Generac Holdings Inc. is seeing rising demand for its backup power generators in Texas, where searing heat has been testing the reliability of the state’s main electric grid.

“We’ve seen a dramatic increase in the Texas region in sales leads for our generators and battery backup systems,” Chief Executive Officer Aaron Jagdfeld said in an interview Monday. “Texas has been a great market for a long time, so this will only add to that in the future.”

Generac, which says it’s the top maker of home backup generators, saw its shares hit a four-month high last week when the Texas grid operator urged residents to conserve electricity to prevent blackouts. The grid operator issued a weather advisory for this week as a punishing heat wave is forecast to linger and drive up electricity demand while residents crank up their air-conditioners.

Generac customers provided about 1 megawatt of backup power from their home generators to the Texas grid last week, Jagdfeld said. One megawatt is enough to power about 200 Texas homes. Customers who have installed the company’s smart thermostats and allow a local utility to adjust temperatures to reduce stress on the grid contributed about 34 megawatts of power savings last week as well, he said.