Clean, Green, and Renewable Energy: What’s the Difference?

A dam providing power.

The following article was written by originally published on the Dogwood Alliance blog.

You’re probably familiar with the terms clean energy, green energy, and renewable energy from the news. You may even think that they mean roughly the same thing.

I’m sorry to say that’s not the case. (It’s ok, you’re not alone in that.)

It turns out that each of the three terms differ from one another and have their own specific meaning. They all sound like they’re good for the environment. Some of them are better for the environment than others. These differences are vitally important if we’re going to save the environment and tackle the mounting climate change problems we’re facing. So keep reading as we explore each type of alternative energy to fossil fuels.

What is clean energy?

Clean energy is simply any energy source that doesn’t pollute and release greenhouse gasses like carbon dioxide, methane, or nitrogen monoxide. Clean energy sources are great long-term replacements for fossil fuels because they keep greenhouse gas emissions to minimum levels and don’t pollute the environment around them.

CAN YOU THINK OF ANY ENERGY SOURCES THAT ARE CLEAN?

If you said solar power, wind power, wind turbines, or hydroelectric power (as long as it doesn’t pollute) then you’re correct! Have you ever heard of geothermal energy? Geothermal energy is heat energy taken right from the Earth. The earth’s heat is used to boil water and create steam, which is then used to generate electricity. Think of a coal power plant that runs on the Earth’s natural heat!

In contrast, biomass energy is not a clean energy source. This is because, unlike wind power, biomass energy produces a lot of air pollutants and greenhouse gases. It also doesn’t rate very high in energy efficiency.

What is green energy?

Green energy is any type of energy that comes from a natural source. This means that solar energy, wind energy, and hydro energy are all examples of green energy. The Environmental Protection Agency (EPA) describes green energy sources like wind energy as providing the highest environmental benefit. Like renewable energy (which you’ll read about next), green energy is a great solution towards achieving greater sustainability in our power grid.

And lastly, what is renewable energy?

Renewable energy is any type of energy that comes from natural sources and replenishes itself. Believe it or not, people have already been using renewable energy resources for hundreds of years.  Wind farms for generating electricity and transforming the wind into wind power. This renewable electricity is helping us decrease our green house gas emissions.

CAN YOU THINK OF ANY TYPES OF ENERGY THAT WOULD BE CLASSIFIED AS RENEWABLE?

Once again, if you said solar energy or wind energy, then you’re correct! Before cheap and dirty alternatives were available like coal, gas, and oil, people would heat themselves with renewable sources like the sun. Now we use solar panels and wind turbines to harvest the power of Earth’s renewable energy sources.

So what’s the difference between them?

Did you notice there are similarities and significant overlaps among the three types of energy? In fact, the terms are so similar that they’re often used interchangeably everyday even by environmentalists! But there exist small but important differences. These differences are related to their creation, their renewal, and their impact.

CREATION

Renewable energy generates electricity from natural sources. These sources can be replaced completely within a generation. If you’re thinking fossil fuels and natural gas are natural sources, then you’d be correct. However, they take millions of years to replenish, so they’re not renewable energy sources.

Green energy is a subset of renewable energy. It must come from natural sources, but it can’t pollute the environment. Like green energy, clean energy doesn’t (or nearly doesn’t) pollute, but it doesn’t need to come from renewable energy sources.

RENEWAL

As the name implies, renewable energy is renewable! It doesn’t run out and is naturally restored. As a subset of renewable energy, green energy is also renewable, in addition to not having a negative impact on the environment.

Clean energy, though, is separate. Like green energy it doesn’t pollute, but it doesn’t have to come from renewable energy sources. Some consider nuclear energy a clean form of energy that isn’t renewable energy. However, the waste water nuclear energy produces is potentially a pollutant to the surrounding environment, so saying that nuclear is clean energy is a questionable claim.

IMPACT

Lastly, some renewable energy sources can have an environmental impact. For example, the creation of a hydroelectric dam can have harmful or even devastating impacts on its immediate environment and local fauna, while providing renewable energy. Both clean energy and green have no (or negligible) environmental impacts.

Is there a perfect combination?

Energy can fall under one, two, or even three of the categories at the same time. Take solar energy and wind energy for example. These two types of energy are clean (they do not release greenhouse gasses or polluting chemicals), green (they come from natural sources), and renewable (they replenish themselves).

This makes energy sources like wind and solar ideal because they renew themselves and produce electricity and power. They do this in a sustainable way that doesn’t contribute to climate change and is a better solution for generations to come.

In Conclusion

Now you know the similarities and differences between clean, green, and renewable energy. They’re all important improvements upon burning fossil fuels for energy production. Some are better than others, but conversion to any of the three is a step in the right direction towards combatting and countering the effects of climate change. Remember, ideal combinations of the three exists, such as solar power or wind energies, but one or two out of the three isn’t bad either!

Nataly Perez Manrique is a Latin immigrant from Peru. She has a master’s degree in Environmental Engineering from Duke University. She is also an advocate for the eradication of violence against women and the defense of Indigenous peoples’ rights in her home country.