Mainspring Energy valuation, funding and investors
Mainspring Energy works in linear generator manufacturing, based in Menlo Park, United States. Founded in 2010, it has about 526 employees.
Electric Supplies & Power Generation Series F
VALUATION · TODAY
$4.28B −0% after Series F
Range $1.74B – $6.08B · Grade CTODAY
+12 MO
$2.00B
$4.00B
$6.00B
$8.00B
2011
2013
2015
2017
2019
2021
2023
2025
2027
Series C $83.0M
Series D $95.0M
Series E $150M
Series F $258M
ValuationBefore first round12-month outlook: where it points, how wide it fansHover the past: the outlook shows what was predicted then
HEADCOUNT · TODAY526 employees
+1%6m growth
+2%1y growth
+28%2y growth
200
400
600
Data from Jan 2021
Predicted in 1 yr $4.28B −0% vs today
Predicted next raise $471M if a round comes
Winding-down probability 0%
- Last round
- Series F · $258M · Apr 2025
- Valuation at last round
- $3.20B · implied
- Headcount
- 526 · flat
- Grade
- C
- Founded
- 2010
Mainspring Energy valuation today
VCMC values Mainspring Energy at $4.3B today, with a range of $1.7B to $6.1B and a grade of C. The valuation starts from its last funding round, a Series F round in Apr 2025.
Valuation by date (207 rows)
Each point is what the model would have shown on that date, using only what was known then; before its first round, a company is valued as a startup because it later raised.
| Date | Valuation | Range | Predicted in 1 yr | Phase | Headcount | Trend | Grade | Winding-down probability |
|---|---|---|---|---|---|---|---|---|
| 1 Jan 2010 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Feb 2010 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Mar 2010 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Apr 2010 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 May 2010 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Jun 2010 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Jul 2010 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Aug 2010 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Sep 2010 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Oct 2010 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Nov 2010 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Dec 2010 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Jan 2011 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Feb 2011 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Mar 2011 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Apr 2011 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 May 2011 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Jun 2011 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Jul 2011 | $4.97M | $1.81M – $13.7M | $4.97M (0%) | before first round | – | unknown | D | 0% |
| 1 Aug 2011 | $4.97M | $1.81M – $13.7M | $4.99M (0%) | before first round | – | unknown | D | 0% |
| 1 Sep 2011 | $4.97M | $1.81M – $13.7M | $5.01M (+1%) | before first round | – | unknown | D | 0% |
| 1 Oct 2011 | $4.97M | $1.81M – $13.7M | $5.03M (+1%) | before first round | – | unknown | D | 0% |
| 1 Nov 2011 | $4.97M | $1.81M – $13.7M | $5.05M (+2%) | before first round | – | unknown | D | 0% |
| 1 Dec 2011 | $4.97M | $1.81M – $13.7M | $5.07M (+2%) | before first round | – | unknown | D | 0% |
| 1 Jan 2012 | $4.97M | $1.81M – $13.7M | $5.09M (+2%) | before first round | – | unknown | D | 0% |
| 1 Feb 2012 | $4.97M | $1.81M – $13.7M | $5.11M (+3%) | before first round | – | unknown | D | 0% |
| 1 Mar 2012 | $4.97M | $1.81M – $13.7M | $5.13M (+3%) | before first round | – | unknown | D | 0% |
| 1 Apr 2012 | $4.97M | $1.81M – $13.7M | $5.15M (+4%) | before first round | – | unknown | D | 0% |
| 1 May 2012 | $4.97M | $1.81M – $13.7M | $5.17M (+4%) | before first round | – | unknown | D | 0% |
