this kind of renewable energy.

1. It can have negative environmental impacts

While hydropower is a generally clean, renewable source of energy, this doesn’t mean it’s always good for the environment.

Most hydroelectric facilities rely on storage hydropower or pumped storage hydropower systems, that is, reservoirs made by dykes or dams. These are formed by disrupting natural river systems that can disturb wildlife, destroy habitats, and threaten water quality.

However, there are other forms of hydropower that have a lower environmental impact, notably run-of-river, wave, and tidal power systems, though these are currently the minority of hydroelectric plants.

2. It can impact on people too

Damming rivers and creating reservoirs can have negative impacts not only on wildlife and their habitats, but also humans. People may be forced to leave their homes to make way for hydroelectric systems, and this most commonly affects rural and indigenous communities.

Despite the compensation usually offered, this can have incredible impacts on not only the individuals involved, but also local cultures going back generations.

In some countries, people may even be forced to move under threat of violence. In 1982, 444 Mayans, mostly women and children, were reportedly killed because they refused to move to make way for the Chixoy dam.

Furthermore, it’s not just the communities who live in projected reservoir areas that can be disrupted. Hydroelectric facilities can increase the risk of flooding downstream, potentially putting people living in these areas at risk.

3. Large upfront investment

Although being cheap to run once established, building a hydropower plant is a huge, costly project. Establishing a hydroelectricity facility involves not only building power-generating turbines and their associated power plant, but also other infrastructure such as a dam and reservoir in the case of storage hydropower.

Furthermore, the cost of building such facilities is only set to increase in the future as suitable sites are used and therefore becoming more scarce.

4. Risk of large-scale failure

All dams involve risks such as construction accidents, dam failure, and flooding. Storage hydropower facilities can have huge volumes of water in their reservoirs, which could cause devastating destruction if things go wrong.

At least 96 people died as part of building the Hoover Dam, and when the China’s Banqiao Reservoir Dam was destroyed in a typhoon in 1975, it failed causing the deaths of more than 150,000 people.

Although modern dams are built to much higher safety standards and well-maintained to make them as safe as possible, some risks still remain.

5. Water is becoming increasingly scarce

Although water is a renewable resource, there are concerns over its supply. Globally, we’re seeing a downturn in the amount of water available.

If rainfall drops enough and droughts become severe, low water flows could make hydroelectric facilities less efficient and could even stop being viable entirely.

Furthermore, running a hydroelectric facility usually involves some degree of water loss. Although this is a very small proportion of the overall water used, it’s important to consider this loss given the global water crisis.

6. There are limited sites for storage hydroelectric facilities

While water is largely unlimited, there is a limit on the locations suitable for hydroelectric facilities, or more specifically, storage hydro plants with reservoir dams. Hydroelectric dams have very specific requirements and can only be built on certain sites.

It’s important to find a location that can not only support a hydroelectric dam, but will also turn enough profit to justify the investment to build the facility.

Final thoughts

The pros and cons of hydroelectric power paint a complex picture. This is a clean, renewable, and largely environmentally-friendly way to generate electricity, but it can also have negative impacts on people and the planet.

As we look to move away from non-renewable, polluting, and dangerous fossil fuels like coal and natural gas, it’s important to take a considered view of the alternatives. By acknowledging the drawbacks and managing the risks associated with hydropower, we can come up with the best solutions for the future.

Hydropower facilities from an investment standpoint as they are straightforward, proven and relatively predictable. Perhaps the answer lies in using hydroelectric power plants in coordination with other renewables like wind and solar.

Learn more about the future of renewable energy with our guides to solar, wind, geothermal, and biomass. Or check out our post about the pros and cons of sea wall.

One solution that’s gaining traction is using household waste as an energy source. Though the idea of processing waste to generate heat or electricity is not new, waste-to-energy technology is an effective way of keeping waste out of landfill while creating a renewable source of power for communities. In this article we’ll cover:

• What waste-to-energy is and how it works.
• The technologies involved in waste-to-energy.
• Global adoption of waste-to-energy and why uptake is low in the US.
• Discuss if waste-to-energy is as good as it sounds.

