Recently, Secretary of Energy Rick Perry told Fox News that President Trump supported “clean energy” and included natural gas exports and nuclear energy support as examples of the administration’s “clean energy” accomplishments. This wasn’t surprising, but I wondered if the viewers understood the nuances of the term “clean energy.”

Our “energy” words matter. They not only shape public opinion, but they also help consumers, businesses, and voters to choose the type of energy they want to use in their homes, businesses, and governments. While very different, “energy,” “renewable energy,” and “clean energy,” are often used interchangeably. They’re not the same, so we need to get on the same page.

With that in mind, I’d like to offer the following definitions and context for the three most common types of “energy” terms used in media, marketing, and politics. While my descriptions aren’t meant to be technical, I hope they’ll help people to understand what is meant when media, politicians, and marketers choose their energy words.

“Clean Energy”

“Clean Energy” (and “green energy”) can be purposely ambiguous and broad. When used, it can include any source of energy that emits less pollution and greenhouse gasses, such as all of the renewable energy sources, nuclear, carbon capture and storage (CCS), clean coal technology (CCT), hydrogen fuel cells, and combined heat and power (CHP), and natural gas.

“Clean energy” may sound clean, but that can be misleading. When politicians want to include nuclear power and natural gas with their clean energy goals, they’ll often label their plans as a “clean energy plan” or a “green energy plan.” If they meant a “100% renewable energy plan,” that would exclude nuclear and other low carbon energy sources.

As an example, the U.S. Department of Energy’s website’s “clean energy” page lists nuclear and hydrogen as clean energy sources. While hydrogen fuel cells don’t directly emit greenhouse gasses, they do use natural gas to convert hydrogen into electricity, making the “clean energy” term confusing. Solar energy may replace natural gas in the future, but not yet.

Similarly, nuclear energy emits zero carbon, but it’s very different from the renewable energy of solar, wind, and geothermal energies that are listed on the same page. Thus, readers need to understand that all “clean energy” does not have the same effects as “renewable energy.”

While not listed on the DOE website, Secretary Perry cited natural gas as “clean energy” in his Fox News interview. Once again, he was using the “clean” label to equate gas with renewable energy, which is misleading. While natural gas emits less C02 and pollution than coal power plants, it still emits CO2 into the atmosphere. In addition, natural gas extraction via fracking emits methane, a potent greenhouse gas.

CCS technology may also be described as “clean energy,” but keep in mind that it still emits greenhouse gasses when coal or gas is mined or fracked. Also, the technology has yet to work or made cost-effective.

“Renewable Energy”

“Renewable Energy” is much more precise than “energy.” In my definition, it includes any kind of electric or thermal power that is sourced from a natural, non-burning, and renewable fuel source. This includes solar, wind, geothermal, hydro, and wave power.

As defined, “renewable energy” is the least ambiguous of our cleantech energy terms. It’s easy to understand that solar, wind, geothermal, hydropower, and wave power are generated from an infinitely renewable natural fuel, such as the sun and wind. To me, these technologies are what people imagine when they hear “clean energy” and “green energy.”

Nevertheless, some nuclear companies and advocates may describe nuclear power as being a renewable type of energy because it doesn’t emit greenhouse gasses. However, uranium isn’t “renewable.” Nuclear plants continue to need uranium fuel, and their nuclear waste needs to be safely stored.

While I’d like to say that “green energy” has the same definition as renewable energy, it’s often used like “clean energy.” When hearing “green energy,” readers should understand that the term may indicate non-renewables.


“Energy” is the broadest of generic energy terms. It can intentionally refer to any source of power, including fossil fuels, renewable energy, nuclear, carbon captured energy, or any kind of power that heats, electrifies, or fuels transportation.

Reader beware when reading or hearing about “energy companies” without any modifiers. Oil, natural gas, and coal companies often call themselves “energy companies” to minimize their fossil fuel energy businesses. In truth, they are oil, gas, and coal companies, even when they’re minimally investing in renewables.

Similarly, nuclear energy companies will also call themselves “energy companies.” Like fossil fuel companies, nuclear companies are attempting to cloak their names from nuclear power’s history of accidents, cost overruns, and waste issues.

However, “energy” isn’t always used to hide negative context. Ironically, solar, wind, battery, and other cleantech companies will brand themselves with “NAME Energy” instead of “NAME Solar” to make themselves appear as large as fossil fuel companies. Also, renewable energy companies see “energy” as a simple term that reflects that they install or manufacture more than one type clean energy, such as a solar company that also installs wind or energy storage. Finally, the term helps promote renewable energy as a reliable, everyday mainstream energy that can compete with fossil fuels.

Given the positive attributes of solar, wind, hydro, etc., I’d recommend renewable companies maintaining the word “solar,” “wind,” etc. in their brand. They could also add “renewable” to “energy.” Those extra words extend the brand name, but they also contrast the company with generic fossil fuel “energy” companies.

All of these energy terms are widely used today and will continue to be used. My hope is that energy communicators will be more selective and specific when they use them and that readers will be more aware of their meanings when these terms appear in media, politics, and marketing.

Tor “Solar Fred” Valenza is a “renewable energy” marketing and communications consultant.