A portion of the Oncor substation on Elms Road in Killeen is shown Friday. The state says it should be able to meet energy demands this summer, but extreme heat could put a strain on the system as it did during 2011.

By Sean Wardwell
Killeen Daily Herald

Last May, the Electric Reliability Council of Texas announced its expectation of having adequate power supplies for the coming summer.

Nearly one year and several power advisory warnings later, the council is changing the way it predicts power availability through peak times with quarterly forecasts.

“We developed a new concept this year that we call a seasonal assessment. It’s more of a deterministic forecast,” said Dottie Roark, ERCOT spokesperson.

Previously, ERCOT looked at a historical backcast of highs and lows when assessing power availability. However, that forecast model did not take into account extreme weather.

“If you have an extreme year, like we did in 2011, it doesn’t show up on that forecast,” said Roark.

ERCOT hopes that the change in peak forecasting methodology will help alleviate concerns over power expectations going into the summer. One of these assessments for the rest of the winter has already been completed, showing adequate power resources through the rest of the season.

That did not come without warning, though.

“If extreme weather results in a significantly higher than normal amount of forced generation outages and high electrical demand, the ERCOT system could have insufficient resources available to serve that demand,” states ERCOT’s most recent quarterly forecast. “This insufficiency would result in the need for rotating outages to maintain the integrity of the system as a whole.”

Roark said ERCOT is concerned over the state of power reserves, as well. Late last year, the council was informed that two power generation plants owned by Luminant Energy would be mothballed in 2012, due to pending federal regulations on cross-state air pollution.

However, a federal court blocked implementation of those rules, which were scheduled to take effect Jan. 1, allowing the plants to stay open.

While keeping the plants in service allows ERCOT to meets its target for power reserves, the council is still 1,500 megawatts short of its reserves compared to last year.

Karl Green, local area manager for Oncor, said his company has always been stable in terms of generation and capacity, but still stresses conservation.

“Our biggest concern is summer. That’s when you have the biggest use of electricity,” he said.

For now, ERCOT is keeping an eye on the sky, hoping to avoid a repeat of last year.

“We’re not out of the woods if we have summer temperatures like last year,” said Roark.