So what is ‘waste-to-energy’ and what does it mean?

According to the World Energy Council, waste-to-energy (WtE) is a term given to a range of waste treatment processes that can generate energy. The energy generated by WtE can be electricity, steam, heat, or fuels like diesel, literally converting trash into energy for powering homes and communities.

Depending on the type of waste treatment process, WtE uses waste sources that include:

• Solid refuse called municipal solid waste (MSW)
• Semi-solid effluents from industry
• Liquids like domestic sewage 
• Gases like refinery exhaust fumes

WtE is a key solution for municipal solid waste management

With over 2 billion tons of waste heading to landfill every year, it’s easy to see why MSW is the most common source of waste for WtE. 

The processing of municipal waste by incineration in a combined heat and power plant (CHP) is the most common example of WtE in action and integrates seamlessly into solid waste management processes across much of the developed world. 

Generating energy from waste is not a new thing 

People have used their refuse to generate energy since pre-industrial times. Early examples of generating energy from garbage included burning of waste paper for heat and cooking or used cooking oil as lamp fuel. 

In 19th century England, they burned solid waste on an industrial scale to provide steam that was used to generate electricity. Another early example of getting energy from waste is the refuse-derived fuel (RDF) produced in Japan at the start of the 20th century. 

The benefits of WtE are tangible

WtE is attractive because it uses negative-value waste to produce valuable energy, bypassing the cost and pollution of using non-renewable energy sources like oil and gas. 

Rather than looking the other way and just dumping our trash, we can put it to good use as fuel for heating and lighting our homes. 

Other great benefits of WtE include: 

• Reducing the landfill burden. Landfill is the most common method of disposing of MSW. But it’s highly polluting as it generates greenhouse gases and leaches hazardous substances into the earth. WtE reduces landfill use as it diverts waste from the landfill to be used for energy.  

• Generating clean energy. WtE often involves burning waste, but, unlike gas, consumers can use the electricity, steam, and hot water produced with no further emission of greenhouse gasses. 

• Provision of baseload power. A WtE plant can provide power 24 hours per day just like a regular power plant, continuously adding valuable electricity to the grid.

• Reducing methane. As your trash rots in the ground, it releases methane, a notable greenhouse gas. By diverting waste from the landfill, WtE reduces the levels of methane emission as it is no longer being generated. 

• Recycling metals. The incinerated refuse usually contains large quantities of metal that is recovered for recycling after the plant has incinerated the waste.

How does the waste-to-energy process work?

Waste-to-energy is comprised of several established and emerging technologies that all have the benefit of generating energy as a byproduct of waste processing. At the most basic level, WtE revolves around diverting municipal solid waste (household trash) from the landfill to the WtE plant.

From this point there are three main technologies:

• burning the waste and using the heat to boil water and turn a steam turbine,
• converting the waste to synthetic gas as fuel for electric generators,
• processing the synthetic gas into fuel for vehicles or planes.

This video by Covanta, a leading waste-to-energy company explains the process:

Established and emerging WtE technologies

Waste-to-energy plants use a range of methods to extract energy from refuse. Here are  six of the leading WtE technologies being developed and used around the world: 

1. Combined Heat and Power (CHP) incineration

This is the most developed of the WtE technologies with over 2000 plants worldwide. These plants burn MSW to heat water, creating steam to turn a turbine and generate electricity. 

2. Co-combustion

This form of CHP incineration burns clean coal or biomass alongside mixed waste. Adding fuel makes it easier to control the combustion process to get more efficient energy generation. Co-combustion can offset the cost and emission of coal-generated power. 

3. Thermo-chemical conversion

Thermo-chemical conversion is a process that is being developed to limit the harmful combustion gases that are produced by conventional CHP incineration. It involves extraction of the energy content of the waste using thermal treatments rather than frank combustion. 

4. Refuse-derived fuel (RDF)

RDF is an efficient way of generating fuel from various waste fractions separated using techniques like air classification and ballistic separation. Materials like recovered paper, cardboard, and certain plastics undergo processing into pellets for burning. 

