By Tom Kleckner
ERCOT enters 2019 with a major coal plant going into mothballs and two aging gas units set for decommissioning.
After burning the last load of coal at its J.T. Deely plant on New Year’s Eve, San Antonio utility CPS Energy is now in the process of mothballing the two units, which date back to 1977 and 1978.
The municipal utility in 2011 said it would retire Deely by the end of 2018, 15 years ahead of schedule, thus avoiding millions in environmental retrofit costs. It notified ERCOT of its plans to mothball the plant in 2013, but it must submit a notification of change of generation resource designation (NCGRD) before officially retiring and decommissioning the units.
CPS spokesperson Trace Levos said the utility plans to begin razing the plant in 2025, but utility officials are also pondering converting Deely into a gas-fired plant.
ERCOT spokesperson Leslie Sopko said the grid operator will not have to conduct another reliability-must-run study whenever CPS is ready to retire the units, as the ISO already considers the units to be unavailable.
Deely’s two coal units have a combined capacity of 871 MW. Along with Luminant’s shuttering of three coals plants in late 2017, ERCOT will have seen slightly more than 5 GW of coal-fired capacity shut down over a year. (See ERCOT OKs Luminant Coal Retirements.)
The Texas grid operator survived record-breaking demand last summer without resorting to emergency measures. It is expected to enter this summer with a historically low reserve margin of 8.1%, almost three points lower than last year. (See ERCOT Faces Tight Summer Margins, Market Changes.)
Meanwhile, NRG Texas on Dec. 28 submitted an NCGRD to ERCOT, saying it intends to decommission and permanently retire two previously mothballed gas units at its SR Bertron plant near Houston, effective Jan. 23.
The Eisenhower-era units each have a capacity of 230 MW. They were shut down for economic reasons in 2011.