May 24 (Reuters) - U.S. power company Exelon Corp said Thursday that three of its nuclear plants did not clear in the annual capacity auction used by the PJM power grid operator to ensure enough energy resources are available to meet demand in its U.S. Mid Atlantic and Midwest region.
The companies with units that clear in the auction will be paid for being available in the 2021-2022 delivery year.
Exelon said its Three Mile Island, Dresden and all but a small portion of its Byron nuclear plant did not clear the auction. Three Mile Island is in Pennsylvania, and Dresden and Byron are in Illinois.
Exelon said the results "underscore the urgent need for policy reforms to resolve acknowledged flaws in market rules that fail to properly value the resilient, zero-emissions power provided by nuclear plants."
This marks the fourth consecutive year that Three Mile Island has failed to clear in the PJM auction. Exelon has said it plans to shut Three Mile Island in October 2019.
Across all of PJM, 10,643 megawatts of nuclear capacity did not clear in the auction, compared with 3,243 MW that failed to clear last year, Exelon said. One megawatt can power about 1,000 U.S. homes.
That is the largest volume of nuclear capacity ever not selected in the auction, Exelon said.
PJM, the biggest U.S. power grid, operates the system in all or parts of 13 states from New Jersey to Illinois.
Reporting by Scott DiSavino; Editing by Steve Orlofsky