5. Thermal gasification

This is a relatively immature technology that has the promise of converting the carbon content of waste into a combustible gas. 

6. Biochemical conversion 

Biochemical processes, including the use of microorganisms, can be used for accelerated decomposition of the waste, producing solid, liquid or gaseous fuels. An example of this is the production of bio-ethanol from fractionated waste. 

Just how efficient is WtE?

Waste-to-energy has the potential to not only transform waste management but also contribute significantly to sustainable energy production, but the efficiency and energy yields of these processes will determine whether WtE is viable for more widespread adoption. 

The World Energy Council reports that CHP facilities currently have a maximum efficiency of 35%. This efficiency rating varies according to the size of the plant, the type of waste it processes, and the power output it achieves.

The Netherlands is home to the largest CHP incineration plant in the world. The Afval Energie Bedrijf CHP plant in Amsterdam which has a capacity of 114.2 MW of electricity generation. 

This massive WtE plant processes 1.5 million tons of trash each year with an efficiency of 30%. For comparison, according to the US Office of Fossil Energy and Carbon Management, the average coal-fired power plant in the US has an efficiency of 33%, so WtE is not doing too badly. 

Why is Sweden practicing waste-to-energy, but not the US?

Though waste-to-energy plants are all over the world, certain countries have embraced this form of renewable energy generation. Sweden is renowned for its national recycling strategy that takes 99% of the nation’s trash and either recycles it or burns it for domestic energy consumption. 

This radical approach has transformed trash into treasure with waste becoming a valuable commodity that is even imported into the country generating over $100 million annually.

With virtually “zero trash heading to landfill”, Sweden’s 34 WtE power plants incinerate everything that cannot be reused to provide electricity for at least 250,000 homes and businesses. This works out at about 50% of all waste, compared to 40% in the United Kingdom and just 12% in the United States.

Waste-to-energy adoption in the US is low, but the tide is turning

The United States has one of the lowest rates of waste-to-energy adoption in the developed world. Despite this, the US still incinerates about 30 million tons of trash to generate electricity for homes each year.

As one of the largest oil producers in the world, it’s easy to see why America hasn’t yet embraced WtE. Because the US is such a major fossil fuels producer, the costs of using oil and gas are much lower than in areas that rely on imports, like Sweden. 

As of 2021, the US was consuming over 16 million barrels of oil daily and 30.28 trillion cubic feet (Tcf) of natural gas annually. The US’s expansive proved reserves of fossil fuels are expansive but finite, and eventually other sources of energy will have to become prominent as reserves decline.

The US also has cheap and readily available landfill space 

Sweden has another motivation lacking in the US; no room for major landfill operations. Whereas the US has an abundance of cheap, wide-open land. In 2018, the US landfilled over 146 million tons of waste, the vast majority being food. In contrast, only 4.6 million tonnes of waste is landfilled in Sweden annually, less than 1% of the MSW generated.

Political pressure favors oil and gas

Lobbying and other political pressure from the oil and gas industry may have influenced the expansion of WtE as it could compete with the dominance of oil for energy production. However, for cities like New York which has to export 14 million tons of trash annually, the waste management benefits of WtE are becoming hard to ignore.

WtE is an international effort 

Sweden is well known for its WtE efforts, but other countries including Denmark, Germany, Japan, and China around the world are also adopting WtE technologies. 

Are waste-to-energy practices better for the environment?

This is the big question. After all, current WtE practices largely involve the incineration of waste which is an energy-intensive and costly process. Here are some disadvantages of WtE: 

Environmental impact

Trash is dirty stuff and burning it on a large scale causes air pollution, releasing the very same greenhouse gases it seeks to mitigate. Right now, incineration is an unavoidable part of WtE. Still, there is evidence that overall, WtE strategies reduce carbon dioxide emission with every ton of processed garbage preventing the emission of a ton of CO₂.

Public health

The residual ash remaining from waste incineration contains cancer-causing heavy metals and dioxins that are released into the atmosphere. As recently as 2018, Ana Baptista, Assistant Professor of Environmental Policy and Sustainability Management at The New School, stated that NYC’s WtE facilities were producing up to 14 times the mercury, twice as much lead, and four times as much cadmium per unit of energy compared to coal power plants. 

