A Free-Market Energy Blog

“Renewable” Energy: In Search of Definition

By -- March 28, 2009

As a physicist with energy expertise and a long time environmental activist, I have grown increasingly concerned about a lack of common sense in the country’s energy debates. Even simple terms underlying our leading debates sometimes are poorly considered.

Consider the indiscriminate use of the term “renewable” energy. This is no academic annoyance, for right now the U.S. Senate is drafting a national Renewable Portfolio Standard (RPS). The first version is not a good start on President Obama’s new science directive.

Some problematic issues with RPS (federal and state) are:

1 – All renewables are treated alike (i.e., wind power = solar = geothermal, etc.);

2 – Any renewable is assumed to be better than most any conventional source (i.e. wind power is better than nuclear power);

3 – Renewables are given credit for making significant environmental changes (i.e., wind power is promoted as a major contributor to a carbon-free future);

4 – The huge cost to taxpayers and ratepayers for renewable implementation is written off as the price of “progress” or some other such platitude;

5 – The considerations of such stalwarts as grid reliability and dispatchability are now foreign concepts.

These problems mean that lawmakers are pounding this renewable square peg into the round electrical energy hole.

To my knowledge, there is no legal definition as to what renewable means — and the meanings proffered vary quite a bit. Technically, all sources of power are renewable, just at different rates — so the primary difference between a renewable and non-renewable is the rate of replenishment. That, in itself, should be a flag that this (in science terms) is a rather arbitrary and subjective definition. Who is to say what replenishment rate is good or bad, and on what basis?

Consider this definition:

Renewable is an energy resource that is replaced rapidly by natural processes… Non-renewable is any resource that is not replaced in a reasonable amount of time (our lifetime, our children’s lifetime, …) and is thus considered ‘used up’ and not available to us again.

Such words as “rapidly” and “reasonable” are subjective, relative terms—not scientific. Another pivotal aspect ignored in these definitions is the fact that although a source (e.g., wind) may be quickly replenishable, it uses up other resources (e.g., land) that are non-replenishable. We will run out of suitable land for wind power sooner than we will run out of fossil fuels. Shouldn’t the entire package be assessed as a whole?

Considering the variability, inadequacy, and political nature of its current iteration, there is some merit to just exterminate “renewable” from our vocabulary. But nature abhors a vacuum, so for sound bite reasons, if we refuse to use renewable, then we’d be well-advised to come up with a good replacement.

To me, then, our choices are to redefine “renewable” so that it makes more scientific sense, or to come up with a substitute.

I shared my conundrum with a group of energy experts. Interestingly, they were unanimous in their consensus that there was no hope of salvaging “renewable.”

One environmentalist said:

Several years ago, I came to the conclusion that the word renewable, applied as a source of energy, was a pejorative — and I treat it as such today (much as I do terms like windmills and windfarms). These are all words bowdlerized of any positive meaning, designed by the craven to casually separate people from the contents of their wallets. And so, in my public comments, I always connect renewables with fraud. Rather than refine the definition, I move that we ridicule the very concept. Instead I recommend promoting the principle of our making decisions based on energy density, or something in that vein.

A Ph.D. energy expert said:

When questioned on “renewable,” it is relatively simple to explain the First Law of Thermodynamics concerning conservation. Energy cannot be “new,” thus cannot be “renewed.” All we are doing is transforming one manifestation of energy into another — and we should be doing it in a “clean, non-polluting, preferably non-carbon-based” manner. This avoids (most times) the controversial subject of potential, unquantified global warming versus thermal equilibrium—which is too long and too complex for most listeners.

I normally use the phrases “clean energy,” “clean sources,” etc., but throw in the occasional “non-polluting” and “non-carbon-based.” This rather meets my concerns as a scientist and as a “green person.” Simplistic? Maybe. But a lot more accurate than “renewable.”

Anyway, the current leader of my unscientific poll is the term “clean.” (The runner-up is “sustainable.”)

What constitutes clean? My recommendation is that it should include any power source that does not produce more than 10 gCeq/kWh in production of electricity.

Now don’t get me wrong. This word change doesn’t nearly fix the situation—it is just one small step back towards a scientific footing. Clean (or sustainable) doesn’t necessarily mean reliable, or dispatchable, or any of the seven important criteria spelled out in my energy presentation.

The bottom line is that in this highly complex electrical energy area, we need to make decisions based on what is technically, economically, and environmentally sound. “Renewable” doesn’t adequately address any of these. If you have a term that is more comprehensive in its description as to what electrical power sources should be, please volunteer it!

Mr. Droz (degrees in physics and mathematics from Boston College; graduate degree in physics from Syracuse University) has worked for GE/AESD (Utica, NY), Mohawk Data Sciences (Herkimer, NY), and Monolithic Memories (Cupertino, CA).

A community and environmental activist in New York, Droz participates in solutions for electrical energy, water extraction, water quality, and property taxes. He lives on a lake in the Adirondacks and is an active member in such organizations as the Adirondack Council, Association for Protection of the Adirondacks, Residents’ Committee to Protect the Adirondacks, Sierra Club, and NYS Federation of Lakes. For more information, visit his website.


  1. rbradley  

    I believe that a nonrenewable (mineral) can be defined as physical science terms as nonreproducible in human time frames. But in economics or business terms, the fixity/depletion view becomes problematic and misleading.

    I discuss this in my paper, “Resourceship: An Austrian Theory of Mineral Resources,” at http://www.politicalcapitalism.org/aboutrb/Resourceship.pdf


  2. John Droz  

    A recent article by well known environmental advocate, James Lovelock, where he said (among several other things):
    “There is no such thing as renewable energy; it belongs as an idea with perpetual motion and other delusions but politicians and ideologues have become skilled at using enticing words to cover essentially rotten ideas.” (<>)


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