FirstEnergy Solutions Corp. (FES) notified PJM Interconnection, LLC (PJM), the regional transmission organization, of its plans to deactivate four fossil-fuel generating plants in 2021 and 2022. FES is closing the plants due to a market environment that fails to adequately compensate generators for the resiliency and fuel-security attributes that the plants provide. The plants, representing a total of 4,017 megawatts (MW) of generating capacity, are to be deactivated on the following schedule: Eastlake 6, Eastlake, Ohio (24 MW, coal), June 1, 2021, Bruce Mansfield Units 1-3, Shippingport, Penn. (2,490 MW, coal), June 1, 2021, W.H. Sammis Diesel, Stratton, Ohio (13 MW, diesel oil), June 1, 2021 and W.H. Sammis Units 5-7, Stratton, Ohio (1,490 MW, coal), June 1, 2022. In the interim, the plants will continue normal operations. Plant closures are subject to review by PJM. If PJM determines that one or more of these units may be needed for grid reliability purposes, FES will provide information and estimates of the costs and timing to keep some or all of the units open. The company filed requests for exemption from PJM's must-offer rules both for these fossil-fired plants and for FES's three nuclear generating plants, whose planned deactivations were announced March 28, 2018. Under the must-offer rules, generating companies in the PJM region are required to make their plants' capacity available to the grid in regular capacity auctions unless granted an exception. The annual auctions are held to secure capacity three years in advance. FES is seeking exemptions from auctions covering the 2022-23 delivery year and beyond. The FES nuclear plants and their deactivation dates are: Davis-Besse Nuclear Power Station, Oak Harbor, Ohio (908 MW), May 2020, Beaver Valley Power Station, Shippingport, Penn., Unit 1 (939 MW) May 2021 and Unit 2 (933 MW) October 2021 and Perry Nuclear Power Plant, Perry, Ohio (1,281 MW), May 2021.