| 1 Jun 2012 | $4.97M | $1.81M – $13.7M | $5.19M (+4%) | before first round | – | unknown | D | 0% |
| 1 Jul 2012 | $4.97M | $1.81M – $13.7M | $5.21M (+5%) | before first round | – | unknown | D | 0% |
| 1 Aug 2012 | $4.99M | $1.82M – $13.7M | $5.23M (+5%) | before first round | – | unknown | D | 0% |
| 1 Sep 2012 | $5.01M | $1.83M – $13.8M | $5.25M (+5%) | before first round | – | unknown | D | 0% |
| 1 Oct 2012 | $5.03M | $1.83M – $13.8M | $5.27M (+5%) | before first round | – | unknown | D | 0% |
| 1 Nov 2012 | $5.05M | $1.84M – $13.9M | $5.30M (+5%) | before first round | – | unknown | D | 0% |
| 1 Dec 2012 | $5.07M | $1.85M – $13.9M | $5.32M (+5%) | before first round | – | unknown | D | 0% |
| 1 Jan 2013 | $5.09M | $1.85M – $14.0M | $5.34M (+5%) | before first round | – | unknown | D | 0% |
| 1 Feb 2013 | $5.11M | $1.86M – $14.0M | $5.36M (+5%) | before first round | – | unknown | D | 0% |
| 1 Mar 2013 | $5.13M | $1.87M – $14.1M | $5.38M (+5%) | before first round | – | unknown | D | 0% |
| 1 Apr 2013 | $5.15M | $1.88M – $14.2M | $5.40M (+5%) | before first round | – | unknown | D | 0% |
| 1 May 2013 | $5.17M | $1.88M – $14.2M | $5.42M (+5%) | before first round | – | unknown | D | 0% |
| 1 Jun 2013 | $5.19M | $1.89M – $14.3M | $5.44M (+5%) | before first round | – | unknown | D | 0% |
| 1 Jul 2013 | $5.21M | $1.90M – $14.3M | $5.46M (+5%) | before first round | – | unknown | D | 0% |
| 1 Aug 2013 | $5.23M | $1.91M – $14.4M | $5.48M (+5%) | before first round | – | unknown | D | 0% |
| 1 Sep 2013 | $5.25M | $1.91M – $14.4M | $5.51M (+5%) | before first round | – | unknown | D | 0% |
| 1 Oct 2013 | $5.27M | $1.92M – $14.5M | $5.53M (+5%) | before first round | – | unknown | D | 0% |
| 1 Nov 2013 | $5.30M | $1.93M – $14.5M | $5.55M (+5%) | before first round | – | unknown | D | 0% |
| 1 Dec 2013 | $5.32M | $1.94M – $14.6M | $5.57M (+5%) | before first round | – | unknown | D | 0% |
| 1 Jan 2014 | $5.34M | $1.94M – $14.7M | $5.59M (+5%) | before first round | – | unknown | D | 0% |
| 1 Feb 2014 | $5.36M | $1.95M – $14.7M | $5.62M (+5%) | before first round | – | unknown | D | 0% |
| 1 Mar 2014 | $5.38M | $1.96M – $14.8M | $5.64M (+5%) | before first round | – | unknown | D | 0% |
| 1 Apr 2014 | $5.40M | $1.97M – $14.8M | $5.66M (+5%) | before first round | – | unknown | D | 0% |
| 1 May 2014 | $5.42M | $1.97M – $14.9M | $5.68M (+5%) | before first round | – | unknown | D | 0% |
| 1 Jun 2014 | $5.44M | $1.98M – $14.9M | $5.70M (+5%) | before first round | – | unknown | D | 0% |
| 1 Jul 2014 | $5.46M | $1.99M – $15.0M | $5.72M (+5%) | before first round | – | unknown | D | 0% |
| 1 Aug 2014 | $5.48M | $2.00M – $15.1M | $5.75M (+5%) | before first round | – | unknown | D | 0% |
| 1 Sep 2014 | $5.51M | $2.00M – $15.1M | $5.77M (+5%) | before first round | – | unknown | D | 0% |
| 1 Oct 2014 | $5.53M | $2.01M – $15.2M | $5.79M (+5%) | before first round | – | unknown | D | 0% |
| 1 Nov 2014 | $5.55M | $2.02M – $15.2M | $5.82M (+5%) | before first round | – | unknown | D | 0% |
| 1 Dec 2014 | $5.57M | $2.03M – $15.3M | $5.84M (+5%) | before first round | – | unknown | D | 0% |
| 1 Jan 2015 | $5.59M | $2.04M – $15.4M | $5.86M (+5%) | before first round | – | unknown | D | 0% |
| 1 Feb 2015 | $5.62M | $2.04M – $15.4M | $5.88M (+5%) | before first round | – | unknown | D | 0% |
| 1 Mar 2015 | $5.64M | $2.05M – $15.5M | $5.91M (+5%) | before first round | – | unknown | D | 0% |
| 1 Apr 2015 | $5.66M | $2.06M – $15.5M | $5.93M (+5%) | before first round | – | unknown | D | 0% |
| 1 May 2015 | $5.68M | $2.07M – $15.6M | $5.95M (+5%) | before first round | – | unknown | D | 0% |
| 1 Jun 2015 | $5.70M | $2.08M – $15.7M | $5.98M (+5%) | before first round | – | unknown | D | 0% |
