As of 14 Oct 2026, Mainspring Energy has raised $258M across 1 verified round on record; latest: $258 Million Series F led by General Catalyst, announced 14 Apr 2025.
Mainspring Energy sells linear generators for flexible, low-emissions power solutions to businesses across various industries.
2 sources
Lightrock, LGT Bank, Khosla Ventures, and Gates Frontier are identified only as Mainspring’s earlier investors, so they are excluded from this round’s investor list.
| Round | Amount | Announced | Lead | Buzz |
|---|---|---|---|---|
| Series F [ HISTORY ]: An earlier round, from the company's own announcement, found while researching the company. Checked like any round, but not new, so it stays out of the daily feed and alerts; a date range shows it. | $258M $800M to date | 2025-04-14 | General Catalyst | No recent discussion |
2 sources [ VERIFIED · CORRECTED ] read against 2 sources
Lightrock, LGT Bank, Khosla Ventures, and Gates Frontier are identified only as Mainspring’s earlier investors, so they are excluded from this round’s investor list. | ||||