Infrastructure costs

Getting energy from waste is expensive and the infrastructure for building and operating a single WtE plant can run into hundreds of millions of dollars. According to waste-to-energy International, a company that builds CHP plants, the development costs for a new plant are approximately $680 to $1,026 per ton of waste processed annually. 

What does the future look like for waste-to-energy?

Waste-to-energy remains controversial but, despite the pollution, it provides a practical, sustainable solution, to the problem of skyrocketing garbage. WtE industry experts are continually developing technologies that can make WtE cleaner and more efficient.

As urbanized populations continue to grow, the refuse they generate could provide the same populations with clean, sustainable energy while reducing the landfill burden. State-of-the-art WtE facilities are likely to be developed that can recover as much energy as possible from diverse solid waste sources while mitigating the effects of exhaust gases by cleaning and filtering them for maximum environmental benefit.

What is nuclear energy?

Before we discuss the pros and cons of nuclear energy, it’s important to get clear on what it is we are actually talking about – with a clear definition and explanation. 

All matter on earth is made up of tiny particles called atoms, composed of even small particles called protons, neutrons, and electrons.

The positively-charged protons and neutral neutrons make up the center, or nucleus of the atom, with the negatively-charged electrons forming a cloud around it. The bonds between the protons and neutrons help to hold the nucleus together.

These bonds contain massive amounts of energy which is released if they break down. This process, of breaking apart the nucleus of an atom by destroying these bonds is known as fission, nuclear fission.

This is where nuclear energy comes from, so named because the energy is produced by breaking down the nucleus of an atom.

In this process, the energy released through the fission reaction serves as a source of heat. In a nuclear power plant, the heat is usually used to turn water into steam which turns turbines, producing electricity.

The most common fuel used in nuclear power plants today is uranium, or U-235. In the nuclear fission reaction, a collides with a uranium atom, splitting it.

Along with releasing energy in the form of heat, when the uranium atom splits, it also releases a neutron from its nucleus, which collides with another uranium atom nearby. This repeats over and over in a self-sustaining chain reaction.

Currently, 28 US states have at least one commercial nuclear reactor, with a total of 93 operating reactors at 55 facilities across the country. Combined, these reactors can generate up to 95,492 MW of electricity – to put this in context, 1 megawatt can power the average US home for 1.2 months.

Advantages and disadvantages of nuclear energy

Nuclear energy has incredible potential to replace fossil fuels in order to power our homes, businesses, and industry, without the greenhouse gas emissions and much of the pollution associated with coal, oil, and gas. 

However, there are some serious concerns associated with nuclear power, so it’s important to understand both the benefits and drawbacks of this type of energy.

Benefits of nuclear energy

We’ll start by looking at the benefits of nuclear energy and why this type of fuel has many advantages over fossil fuels in particular.

1. Nuclear energy is largely sustainable

Commercial nuclear reactors commonly use uranium as fuel, an element which exists in abundant quantities across the world. Unlike fossil fuels, the world has plenty of uranium resources – the world has over six million tons of known recoverable uranium, which is predicted to last anywhere from 80 to 230 years based on our current rate of consumption.

Additionally, the World Nuclear Association argues that there are many more sources of ‘unconventional resources’ which can be used to produce uranium using other metals.

Although uranium is not a renewable resource as sources are finite, technology is rapidly advancing to allow us to recycle fuel over and over.

Countries such as Japan and France are developing ways to efficiently recycle reactor fuel, which would mean that spent nuclear fuel can be reused. Being able to reuse nuclear fuel again and again would make this a semi-renewable source of energy.

Furthermore, nuclear reactors produce almost no pollution and only minimal amounts of carbon emissions – the main by-product of the nuclear fission process is steam.

It should be noted that there are concerns over excessive water use of nuclear facilities, but we’ll cover this later, in the cons section of this post.

2. Nuclear energy is highly efficient

The nuclear fission reaction produces high-density energy, making uranium much more efficient as a fuel than coal, natural gas, and other fossil fuels. With nuclear energy, much less fuel is needed to produce the same amount of energy.

