Texas should be ready for peak summer power demand *update*

Texas should have more than enough power generation capacity to meet peak demand this summer — which is expected to be lower than last year’s peak — the state’s main power grid operator said in its annual summer assesment.

The Electric Reliability Council of Texas says the grid’s power output should be able to exceed peak demand by 18.4 17.5 percent this summer – almost five four percentage points higher than the 13.75 percent threshold ERCOT sets for reliability standards.

**** Update

On June 2 ERCOT put out a correction saying the real reserve margin is 17.5 percent. ERCOT said three new gas-fired power plants totaling 565 megawatts were inadvertently counted twice because the date in which they were put into operation had been changed.


The peak demand forecast for this summer is 63,898 megawatts, nearly 2,000 MW less than last summer’s record-breaking peak of 65,776 MW set on Aug. 23.  

The demand forecast is based on long term historical average temperatures and economic conditions as measured by employment. 

Reserve margins are forecast to remain above the minimum target through 2013, an increase of more than 2 percentage points since the last assessment, which showed the reserve margin dropping below the minimum beginning in 2013.

“Our reserve margins for the next several years have improved due to the addition of more than 1,000 MW of additional generation,” said Kent Saathoff, vice president of grid operations and system planning.

The 2011 forecast includes 1,484 MW of capacity or “emergency interruptible loads” that are contractually obligated to be available to help with power emergencies.

Another 128 MW in demand reduction is expected this summer due to energy efficiency programs. 

The margin doesn’t include another 2,300 MW of generation capacity that is mothballed but could be brought back into service. 

Summer generation by fuel type is 64.4 64.2 percent natural gas, 25.8 26 percent coal, 7 percent nuclear, 1.1 percent wind, and 0.7 percent hydro, 0.1 percent biomass and 0.8 percent other.

In February the state experienced rolling blackouts when several days of cold weather led to the failure of dozens of power generation units throughout the state.

An investigation by the state’s independent market monitor concluded that the problem was not due to attempts at market manipulation, but a report by federal reliability officials concluded power plant operators could have done more to prepare for the cold.