America’s Fuel Mix is Changing


Solar and wind energy call for new ways to manage the flow of electricity.

Renewable energy is big news. A road trip through the Midwest will likely take you through acres and acres of wind turbines and solar panels.

In 2021, a record amount of utility-scale solar was installed in the United States. The Bureau of Labor Statistics reports that wind turbine service technician will be the second-fastest growing job for the rest of this decade. The proportion of solar and wind that fuels your electricity quadrupled in the past 10 years.

So, why is less than 10% of electricity generated from wind? And less than 3% from solar power? The answer will teach you a little something about math—and a lot about how you get your electricity.

Electricity is generated by a variety of fuel sources—natural gas, coal, nuclear, hydroelectricity, wind, and solar. And this diverse mix of fuels is going through a major change.

What it teaches you about math is that a large increase in a small number still leaves you with a small number. If you’ve got a dollar and it triples, you are left with just $3. In the same way, wind and solar energy have grown from nearly nothing about 10 years ago.

It’s certainly big news that in the last decade wind power has more than tripled, from generating about 100 billion kilowatt-hours of our electricity to 378 billion kwh. And that solar energy has climbed from nearly zero, to 115 billion kwh.

But those impressive increases still leave renewable energy’s share of electricity generation far behind natural gas, at 1,579 billion kwh. Or coal, at nearly 900 billion kwh. Or nuclear, at nearly 800 billion kwh.

The story those numbers tell is that fossil fuels like coal and natural gas still generate most of our electricity—61%. But another part of that story is that our electricity fuel mix is being reshaped in two profound ways.

Coal is no longer king.

In the 1990s, coal generated more than half the electricity in the United States. Then a new natural gas drilling technique called “fracking” was so successful that by 2012, natural gas supplies soared to all-time highs, driving prices to 10-year lows. In addition to that cost competition from natural gas, environmental concerns put even more pressure on coal. While both coal and natural gas generation produces greenhouse gases, natural gas produces less. Utilities began running their efficient combined-cycle natural gas plants more and building new ones, even as many coal plants were run less or retired completely. Today, natural gas produces 38% of our electricity compared with coal’s 22%—less than half of what it was 30 years ago.

Renewables are not just new, they’re different.

The rise of solar and wind power means more than just two more significant sources in the electricity fuel mix. Today, 80% of our electricity is generated by heating water that turns a turbine. Coal and natural gas are burned, and even nuclear power, which provides 19% of our electricity, works by heating water. Those heat-based sources are dispatchable, meaning they can run 24/7 and adjust their output as electricity demand fluctuates. Solar and wind, on the other hand, work only when the sun is shining and the wind is blowing. As those intermittent sources become a bigger share of how we get our electricity, electric utilities are developing new ways to coordinate the flow of energy sources that have different characteristics.

A more diverse fuel mix calls for new approaches to the most basic function of electric utilities, which is keeping the lights on. One way utilities are managing these new power sources is through high-tech information analysis—utilities are increasingly hiring for a new job title, data scientist, a job the Bureau of Labor Statistics says will grow much faster than the average job for the rest of this decade.

There are likely to be more such changes as renewable energy is predicted to be the fastest-growing electricity fuel for the next 25 years.

Paul Wesslund writes on consumer and cooperative affairs for the National Rural Electric Cooperative Association, the national trade association representing more than 900 local electric cooperatives.