The Electric Reliability Council of Texas just completed a study of energy sources like wind and solar power. 

Public Citizen spokesperson Kaiba White says solar's value has been upgraded.

“They made some changes at ERCOT based on studies that have been going on for a couple of years and solar is now going to be given a 100 percent capacity value,” she explains.

Start up cost is still a challenge, but government subsidies have contributed to the growth.

“That doesn't mean that it is producing all the time,” she says, “because obviously it is not.

“But it does mean that it is expected to be producing when we need it the most, at peak power demand.”