ERCOT Braces for Tight Reserves and Possible Power Shortages This Summer

Texas will have 74 GW of generation resources available this summer, including nearly 2 GW of capacity that had been mothballed—but the Electric Reliability Council of Texas (ERCOT) still expects tight reserves and expects calls for conservation to deter rolling blackouts, the Texas grid operator said last week.

The entity’s recently released Seasonal Assessment of Resource Adequacy for the ERCOT Region for summer 2012 suggests that based on resource availability and demand levels (driven by anticipated above-normal temperatures), ERCOT will need to declare an Energy Emergency Alert (EEA) on multiple occasions this summer.

The declarations "are not likely to result in the need to institute rotating outages," but if a higher-than-normal number of forced generation outages occur during a period of high demand, or if record-breaking weather conditions such as had occurred last summer lead to even higher than expected peak demands, the ERCOT system will "likely have insufficient resources available."

The grid operator was forced to cut power to large industrial users last summer to avoid rolling blackouts as the state grappled with surging power demand during a long heat wave and a devastating drought. Power demand in ERCOT’s operational region—covering about 85% of Texas—hit three consecutive records in one week, reaching 68,294 MW on Aug. 3. ERCOT had come under regulatory scrutiny in February 2011 when an unusually bitter cold snap crippled several power plants and forced the grid operator to implement rolling blackouts.

Drought conditions in Texas improved during the winter and early spring in many river basins, but potential risks to generation capacity persist while the state remains under drought conditions, ERCOT said last week. This summer is expected to be warmer and drier than the 15-year historical average, but less extreme than last summer, the National Weather Service has said.

Nearly 74 GW of generation resources are available, including 1,984 MW of mothballed capacity. Generators of the shuttered plants had notified the grid operator that they planned to bring these plants back online to meet high summer demand.

One aspect that helped the situation was a federal court stay of the Environmental Protection Agency’s Cross-State Air Pollution Rule, which enabled some units to continue running this summer, ERCOT said.

Texas could also depend on more than 2,075 MW of wind power in the coastal region, "which tends to be available to the grid during the late afternoon when it is needed most in the summer," the operator said. "Wind power generation in the ERCOT region continues to set records, and instantaneous wind power served nearly a quarter of ERCOT load twice in April." Another 48 MW of commercial-scale solar power, including about 20 MW that went online this spring, has also been added in ERCOT since last summer.

Additionally, when demand is high and generation tight, some large power users have agreed to reduce their demand on the grid in return for compensation. Summer projections include about 1,500 MW of demand response resources, which include energy users that reduce or drop their energy use at ERCOT’s request if generation reserves drop below 1,750 MW.

“From my perspective, making it possible for more loads to respond to tight conditions is one of the most important things we can do in the short term,” ERCOT CEO Trip Doggett said last week.

According to new rules adopted by the Texas Public Utilities Commission and new ERCOT market protocols approved by the ERCOT board in April, ERCOT’s Emergency Interruptible Load Service (EILS) program will change on June 1 to Emergency Response Service (ERS) and will add distributed generation to the resources ERCOT could call upon to help stabilize the grid during emergencies. Through EILS, some users previously have provided about 400 MW of capacity during emergencies. Under the new ERS rules designed to increase the potential benefits of the program, smaller loads also will be able to respond to calls for additional capacity.

“We have taken an ‘all of the above’ approach to meeting Texans’ electricity needs this summer,” said Chairman Donna Nelson of the PUC. “I particularly appreciate efforts from generators to bring power plants back on-line to help keep our air conditioners running.”

Sources: POWERnews, ERCOT, PUC