ERCOT staff told members of the Supply Analysis Working Group (SAWG) on Friday that the Texas grid’s summer peak demand is expected to reach 85 GW by 2027, a 22.36% increase over this summer’s peak.

But ERCOT is in good shape to meet the coming demand. The ISO’s November Generator Interconnection Status Report shows 20.6 GW worth of projects with interconnection agreements through 2020. Another 47.32 GW of capacity is being studied.

And despite the pending loss of more than 4 GW of coal-fired generation, ERCOT said it has more than 80 GW of available capacity to meet load this winter and spring. (See ERCOT: Sufficient Capacity for Winter, Spring.)

Staff’s 2018 long-range load forecast sees stronger growth along the coast and in Far West and South Texas, compared to the 2017 forecast, but weaker growth in North Central and South Central Texas. Based on Austin Energy forecasts and the utility’s focus on energy efficiency, staff project a 0.5% annual growth rate for the Austin area.

ERCOT’s most recent Capacity, Demand and Reserves report indicated the ISO will have an 18.9% reserve margin for next summer, with margins remaining above 18% the following three years. A revised CDR report incorporating the latest retirements will be released Dec. 18.

Texas is the fastest growing state in the country, having registered the nation’s largest annual population growth between 2010 and 2016, according to the U.S. Census Bureau. The state has been adding more than 200,000 people a year and will soon top 28 million.

NRG to Retire 806 MW of Mothballed Resources

NRG Texas Power notified ERCOT last week it plans to retire Greens Bayou Unit 5 and three other previously mothballed gas-fired units with a total capacity of 806 MW.

Greens Bayou Unit 5 dates back to the early 1970s and had a reliability-must-run agreement with ERCOT — the ISO’s first since 2011 — that was terminated in May. The unit was mothballed in 2010 and 2011. (See ERCOT Ending Greens Bayou RMR May 29.)

NRG also said it would retire three gas units at its Houston-area S.R. Bertron plant. The company shut down two 230-MW units and a 13-MW quick-start unit in 2011 for economic reasons. All three units were more than 50 years old.

The retirements will be effective Dec. 31, NRG said in its Dec. 5 filing.

— Tom Kleckner