ERCOT Response to U.S. Rep. Joe Barton
U.S. Rep. Joe Barton, R-Texas, chairman of the House Energy and Commerce Committee
ERCOT study: 6,300 MW of wind had same load carrying capacity as 550 MW of thermal generation (i.e. 8.7%, due to unreliability of wind generation when power demand is highest)
"...wind does not blow at a constant level, and in Texas is often at a low level at the time of the peak electrical demand during summer afternoons. ERCOT studies the availability of wind generation using its historical wind generation data. Using 2006 data, ERCOT has determined that 8.7% of the installed wind capability can be counted as dependable capacity during the peak demand period for the next year. Conventional generation must be available to provide the remaining capacity needed to meet forecast load and reserve requirements. "
Source: ERCOTNote: Texas wind capacity is 20x Pennsylvania, so how little is the useful electricity from PA turbines?