AEP to buy up to 1.6 GW of Mainspring units and plans $4B Wyoming fuel cell project

American Electric Power has agreed to buy up to 1.6 GW of Mainspring Energy linear generators over the next eight years, with an initial 190-MW delivery set for next year, Mainspring said. Utility Dive reported the agreement could be worth up to $4 billion, with AEP able to buy about 200 MW a year and the generating units expected online within 12 months.

Mainspring Chairman and CEO Tom Linebarger said in an interview with Bloomberg Tech that the dispatchable units can run on natural gas, biogas or hydrogen and give AEP flexibility, including potentially firming renewable energy. "Of course, the speed to power means [AEP] can deploy them quickly where they need them to serve customers better," Linebarger said.

The units come in standard 2.5-MW configurations and convert fuel into electricity through a low-temperature, flameless reaction that produces close to zero nitrogen oxide emissions, according to Mainspring. The company said the AEP order is its largest purchase order to date and marks a shift into the investor-owned utility market.

AEP also said it plans to spend about $4 billion building a 702-MW fuel cell generation project near Cheyenne, Wyoming, under a 20-year power purchase agreement with Google, using Bloom Energy fuel cells. Construction is expected to start this year and the project is slated to come online in 2028. AEP said Bloom's fuel cells produce electricity without burning natural gas, and the project includes plans for carbon capture technology for near-zero-emissions power.

Google will buy power from Cheyenne Fuel Cell under the PPA, and that company is about 92% owned by AEP. AEP said the project follows agreements reached between Google and Black Hills Corp., which owns a utility serving the Cheyenne area, effective Sept. 30.

At the stated figures, the two projects carry different per-kilowatt costs: about $4 billion for 702 MW is roughly $5,700 per kilowatt, while $4 billion across 1.6 GW is about $2,500 per kilowatt. Both are ceilings or estimates rather than booked amounts; the Wyoming project also carries planned carbon capture.