Mainspring (EtaGen)

Problem.

EtaGen, a mission-driven startup advancing global access to low-carbon and dispatchable energy, had developed a truly new category of power generation. The company needed a new name that would be globally accessible and carry the innovative story of their linear generator — delivering onsite, fuel-flexible power at lower cost and lower carbon than the electric grid.

Solution.

Mainspring, a real word, represents the principal driving force in motivating or maintaining a movement. Without being too literal, the name actively supports a company at the heart of the energy revolution. Furthermore, it links to the linear generator’s function and positively reflects the company’s pride in bringing to market a physical product with world-class engineering and craftsmanship.

In April 2025 Mainspring secured $258 Million in Series F financing to expand as the company’s linear generator power business and operations. Mainspring CEO and Founder Sharon Miller commented, “Mainspring is fortunate to have the support of many of the top energy investors in the world, with a strong international perspective, as we prepare for our next phase of growth.”