It’s hard to talk about energy. Just ask any science teacher who has tried to define energy in a classroom. People stare blankly when you say, “It’s the ability to do work.” They furrow their brow when you tell them it’s not the same thing as “power.” You lose them completely if you bring up the laws of thermodynamics.
And yet, this thing that defies simple definition is critical to everything we do. Energy is fundamental to all facets of life on Earth. So it’s no surprise that folks who spend their days talking about energy have had to develop a special vocabulary, in order to have concrete discussions about an enigmatic concept.
In particular, if you want to talk about the effect that energy sources have on the environment, there is a large variety of phrases to choose from. Let’s look at a few of them, based on a literal interpretation of the words.
Concerned about pollution? Try clean energy. Afraid of running out of fossil fuels? You probably want renewable energy, or perhaps sustainable energy (more on these later). Is climate change your biggest worry? You may want to promote low-carbon energy. There is also alternative energy, which is attractive to people who know that they don’t like fossil fuels, but don’t want to specify exactly why. Even more vague is green energy, which refers to nothing specific at all and simply labels the person who says it as pro-environment.
Words come and go over time
With this long menu of phrases available, you might wonder which ones are used most often. Google Ngram Viewer lets you graph how often a word or phrase has appeared in books written in recent history. Plotting the five phrases below, we see that “renewable energy” has been the forerunner since the late 80’s.