Mainspring Energy Inc. announced that it has secured $258 Million in a Series F financing round to expand the company's linear generator power business and operations as it grows in both manufacturing and customer sales.

The Series F round was led by General Catalyst, and the firm's senior advisor Tom Linebarger will join the Mainspring board, along with Bethany Mayer, former chief executive officer of public technology company Ixia. Other investors include Amazon.com Inc.'s Climate Pledge Fund and Temasek Holdings Pte. Mainspring last raised $290 million in a Series E round in 2022.