The round was led by global growth equity investor Lightrock and joined by others including Khosla Ventures, Bill Gates, Fine Structure Ventures, the private equity firm affiliated with the parent company of Fidelity Investments, Princeville Capital, and Lineage Ventures. Mainspring will use the funds to develop new linear generator models and to accelerate the commercial, industrial, datacenter and utility adoption of Mainspring Linear Generators producing zero-carbon electricity.

Driven by its vision of the affordable, reliable, zero carbon grid of the future, Mainspring is delivering a breakthrough new category of power generation - the linear generator - to leading commercial, industrial, and utility customers. to increase their energy resilience, generate cost savings, and meet their sustainability and climate goals. Customers include Fortune 500 companies like Kroger and Lineage Logistics, as well as utilities like PG&E, Florida Power and Light, and others.