Texas grid operators braced for near-record electricity demand Friday as triple-digit heat blanketed most of the state, sending power prices soaring. Demand on the power grid was expected to peak at 78.6 gigawatts, according to he Electric Reliability Council of Texas , the state’s main grid operator. The state has repeatedly set power demand records this year as a growing population and economy deal with the onset of summer weather. The National Weather Service issued an excessive heat warning Friday for most of central Texas, with temperatures expected to top 100 degree Fahrenheit (38 degrees Celsius) across the region. Power prices spiked in response, at times surging past $900 per megawatt-hour. However, ERCOT’s website forecast that power supplies should be able to cover demand for the day.