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Clean Energy Explained: What Is Renewable Energy vs. “Green” Energy?

While green energy often comes from renewable sources, not all renewable sources can be considered green.
Wind turbines in a large green field.

For decades, optimistic environmentalists and scientists have dreamed of a world powered by 100% renewable energy—a goal that’s become increasingly important in recent years alongside an ever-growing concern over the health of our planet.

We’re now in the midst of a historic push toward alternative energy sources, particularly those that are renewable and sustainable, to combat the harmful environmental impact of fossil fuels.

Debate continues as to whether a 100% renewable energy future is feasible, but much of the world agrees about the need for deep decarbonization.

Nations, cities, governments, corporations and organizations alike are setting aggressive emissions-reduction goals—typically 80%-100% over the coming decades—in a collective effort to limit global warming to 1.5°C by mid-century, as put forth in the Paris Climate Agreement. With this need for decarbonization comes a need for greater electrification, but where will this energy come from and how sustainable will it be?

To understand its potential, we must first understand what exactly renewable energy is, and how does that differ from “green” energy?

A massive solar panel array in a field with the sun beating down on it.

What is renewable energy?

Renewable energy is a form of clean energy. The terms are often used interchangeably, as “clean energy” represents any sort of zero-emissions energy source that doesn’t pollute the atmosphere.

But to define it more specifically, renewable energy is energy that comes from natural sources that are constantly replenished, and thus they will never run out or become depleted. At its core, renewable energy is a clean energy that relies completely on the planet’s natural mechanisms and resources. Wind power, solar power, geothermal energy, hydropower, tidal power, biomass fuel—these are all examples of renewable energy.

Wind and solar are renewable energy resources

Wind power works as long as the wind is blowing, which spins turbines to produce electricity. And as long as the sun is shining, solar power can be produced.

Looking at the wind and the sun, it’s easy to see that they are naturally and perpetually renewable. The wind is always going to blow and the sun is always going to shine. Though their intermittentness—that is, the wind isn’t always blowing nor is the sun shining 24/7—does create the need for better energy storage solutions which can deploy energy at times when it’s not actively being produced. The good news is that increased research and technological solutions have already led to massive strides in storage capabilities.

Fossil fuels are not renewable energy resources

Traditional energy sources on the other hand—such as fossil fuels comprising of coal, oil, and gas—exist in a finite supply and are not renewable (or replenishable) enough on a human timeline that makes them perpetually viable for us.

The other big problem with fossil fuels is that they release carbon into the atmosphere when they’re burned for energy. This is typically in the form of carbon dioxide (CO2) and methane, two of the most harmful greenhouse gases that are having a detrimental impact on our environment and helping to accelerate climate change.

Renewable energy sources either don't emit any carbon or are carbon neutral (absorbing as much carbon as they admit). This makes them a far better choice for our environment, our personal health, and for doing our part to slow down climate change.

Why is renewable energy important?

Renewable energy isn’t just important, it’s absolutely vital for the health of our planet, the health of people, and for the future of energy use.

Despite the growing popularity of renewable energy, most places around the world are still relying on coal, oil, and natural gas as their predominant energy sources—contributing to unsustainable levels of CO2 and methane into the atmosphere.

This is why renewable energy sources are becoming incredibly important as our societies and economies progress. Climate change will continue to have a detrimental impact on millions, if not billions of people around the world.

As a finite resource that's harmful for the environment, it only makes sense for us to shift away from fossil fuel reliance and more toward renewable energy sources.

But historically, fossil fuels have been much cheaper to produce than renewable resources (from building and maintaining the infrastructure to operating the plants and turning the fuels into energy). Decision makers had no monetary incentive to invest in, or accelerate, the reliance on renewable resources.

Today, however, renewable energy sources such as wind and solar are becoming cheaper than fossil fuels. Solar is now consistently cheaper than coal and gas power plants in most countries thanks to increased demand, growing support from governments and corporations, and better technology. In some markets, the total cost of building and running new solar and wind plants has even decreased below the cost of running already existing coal plants.

Cost reduction and mass adoption go hand-in-hand to accelerate the transition to renewables and ensure our planet has enough energy for the future.

The costs for renewable energy resources should continue to drop, making them more viable for both residential and commercial use. Renewables can help keep energy prices at affordable levels, create jobs for local communities, prevent power shortages—and they’re great for the health of people as well as the environment.

