ERCOT today released its final summer Seasonal Assessment of Resource Adequacy (SARA), which anticipates tight conditions this summer, along with the semiannual update to its long-term Capacity, Demand and Reserves (CDR) report, which shows some improvement since the previous report was issued in December 2012.
Tight summer ahead, conservation calls likely
With tight operating reserves expected this summer, especially during the late afternoon hours on the hottest days, it is likely that ERCOT will initiate conservation alerts or power watches on some days. These alerts ask the public to reduce electric use to help ERCOT maintain reliability of the grid.
“We are expecting above-normal temperatures throughout summer in most areas of the ERCOT region,” said Kent Saathoff, an ERCOT executive advisor who has overseen various aspects of grid operations and system planning for several decades. “To help ensure there is enough generation to serve consumer needs, we likely will ask people to conserve power during the hottest hours of the hottest days.”
High temperatures typically drive electric demand in the ERCOT region, especially among residential consumers, who use more than half the electricity being consumed during the peak hours of the hottest days when air conditioner use is at its maximum.
ERCOT expects power demands this summer to peak at 68,383 megawatts (MW), slightly above the 68,305 MW all-time record set Aug. 3, 2011. One MW is enough electricity to power about 200 homes in the ERCOT region when electric use is highest, typically between 3 and 7 p.m. during the hottest days of the year.
The amount of generation available to serve peak electric needs is forecast at 74,438 MW, including 925 MW of new coal-fired generation from the Sandy Creek Energy Station in McLennan County and about 700 MW of new wind power resources.
More extreme scenarios could result in more generation outages than the forecast includes or an increase in demand of as much as 2,529 MW, if weather patterns similar to summer 2011 return.
“If generation outages exceed expected conditions during peak demand periods, or if we see a return of record-breaking conditions like those in 2011, ERCOT also may need to implement Energy Emergency Alert actions, with the possibility of rotating outages if needed to protect the grid,” Saathoff added.
Drought conditions are not expected to create problems for power plant operations over the summer months. However, if dry conditions persist, some plants may experience operational challenges later in the year.
ERCOT also released a preliminary outlook for fall 2013, which anticipates sufficient resources to serve expected demand.
Long-term outlook shows some improvement, work still needed
“ERCOT currently expects the planning reserve margin for summer 2014 to be slightly above its current 13.75 percent target, an improvement since the last long-term outlook was released in December,” said ERCOT CEO Trip Doggett.
The new CDR shows a planning reserve margin of 13.8 percent for summer 2014, up from 10.9 percent when the last report was released in December. While the peak electric demand forecast for summer 2014 remains just under 67,600 MW, assuming historical average summer weather, the total amount of anticipated generation resources has increased to nearly 77,600 MW from slightly less than 75,000 MW in the previous report.
The new total includes 385 MW of gas-fired power and 40 MW of new storage capacity in Harris County, as well as 90 MW of gas-fired power in Fort Bend County, 50 MW of new solar power in Bexar County, and about 1,080 MW of new wind generation in various locations. Two projects currently under construction by Panda Power Funds also have adjusted target commercial operations dates to make more than 1,400 MW of new natural gas-fired generation available in time for 2014 summer needs.
The 10-year outlook, which is based on a “Low Economic Growth” forecast from Moody’s Analytics and 30-year average temperatures, shows peak demand increasing to nearly 69,700 MW in summer 2015, with growth continuing annually up to more than 76,000 MW in 2023.
Load growth forecasts become less certain in the longer term. Also, available generation capacity only includes resources that have interconnection agreements and any necessary air quality permits in place.
Although reserve margins after 2014 remain below the 13.75 percent target, the future outlook has improved continually since 2011. Additional resources are in various stages of review and may be added to future reports.
Consumers’ role in a reliable grid
“We will continue to ask consumers to use power wisely, especially during the summer peak demand hours of 3 to 7 p.m.,” said Doggett. “Voluntary conservation when it is needed most — along with ongoing efforts to expand other demand response options — can help us ensure there is enough power for everyone when generation resources are tight.”
To keep up with real-time grid conditions and know when conservation is most important, consumers can download the ERCOT Energy Saver app on Apple (available at the Apple store) and Android (available on Google Play) mobile devices, follow ERCOT on Twitter (@ERCOT_ISO) or Facebook (Electric Reliability Council of Texas), or subscribe to EmergencyAlerts emails on http://lists.ercot.com.