Rules designed to give the Electric Reliability Council of Texas greater flexibility in how it handles congestion over power lines went into effect on June 9. But during an emergency meeting of the Public Utility Commission, officials described other causes of the spikes, including shortcomings in the way software systems used by ERCOT calculate market prices.
Those issues helped push the so-called balancing market C"b," where ERCOT buys and sells power on 15-minute intervals to keep the system in balance C"b," over what was supposed to have been a cap of $2,250 per megawatt-hour.
Typically prices in the balancing market are around the $100 range, but in May it briefly spiked several times, hitting $4,000 on one day, and on June 1 it hit $3,536. The system allowed such spikes because the cost of relieving congestion on certain power lines were added on, creating what is known as the "shadow price."
The price spikes aren't signs of actual scarcity of power in the markets, observers say, but rather represent flaws in the rules used to run the markets.
"The last several weeks have been challenging," said PUC Chairman Barry Smitherman, referring to the role the spikes played in driving the four retailers C"b," E-tricity, National Power, PreBuy Electric and Riverway Power C"b," out of business.
While there are indications those smaller electric retailers had problems, they were worsened when they had to buy power from the balancing market during those spikes.
Thousands scramble Some 42,000 customers of those companies have had to find other providers in a hurry, with many moved to high-priced plans set by the same wholesale market that helped fuel the company failures.
Dan Jones, the independent market monitor for ERCOT, suggested during the meeting a number of fixes to the software used to calculate the prices, as well as reducing the maximum amount the shadow price can hit.
Speedy changes urged Shmuel Oren, a special adviser to the PUC, suggested other changes that precluded the need for software changes. Smitherman said he didn't care which method was used to make the changes, but rather that a fix that limits wholesale prices is put in place quickly.