ERCOT last week approved the shutdown of two plants, including Luminant’s coal-fired Monticello facility in East Texas, that will take nearly 2 GW of antiquated generation out of service.

Staff approved Monticello’s retirement, effective Jan. 4, saying the plant is not necessary for reliability operations. The plants’ three units, dating back to the 1970s, have a combined capacity of 1,880 MW but found themselves frequently out of the market. Luminant announced the units’ proposed retirement Oct. 6. (See First Shoe to Drop? Vistra to Retire 3 Texas Coal Units.)

The ISO also approved the indefinite mothballing of two gas units at the city of Garland’s Spencer plant, totaling 118 MW of capacity. The city filed notice with ERCOT on Oct. 4. The units began service in 1966 and 1973.

TAC Approves LDF Library Changes in Email Vote

ERCOT’s Technical Advisory Committee last week unanimously approved staff revisions to the ISO’s load distribution factor (LDF) library. The measure gathered 23 out of a possible 30 votes by email.

The vote was conducted after an Oct. 23 web informational session, which became necessary following revisions to account for a nodal protocol revision request (NPRR831).

Staff made changes related to private-use networks (PUNs), which are connected to the ERCOT grid and contain load that is typically netted with internal generation and not directly metered by the ISO. The change updates market systems to calculate a net load value for each PUN that will be included in the load zone price for all markets, when the load is a net consumer from the grid.

LDFs are used in congestion revenue rights and day-ahead market clearing activities, and developed using historical state estimator or supervisory control and data acquisition (SCADA). ERCOT staff added language to generate LDFs for PUN loads, which behave differently from non-PUN loads.

TAC’s October meeting, scheduled last Thursday, was canceled because of a lack of voting items.

— Tom Kleckner