Funding round
Mainspring Energy Series E
Mainspring Energy, which works in linear generator manufacturing in Menlo Park, raised $150M in a Series E round announced on 24 May 2022, led by Lightrock. 6 firms took part, with 1 individual investor. It is Mainspring Energy's third venture round on record; the one before was a Series D in May 2021.
$150M
Amount raised
Not disclosed
Post-money valuation
6
Investors
1 lead
Valuation
What this round says about the price
Mainspring Energy did not disclose a valuation in this round; its last disclosed one was $440M at the Series D (May 2021). It came 12 months after Mainspring Energy's Series D. It is 26% of the $586M Mainspring Energy has raised in the venture rounds on record. Mainspring Energy raised again 35 months later: a Series F round of $258M in Apr 2025.
Mainspring Energy's funding rounds
Mainspring Energy has 4 venture rounds on record and 1 other deal. This one is highlighted.
Investors
Who put money in
Lightrock led the round with 5 other firms.
Lead investor
- Lightrock backs 62 venture-backed companies new investor
Also in the round
- Khosla Ventures backs 396 venture-backed companies new investor
- backs 20 venture-backed companies new investor
- Princeville Capital new investor
- Lineage Ventures new investor
- Breakthrough Energy backs 113 venture-backed companies
Individual investors: Bill Gates.
Use of proceeds
What the money is for
According to the announcement, the money goes to product development, geographic expansion, sales and marketing, scaling operations and working capital.
- Product development
- Geographic expansion
- Sales and marketing
- Scaling operations
- Working capital
Comparable rounds
How it compares
The closest in time: Series E rounds in any sector within 6 months:
| Company | Announced | Amount | Post-money | Led by |
|---|---|---|---|---|
| Tech Companies | 9 May 2022 | $120M | not disclosed | H.I.G. Growth Partners |
| Machinery parts manufacturer | 5 May 2022 | $100M | not disclosed | Activate Capital |
| Tech Companies | 4 May 2022 | $90M | $3.00B | BOND and Accel |
| Shield AI Aerospace and Defence | 31 May 2022 | $90M | $2.30B | Snowpoint Ventures |
| Martial Arts Gyms | 19 May 2022 | $30M | $500M | Waverley Capital |
| Tech Companies | 21 Apr 2022 | $260M | $3.80B | Baillie Gifford |
| Aledade Health Care Services | 6 Jun 2022 | $123M | $3.10B | OMERS Private Equity |
| Insurance - Agents, Carriers & Brokers | 29 Apr 2022 | $120M | $900M | Amansa Capital and Jungle Ventures |
Sources
Where this comes from
Reported by 5 sources.
Questions
Frequently asked
How much did Mainspring Energy raise in its Series E round?
Mainspring Energy raised $150M in its Series E round, announced in May 2022.
Who led Mainspring Energy's Series E round?
Lightrock led it, with Khosla Ventures, Fine Structure Ventures, Princeville Capital, Lineage Ventures and Breakthrough Energy.
What was Mainspring Energy's valuation at the Series E round?
It was not disclosed; its last disclosed one was $440M at the Series D (May 2021).
Did Mainspring Energy raise again after this round?
Yes: a Series F round in Apr 2025 of $258M.