Home Energy Devices Hold Untapped Potential for Strained Grids

This summer, as a historic heat wave strained Texas’ electrical grid and hiked power prices, Scott Stambush’s electricity bill went negative.

His four Tesla PowerWall battery chargers and 48 rooftop solar panels supplied the grid during times of peak demand, earning him revenue that amounted to a $649.71 credit on his monthly bill ending Sept. 12. The Sugar Land, Texas, resident said he wasn’t motivated by environmental causes. He just wanted to keep his lights on, and saving money was an added perk.

“I don’t think much about climate change and all that,” Stambush said. “I’m big on defending my ...