FERC has denied another generator’s request for make-whole payments for natural gas it purchased that was never used during the event, citing rules against retroactive ratemaking.

FERC rejected requests by two PJM generators seeking the recovery of “stranded” natural gas costs incurred during the polar vortex last year.

This winter bumped aside last year’s peak load record, but PJM's system experienced a fraction of the stress brought on by the January 2014 polar vortex.

FERC approved PJM's Capacity Performance proposal, a dramatic restructuring of the RTO's capacity market.

FERC backtracked from its January order directing ISO-NE to develop a market-based approach for its winter reliability program later this year.

A repeat of last winter should not imperil the nation's power system, NERC said. Meanwhile, FERC ordered RTOs and ISOs to file reports on their efforts to ensure generators have adequate fuel.

PJM stakeholders deadlocked for the third time Thursday on changes to the $1,000/MWh energy offer cap, leaving it to the Board of Managers to decide whether to seek FERC approval of any changes.

FERC said PJM should not have included a 10% adder in its calculation of make-whole payments to generators whose costs exceeded the offer cap last winter.

ISO-NE "will be in a precarious operating position for the next several winters due to the natural gas pipeline constraints," spokeswoman Marcia Blomberg said.

PJM is hoping that testing of little-used generating units will ensure they are available if cold weather strains its reserve margin.