There's plenty of wind deep in the heart of Texas—not to mention a lot of other places in the Lone Star State. And while Texas may be oil country, those breezes are playing an ever-increasing role in keeping the lights on.

"If we look at wind as a percent of our total energy over the last 10 years it's grown from 5 percent up to it just exceeded 17 percent last year," said Beth Garza, director of the Electric Reliability Council of Texas (ERCOT) Independent Market Monitor. "It's been a steady growth through the years."

The nonprofit ERCOT operates wholesale markets that coordinate the scheduling of power on the Texas grid. Electric cooperatives are among ERCOT's members.

Garza told the recent 2018 EIA Energy Conference that in 2007, turbines were installed in about 14 of Texas' 254 counties. Today, that's up to around 55 counties.

"We built transmission to enable wind generation," said Garza, noting a $7 billion investment in recent years.

According to Energy Information Administration figures, in 2016, Texas saw 57.5 million megawatt-hours of wind generation in the electric power industry, tops in the nation. It was about 12 percent of the state's total electric power industry generation. It also accounted for a quarter of the nation's nearly 227 million MWh of wind generation in the electric power industry that year.

In fact, EIA figures show Texas was far ahead of its closest competitors, Iowa and Oklahoma, each of which had 20 million MWh of wind generation in the electric power industry in 2016.

"As we have opened up the Panhandle, if you will, through transmission expansion, we've accessed windier areas," said Garza.

And the newer sites produce more, thanks largely to technological improvements including better turbines and taller towers.

With that increase in wind generation has come a decline in the amount of curtailment—the reduction in electricity generation below what the turbines are capable of producing, for transmission reliability. Garza said that in 2008, with approximately 15 terawatt hours of wind, estimated curtailment was 8.4 percent. In 2017, with more than 60 TWh of wind, estimated curtailment was 2.5 percent.