Renewable energy also helps nations with improved energy security, reducing reliance on fossil fuel imports and improving national power grids.

A closeup image of the sun.

What is meant by green energy?

Green energy is similarly energy that is produced from naturally replenished resources. It's almost identical to renewable energy in that the act of turning these natural resources into energy is emissions-free. But the key difference is that green energy is created and obtained without causing harm to the environment—at any point during the process.

While green energy often comes from renewable sources, not all renewable sources can be considered green.

Why some renewable energy sources aren't technically “green”

There is some controversy around whether all forms of renewable energy are completely “green.” The overwhelming consensus, though, is that renewables are far more environmentally friendly than fossil fuels.

Biomass: Renewable, but not green

But, for example, biomass energy has enjoyed a reputation of being a clean, renewable energy source. It’s renewable, yes. But biomass is not a “green” energy source, and therefore isn’t so clean either. Biomass can refer to a broad-ranging, vague list of materials and substances, from organic waste of plants and animals to trees, crops, cotton, wool and even human sewage. Biomass energy is created by burning this material and turning it into a fuel source.

People that support biomass energy suggest that it’s more efficient to burn these materials for fuel than let them decay and potentially release carbon into the atmosphere.

Sounds good in theory, but biomass critics claim that it actually produces more greenhouse gas emissions—and they aren’t wrong. Studies from the Center for Biological Diversity have confirmed a myriad of negative environmental effects of burning biomass. Looking at California, for example, biomass power plants release more carbon pollution than coal for the same amount of electricity produced. Not to mention, cutting trees for biomass energy reduces the forest’s natural ability to sequester and store carbon.

So biomass—or more specifically the act of burning biomass for fuel—unfortunately cannot yet be considered a green energy source until solutions are developed to limit or offset its carbon pollution.

Solar, wind, hydro and other renewables: Mostly green, but require eco-friendly planning and development

Most other renewable energy sources can be green, and experts typically refer to them as such. It’s near impossible for anything to be 100% “green,” in that it causes zero emissions and no disruption to the environment or local animal habitats. Even riding your bicycle can cause microplastics from the tires to enter the environment.

But of course, the benefits of going green often far outweigh any minor negatives. And that’s the case for solar, wind, geothermal and hydro power.

Taking solar and wind for example. Once a solar farm or wind turbine is up and running, the act of producing energy from them is completely green. But the building of such systems can impact the environment, local habitats, crop development and other natural processes. So investors and developers must figure out “greener” ways to build and install the infrastructure.

Thankfully, many greener solutions are already happening, such as agrovoltaics or agrophotovoltaics, the act of building a solar farm on existing farmland. The farm's energy consumption is produced by clean solar power, limiting the farm’s greenhouse gas emissions compared to if they ran off fossil fuel energy. In addition, solar arrays are built in harmony with the land in a manner that maintains crop growth and doesn’t disrupt local habitats or limit the farmer’s operations. Ultimately, this is a much more efficient use of the land—and a greener way to install solar at scale.

An animated image of argovoltaics, when farmland is used for both crops and solar panels.

Renewable energy global consumption statistics

Despite green energy and renewable energy becoming more popular, fossil fuels still dominate the energy consumption for most countries across the world.

This is having a detrimental impact for us because 65% of global greenhouse gas emissions are the results of burning these fossil fuels for energy.

The shift towards renewable technologies could not happen sooner and we are progressing at an exceedingly fast rate into green energy adoption.

In 2019, 11% of the energy used by the entire planet was from a renewable source. Although this number continues to grow, we will experience setbacks in developing nations that haven't modernized enough to take full advantage of renewable energy. Despite 11% being used, almost 29% of global electricity generation was from a renewable source in 2020.

In the United States specifically, 20.6% of electricity generated in 2020 was from renewable sources. Some states and cities would experience days at a time where they were almost completely powered from a renewable energy source.

Renewable energy is also the fastest growing energy source in the United States, growing 42% from 2010 to 2020 and up 90% since 2000.

Hydropower and wind power have been the biggest sources of renewable electricity generation, with solar generation coming in third place (though solar likely wins the mainstream popularity contest). Solar is the fastest-growing renewable electricity source in the United States as residential adoption becomes more affordable and practical.

