Pablo Vegas, the CEO of Texas grid operator ERCOT, said supply will be lowest compared to demand around 8 a.m. Thursday. However, about 10,000 megawatts of operating reserves will help keep the lights and heat on, even as demand spikes, according to the ERCOT grid and market conditions .

An arctic blast has enveloped Texas, plunging temperatures well below freezing in many regions of the state. Despite the extreme cold, the state’s electrical grid operator says it has met the higher demand for electricity.

The Texas power grid served record-breaking wintertime demand for a second-straight day Thursday. Demand on the grid operated by the Electric Reliability Council of Texas topped 80.5 gigawatts amid sub-freezing temperatures early Thursday.