The Electric Reliability Council of Texas manages the state power grid, which contains all the electricity produced by all the state's utility companies. Spokesman Paul Wattles says the grid can handle high demand in July and August, but not in April, because that's when utilities typically take plants and equipment off-line for maintenance. This week's surprise heat wave and sudden high demand forced ERCOT to instruct utilities to make emergency reductions to keep the whole grid from collapsing.
"We issue instructions to the transmission providers in the region, and we ask them for a certain amount, a certain number, literally, of megawatts of load that they need to shed, and they implement the rolling blackouts."
Wattles says as long as the weather stays hot, more rolling blackouts are possible, so they're asking the state's eight million residential customers to help out by cutting their power use.
"One way to think about those residential customers is each one of those eight million is its own little power plant. If it can be turned down just a little bit it all adds up to some pretty serious generation and that's what we're lookin' for".
Wattles says the Monday situation was unusual, because in addition to the power plants down for maintenance, four more power plants tripped off at the height of the peak demand period, which meant that 20 percent of the state's generating capacity was out of service. He says that won't happen in the hot summer. Jim Bell, Houston Public Radio News.