Furthermore, because this highly-efficient fuel can generate constant energy for an extended period of time, reactors don’t need to be refueled very often which avoids frequent shutdowns. As the technology develops, nuclear power plants are becoming even more efficient, meaning we can generate even more energy from the same fuel.

3. Very limited greenhouse gas emissions

Unlike burning fossil fuels, the nuclear fission process does not generate CO2 or any other greenhouse gasses – only steam. Much of this steam is condensed back to water and returned to the system through the iconic cooling towers which are key features of nuclear power plants.

In this way, much of the water is recycled, minimizing the use of water.

The process in the nuclear reactor can emit negligible amounts of CO2, for example by using backup generators during refueling or by running the plant on idle, but these emissions are usually minimal. A nuclear reactor emits a fraction of the carbon emissions of a conventional power plant during its lifecycle, which can be up to 70 years, compared to around 30 years for coal power stations.

4. Maintenance costs are low

Nuclear power plants can run for years with very little maintenance and minimal refueling, making them very cost-effective to maintain. The overall running costs of a nuclear power plant are much lower than coal, natural gas, and kerosene-based facilities.

The average nuclear power plant can run for more than 60 years without needing to be shut down for maintenance. Generally, only the reactor’s core needs some degree of regular maintenance, but even this is only necessary occasionally.

This also means low costs to the environment: because nuclear reactors can continue to run for decades with minimal maintenance, we don’t need to build new power plants so often. This minimizes the resources needed in new builds and the environmental impacts associated with construction.

Disadvantages of nuclear energy

Now we’ve discussed the benefits of nuclear energy, let’s take a look at the drawbacks that need to be considered.

1. Radioactive materials can be harmful to the environment

Nuclear energy relies on uranium, which is a highly radioactive material. Spent uranium fuel remains radioactive for centuries, and during this time is devastating to the environment, if not disposed of properly.

In the event that it isn’t disposed of correctly, nuclear waste can contaminate water, soil, and air, harming all kinds of life and potentially making the environment inhabitable.

Equally an accident, from a leak from the plant to complete meltdown, can severely damage the environment up to hundreds of miles away.

Therefore, it’s extremely important to factor in the cost of properly handling nuclear material and ensure that it is managed properly to avoid damaging the environment. This is crucial if nuclear energy is ever going to be considered as a viable alternative form of energy. 

2. There are safety risks associated with nuclear energy

For the same reason, nuclear power plants and their waste can pose severe risks to human health. If people are exposed to nuclear radiation, they can suffer a range of long-term health effects, including increased risk of developing a wide range of cancers.

Large doses of radiation can be fatal in the short term: exposure to very high levels of radiation causes acute radiation syndrome, which induces vomiting and nausea within hours and can result in death within days or weeks.

There are also proliferation issues associated with nuclear power. Enriched uranium can be used to make devastating nuclear bombs, so it’s essential that uranium doesn’t fall into the wrong hands.

This is one of the major concerns as more countries start to use nuclear energy, but essentially comes down to good management, as responsible authorities need to monitor fuel use to avoid proliferation.

3. Nuclear energy is high cost

Although ongoing maintenance is relatively inexpensive, building a nuclear reactor in the first place involves a large investment of capital. So in essence, the outlay cost is large, but ongoing costs are minimal.

Additionally, stored uranium fuel as well as spent fuel rods require careful handling and expert attention, which can also involve significant costs. Similarly, nuclear power plants require tight (and therefore expensive) security to manage the risks of proliferation of these hazardous and potentially dangerous materials.

Is nuclear energy really renewable?

A deeper analysis of the pros and cons of nuclear energy is needed to explore this topic further, the first question being whether nuclear energy is really renewable.

The answer to this is not a simple yes or no. The world has extensive uranium reserves, which we have only exploited a small percentage so far. Furthermore, because uranium is such an efficient fuel for nuclear energy, we only need to use smaller quantities of fuel to produce the same amount of power.

However, this is not the same as being a renewable source of energy. Uranium is a naturally occurring element that was formed over millions of years, and once we use all the earth’s reserves, we cannot generate any more.

