By William Opalka

NYISO gave NRG Energy a green light to shut down two coal plants in western New York, saying reliability will be maintained through transmission. NYISO and National Grid were asked in the summer to perform a reliability study after NRG said it intended to close the 380-MW Huntley Generating Station and the 435-MW Dunkirk Station. (See NRG Plant Closures Could Impact Reliability in NY.)

“Based upon the expectation of the timely completion of the National Grid upgrades and that no other changes occur to the current and planned status of the New York electric system, reliability will be maintained through at least the year 2020 if Dunkirk is mothballed Jan. 1, 2016, and Huntley is retired March 1, 2016,” NYISO wrote in an Oct. 30 letter to the New York Public Service Commission (15-E-0505).

NRG said the plants were unable to compete with lower-priced natural gas generators. A legal challenge to a state subsidy negotiated for Dunkirk in its proposed repowering to natural gas created enough uncertainty to put that project on hold, NRG added.

NYISO said National Grid updated its local transmission plan to install capacitor banks at the Huntley 230-kV station by June 1, 2016. National Grid’s plan also includes possible system configuration changes and relay adjustments.

In its own letter to the PSC, National Grid said that it will complete in December three transmission system upgrades it proposed last year in the event that the Dunkirk repowering was delayed. “These projects contribute to the overall plan to operate the system reliably in the short and long term,” it wrote.