There's no arguing that there’s a clear trend towards renewable energy, especially in Western developed nations. While a completely renewable economy is extremely unlikely any time in the immediate future, it's easy to see a future where the majority of residential, commercial, and some manufacturing energy use is completely reliant on renewable energy sources.

As the costs continue to go down for green energy, the market will also react and encourage innovative businesses and entrepreneurs to focus more on technological solutions to the current problems we are facing—like with production, storage, and distribution of clean energy.

The economics behind clean, renewable energy

It's long been hoped that green or renewable energy would one day be the least expensive means of generating energy, paving the way for wide-scale adoption. And over the past several years, this has become a reality. The World Economic Forum announced that Renewables were the world's cheapest source of energy in 2020.

Aggressive government incentives and policies are making it cost-effective for corporations to embrace renewables. Funding is being poured into renewable technology research and innovation to make renewable sources easier to implement and deploy. Developers and investors are seeing the benefit of building renewable projects—so much so that it’s now actually cheaper to build and maintain a brand new solar or wind project, throughout its lifetime, than to simply maintain an already existing coal power plant.

This progress all helps renewable energy become more accessible and affordable to everyone, because cost-savings in the development and operational chain can lead to savings in the consumer’s wallet.

Economic potential of renewables

“Economic potential” is a metric used to determine the potential growth and profit that an entity (such as a country or corporation) could see from maximizing an untapped resource of which hasn’t been fully deployed. Essentially, is there potential to create a surplus of value—a profit—from this resource. In this case, the resources being clean, renewable energy.

As an increasingly affordable, cleaner alternative for power generation, renewable energy’s economic potential has risen significantly, according to the U.S. Department of Energy (DOE). It’s becoming clear that in the future, the cost required to generate renewable electricity may indeed be less than the revenue available to such an entity (i.e. it’s profitable to corporations, governments, investors). This bodes well for further investment and development towards renewables, which only increases their accessibility.

While economic potential is just one metric to look at, all signs point to renewable energy having major economic benefits in addition to its environmental and societal benefits.

Aerial view of St. Louis, Missouri.

Clean, renewable energy in cities

The capacity of renewable energy is expected to expand up to 50% by 2024. That 2019 report from the International Energy Agency found that not only is renewable energy capacity expanding, the number of solar, wind, and hydropower projects that are getting started are happening at their fastest rate in the last four years.

Although most predictions are erring on the side of caution, it's predicted that renewable energy sources will make up 30% of the world's electricity by 2024. This number will continue to grow as technology improves and renewable energy adoption increases.

When it comes to cities, renewable energy offers substantial benefits. Some of these benefits include a cleaner environment, more employment opportunities, and lower energy costs.

There are some great cities in the United States alone that are working hard towards becoming completely green and reliant on 100% clean energy. Examples include Santa Barbara, Denver, and both St. Louis and Minneapolis.

In 2017, Santa Barbara committed to 100% clean energy by 2045. By 2020 they reach their goal of using 50% renewable energy in all municipal buildings. In 2021 the city launched a utility arrangement program that should help to boost its renewable energy use for electricity supply from low 30% range up to 50%.

Denver is one of 10 different communities in Colorado that have planned to get rid of fossil fuels entirely. Their current goal is to be powered by 100% renewable energy by 2030 with an 80% reduction in carbon emissions by 2050.

In the Midwest, St. Louis and Minneapolis have both pledged to shift to 100% renewable energy. They plan to reach their goal by 2035 and 2030, respectively, a surprising trend from communities that have been so entrenched in coal and other fossil fuel production.

Ready for the renewable energy transition

There's no denying that renewable energy is here to stay. There is very obviously a trend towards clean energy and renewable sources across all levels of society and economics.

As costs continue to decrease and technology continues to improve, it's only a matter of time until the majority of cities in Western, developed nations adopt clean energy sources as their main source of electricity. Although it's impossible to predict specific timelines, it's likely that the current predictions for adoption will actually be accelerated as technology continues to see exponential growth with storage, production, and capacity.

This is one of the best things we can do for the future of our society and our planet. America leading by example will be the best way to encourage developed nations to jump on the renewable energy train, so everyone can begin to enjoy the benefits of a green energy future.

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