The manager of the Texas electric grid said Wednesday that it should not be forced to fix a data error that increased electricity costs by millions of dollars and reprice a block of wholesale power sales because generators submit erroneous data so frequently it would have to adjust prices as often as once a day.
The Electric Reliability Council of Texas made its comments in response to a complaint filed with the Public Utility Commission by the electricity trader Aspire Commodities in Houston. Aspire asked regulators to require generators to repay a windfall of an estimated $18 million, the result of inaccurate production data sent to ERCOT by the Houston merchant power company Calpine. On May 30, electricity prices soared from $41 per megawatt hour to $9,000 after Calpine mistakenly signaled to ERCOT that it had taken some 4,000 megawatts of generating capacity — enough to power 800,000 Texas homes — offline.
Aspire, lost an undisclosed amount of money on electricity trading as a result of the spike. Aspire estimated that the price spike increased the costs of summer futures contracts by $245 million. Wholesale power prices and the cost of futures contracts are built into retail electric rates.