Texas power grid faces limited solar energy supply

The Texas power grid's operator has asked consumers to use less energy as clouds threaten access to essential solar power.

The Electricity Reliability Council of Texas asked residents and business to voluntarily conserve energy for the second time in three days amid a continuing heat wave.

Following Monday's conservation appeal, Wednesday’s notice similarly calls for conservation from 2 to 9 p.m., during which residents are encouraged to raise their thermostats to 78 degrees and postpone using major appliances such as dishwashers or dryers.

Unlike Monday’s appeal, ERCOT included forced thermal outages and solar as major factors in reducing grid supply on Wednesday.

According to a spokesperson for ERCOT, developing cloud cover in West Texas has reduced the amount of solar generation.

This particular factor is significant, as Texas often experiences heat and low wind -- which drive electric demand and decrease natural energy gained from wind --- but rarely loses access to its solar energy.

According to data from ERCOT, the percent of dispatchable energy installed on Wednesday’s tightest hour was at 84%, while that of solar power was at 68% percent.

Wind, usually a weak contributor in times of extreme heat, was measured at only 12% installed capacity at the day’s tightest hour.

Texas energy consultant Doug Lewin told Texas Monthly that the state’s power grid has twice the amount of solar power it had last summer, and three times what it had 18 months ago.

According to Lewin, Texas set a record for solar power on Monday. It is the renewable energy, such as solar power, that is allowing the grid to sustain power and avoid blackouts, Lewin said.

The demand, despite the conservation appeal, has soared amid extremely dry and hot temperatures across the state.

According to the National Weather Service, Austin was projected to have a heat index of 110 degrees on Wednesday, which has held its triple digit temperatures all week.

San Antonio is projected to stay above 100 degrees throughout of the rest of the week, with a high of 104 on Wednesday.

In northeast Texas, Dallas will also stay in the triple digits, with Wednesday’s heat index resting at 105 degrees.

Amid the persisting heat, power demand has broken two records already this week.

On Monday, demand set a record hitting 78,264 megawatts as ERCOT called for voluntary energy conservation.

On Tuesday, that record was broken again, peaking at 78,419 megawatts of demand.

Wednesday is projected to break that record once again, with ERCOT forecasting demand to be 78,451 megawatts.

According to a spokesperson from ERCOT, Texas only has 906 megawatts of energy available beyond the day’s forecasted demand.

That figure falls at less than half the threshold that requires the grid to start taking emergency measures, according to data from ERCOT.

According to the power grid, the conservation appeal on Monday led to consumers lowering energy use by 500 megawatts.