Solar and wind power have now together produced more than 10 percent of the US’s electric needs for the month of March 2017. It’s the first time that the penetration of renewables has been so high in the US.  

That’s according to the US Energy Information Administration’s Electric Power Monthly most recent report. The mostly report reveals interesting facts about the US’s energy supply and its transition to more sustainable, renewable energy on a regular basis.

The report said that electricity generation from wind and solar power will probably exceed 10 percent of the US electric generation in April 2017, but fall to less than 10 percent through the hotter summer months. Last year, however, wind and solar made up 7 percent of the US’s electric generation sources in 2016, with more wind and solar coming online throughout 2017, that number could move up. 

Looking more broadly, EIA Principal Contributor Owen Comstock said that Texas was the biggest producer of renewable energy in the US. “Nearly all of this generation was from wind, as Texas generates more wind energy than any other state,” Comstock said. “As a share of the state’s total electricity generation, wind and solar output was highest in Iowa, where wind and solar made up 37% of electricity generation in 2016. In addition to Iowa, wind and solar provided at least 20% of 2016 electricity generation in six other states.”

Only two of the top 12 states for renewable energy had more solar than wind, California and Arizona. According to the report, Iowa, Kansas, and North Dakota had no utility-scale solar power and few small-scale solar systems like rooftop arrays. While the EIA formerly only counted only utility-scale power in the monthly report, it began tracking small-scale solar, like rooftop solar in 2014, helping to show a more complete picture of the US’s renewable energy makeup. 

The monthly report also noted that renewable electric generation at the state level is generally highest in the spring or fall. “These seasons are times of generally low electricity demand, combined wind and solar generation also reached its highest share of the U.S. total during these times of year,” Comstock said.

While the output of wind farms varies seasonally and geographically, solar produces the most electricity in the summer.