In contrast, truly renewable sources of energy, such as solar, wind, and hydro energy are truly unlimited: we’ll be able to tap into these sources forever without them ever running out.

Having said that, scientists are currently developing technology that would allow us to recycle used nuclear fuel. This would involve using breeder reactors to turn the used uranium isotope into plutonium, a more potent fuel that can generate 60 times more energy from the same raw materials.

Not only would this allow us to make use of the increased potential of spent fuel, which is able to produce 30-50% more energy than natural uranium, but it also means that we’ll be able to reuse the same fuel multiple times. In this way, nuclear energy would be a semi-renewable source of energy.

How much pollution does nuclear energy produce?

Nuclear power plants create a fraction of the pollution and waste generated by fossil fuel-run facilities. For example, coal power plants produce pollutants such as toxic carbon monoxide, mercury, and lead, as well as causing acid rain.

Perhaps most seriously of all, the use of fossil fuels produces greenhouse gasses, the main cause of global warming. If we continue to generate emissions at our current rate, experts predict a rise in global temperatures of up to 3.4 degrees Celsius by 2100 and with it, severe drought, habitat destruction and natural disasters on a scale we’ve never seen before, all of which could threaten life on earth, including humankind.

In contrast, nuclear fission produces only negligible amounts of greenhouse gasses: the main waste product of the process is steam, along with comparatively small amounts of spent uranium. This waste is the major drawback of nuclear energy: it is difficult and extremely expensive to dispose of responsibly, and failure to do so can have devastating impacts on people, animals, and the natural environment.

However, scientists are currently working on solutions to be able to reuse this waste as potent nuclear fuel, which would make nuclear energy even more efficient and minimize the nuclear waste issue.

Is nuclear energy a clean energy source?

One of the major benefits of nuclear energy is that it can act as an alternative to fossil fuels to create power with minimal greenhouse gas emissions. Equally, it doesn’t produce the air pollution associated with power plants running on fossil fuels, most notably coal.

Today’s uranium producers are highly responsible – the same can’t be said for many of the countries which supply oil, coal, and gas. In contrast, the uranium sector is known for being responsible, thorough, and safety-conscious.

However, the process involves radioactive fuels which leave behind dangerous waste that can have severe impacts on human health as well as the environment if not handled properly. For this reason, it can’t really be considered a 100% clean source of energy.

Another environmental concern around nuclear energy is water use: nuclear power plants use huge volumes of water to cool their reactors, which produce high amounts of heat and can be extremely dangerous if not cooled properly. As water scarcity becomes an increasingly serious problem globally, this water use may contribute to droughts, deforestation, and even conflicts.

However, many nuclear facilities work hard to recycle the water used in the system, keeping water use as low as possible. There’s even the potential to use the heat generated by nuclear reactors to desalinate seawater as a way to produce more clean water without using fossil fuels or creating greenhouse emissions.

Therefore, although the radioactive nature of nuclear fuel and waste means this is not a truly clean energy source, if handled responsibly it is certainly much better for the environment than fossil fuel alternatives.

Pros and cons of nuclear energy Do the former outweigh the latter?

There are many pros and cons of nuclear energy. This energy has many benefits that put it ahead of fossil fuels: it’s highly efficient, low-maintenance, comparatively clean, and generates only negligible amounts of greenhouse gasses.

However, there are a couple of very significant drawbacks that we shouldn’t overlook: most notably, the environmental and safety risks associated with nuclear fuel and its waste, as well as the excessive amounts of water needed for nuclear fission.

A lot of this comes down to responsible management: from mining and energy production to waste disposal, it’s essential that authorities handle radioactive materials properly and securely, as well as prevent accidents, leaks, meltdowns, and proliferation.

As long as we handle radioactive materials and nuclear waste properly, as well as continuing to develop technologies to make the process more efficient, reuse spent fuel, and minimize water use, nuclear energy has the potential to be an efficient, effective, and mostly clean source of energy.

If you’re interested in learning more about different types of energy, take a look at our post on five major types of renewable energy.