09:49 AM EST, 11/05/2024 (MT Newswires) -- (Updates with PJM's statement in the sixth paragraph and recent stock movement in the first paragraph.)

Talen Energy ( TLN ) shares were up over 6% in recent Tuesday trading, a day after the US Federal Energy Regulatory Commission decided to reject an amended interconnection agreement to increase the capacity of an Amazon ( AMZN ) data center connected to Talen's Susquehanna nuclear plant in Pennsylvania, citing concerns over grid reliability and consumer costs.

"Co-location arrangements of the type presented here present an array of complicated, nuanced and multifaceted issues, which collectively could have huge ramifications for both grid reliability and consumer costs," FERC Commissioner Mark Christie said in a Friday filing.

PJM Interconnection, a regional transmission organization, submitted an amended interconnection service agreement between PJM, Talen's Susquehanna Nuclear and PPL Electric Utilities seeking to increase the data center's power capacity from 300 megawatts to 480 MW, according to the filing.

"Talen believes FERC erred and we are evaluating our options, with a focus on commercial solutions," Talen Energy ( TLN ) said in a statement on Sunday.

The company said it can continue to develop the first phases of the Amazon Web Services data center with the previously approved 300 megawatts.

"PJM is reviewing the Commission's order and assessing its implications," PJM said in response to MT Newswires' request for comment. "PJM will continue to work with the Commission, parties to agreements, stakeholders, and the states on issues relating to the co-location of large loads."

Amazon ( AMZN ) and PPL Electric Utilities did not immediately respond to requests for comment from MT Newswires.

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