The amount of electricity generated by renewable resources hit a record 28% in April, a breakthrough number that shows how important renewable energy has become in U.S. energy markets.

“It’s a ‘Wow’ moment,” said Peter Kelly-Detwiler, an energy analyst and author of “The Energy Switch,” a recent book about the transition to a carbon-free energy economy.

The percentage of U.S. electricity produced by renewable energy from wind, solar and hydroelectric dams has been steadily rising, from 8.6% in April 2001 to this April’s 28%. Those numbers were released this week by the U.S. Energy Information Administration, which tracks energy data for the nation.

What explains the surge?

There are several reasons. At the top is that wind and solar installations dominated U.S. energy buildouts.

“Basically, the only things we’ve added to the grid in the past decade are wind, solar and natural gas,” said Harrison Fell, an economist and engineer at Columbia University, where he co-leads the Power Sector and Renewables Research Initiative.

That’s happening for two reasons. The first is cost. Renewables are simply the most economically competitive power currently available, Kelly-Detwiler said.

In 2021, the cost of producing a megawatt-hour of electricity from a new wind turbine was $26 to $50. The same amount of electricity from the cheapest type of natural gas plant ranged from $45 to $74, according to Lazard, a financial advisory firm that publishes annual estimates of the cost of producing electricity. 

Federal and state mandates and incentives to increase the amount of clean energy used also help, Fell said. 

“When you do the math on what’s the most profitable thing to add, it’s often going to be wind and solar at this stage,” he said.

Was weather a factor?

Yes. April tends to be a particularly windy month, and this spring was windier than most, Fell said.