It’s easy enough to find information about energy—sometimes too much information to get a handle on. So, when thinking about energy in the United States, it’s not a bad idea to simplify things; there’ll be time for details later. For electricity, think of The Big Five. The five biggest power sources provided 95.5% of all the electricity generated in the United States in 2019. They were, from biggest to smallest: Natural Gas (38.4%), Coal (23.5%), Nuclear (19.7%), Wind (7.3%) and Hydropower (6.6%). Last year, the Big Five generated nearly all of total US output of 4.12 million Gigawatt hours of power.But just as energy is always moving, our sources of energy are a moving target as well. Go back 30 years, and you’ll see a very different picture. Since 1989, coal’s share of the electricity market has collapsed to less than half of what it was, while natural gas has more than tripled. Nuclear power and hydroelectricity have declined slightly. Oil-fired power plants have largely disappeared. Meanwhile, wind generation, which essentially didn’t exist in 1989, has more than made up for the end of the oil-burners. And most of these changes took place within the last decade, not gradually. If you get only one essential takeaway from this very brief overview, it should be this: America’s electrical grid is undergoing huge changes, along with the energy sources that power it, and the pace of those changes is accelerating.
As this series of articles continues, we’ll fly lower across this landscape to pick out more details, and to ask more questions. As coal declines, what choices will states like West Virginia and Montana confront? What new technologies are in the pipeline, and which old technologies can be reworked? Can we maintain our energy-rich lives in a climate that’s increasingly unpredictable? To what degree can we electrify transportation or buildings? And should we? The choices we make, and those that are made for us, will define our world for decades to come.