| 1 Jul 2015 | $5.72M | $2.08M – $15.7M | $6.00M (+5%) | before first round | – | unknown | D | 0% |
| 1 Aug 2015 | $5.75M | $2.09M – $15.8M | $6.15M (+7%) | before first round | – | unknown | D | 0% |
| 1 Sep 2015 | $5.77M | $2.10M – $15.8M | $6.32M (+10%) | before first round | – | unknown | D | 0% |
| 1 Oct 2015 | $5.79M | $2.11M – $15.9M | $6.49M (+12%) | before first round | – | unknown | D | 0% |
| 1 Nov 2015 | $5.82M | $2.12M – $16.0M | $6.66M (+15%) | before first round | – | unknown | D | 0% |
| 1 Dec 2015 | $5.84M | $2.13M – $16.0M | $6.84M (+17%) | before first round | – | unknown | D | 0% |
| 1 Jan 2016 | $5.86M | $2.13M – $16.1M | $7.03M (+20%) | before first round | – | unknown | D | 0% |
| 1 Feb 2016 | $5.88M | $2.14M – $16.2M | $7.22M (+23%) | before first round | – | unknown | D | 0% |
| 1 Mar 2016 | $5.91M | $2.15M – $16.2M | $7.40M (+25%) | before first round | – | unknown | D | 0% |
| 1 Apr 2016 | $5.93M | $2.16M – $16.3M | $7.60M (+28%) | before first round | – | unknown | D | 0% |
| 1 May 2016 | $5.95M | $2.17M – $16.4M | $7.80M (+31%) | before first round | – | unknown | D | 0% |
| 1 Jun 2016 | $5.98M | $2.18M – $16.4M | $8.01M (+34%) | before first round | – | unknown | D | 0% |
| 1 Jul 2016 | $6.00M | $2.18M – $16.5M | $8.22M (+37%) | before first round | – | unknown | D | 0% |
| 1 Aug 2016 | $6.16M | $2.24M – $16.9M | $8.44M (+37%) | before first round | – | unknown | D | 0% |
| 1 Sep 2016 | $6.33M | $2.30M – $17.4M | $8.67M (+37%) | before first round | – | unknown | D | 0% |
| 1 Oct 2016 | $6.49M | $2.36M – $17.8M | $8.90M (+37%) | before first round | – | unknown | D | 0% |
| 1 Nov 2016 | $6.67M | $2.43M – $18.3M | $9.14M (+37%) | before first round | – | unknown | D | 0% |
| 1 Dec 2016 | $6.84M | $2.49M – $18.8M | $9.38M (+37%) | before first round | – | unknown | D | 0% |
| 1 Jan 2017 | $7.03M | $2.56M – $19.3M | $9.63M (+37%) | before first round | – | unknown | D | 0% |
| 1 Feb 2017 | $7.22M | $2.63M – $19.8M | $9.89M (+37%) | before first round | – | unknown | D | 0% |
| 1 Mar 2017 | $7.39M | $2.69M – $20.3M | $10.1M (+37%) | before first round | – | unknown | D | 0% |
| 1 Apr 2017 | $7.59M | $2.76M – $20.9M | $10.4M (+37%) | before first round | – | unknown | D | 0% |
| 1 May 2017 | $7.79M | $2.84M – $21.4M | $10.7M (+37%) | before first round | – | unknown | D | 0% |
| 1 Jun 2017 | $8.00M | $2.91M – $22.0M | $11.0M (+37%) | before first round | – | unknown | D | 0% |
| 1 Jul 2017 | $8.21M | $2.99M – $22.6M | $11.3M (+37%) | before first round | – | unknown | D | 0% |
| 1 Aug 2017 | $8.44M | $3.07M – $23.2M | $11.6M (+37%) | before first round | – | unknown | D | 0% |
| 1 Sep 2017 | $8.67M | $3.15M – $23.8M | $11.9M (+37%) | before first round | – | unknown | D | 0% |
| 1 Oct 2017 | $8.89M | $3.24M – $24.4M | $12.2M (+37%) | before first round | – | unknown | D | 0% |
| 1 Nov 2017 | $9.14M | $3.33M – $25.1M | $12.5M (+37%) | before first round | – | unknown | D | 0% |
| 1 Dec 2017 | $9.37M | $3.41M – $25.8M | $12.9M (+37%) | before first round | – | unknown | D | 0% |
| 1 Jan 2018 | $9.63M | $3.51M – $26.5M | $13.2M (+37%) | before first round | – | unknown | D | 0% |
| 25 Jan 2018 | $755M | $496M – $1.5B | $981M (+30%) | after a round | – | unknown | B | 0% |
| 1 Feb 2018 | $759M | $496M – $1.5B | $981M (+29%) | after a round | – | unknown | B | 0% |
| 1 Mar 2018 | $774M | $496M – $1.5B | $981M (+27%) | after a round | – | unknown | B | 0% |
| 1 Apr 2018 | $792M | $496M – $1.5B | $981M (+24%) | after a round | – | unknown | B | 0% |
| 1 May 2018 | $809M | $496M – $1.5B | $981M (+21%) | after a round | – | unknown | B | 0% |
| 1 Jun 2018 | $827M | $496M – $1.5B | $981M (+19%) | after a round | – | unknown | B | 0% |
| 1 Jul 2018 | $845M | $496M – $1.5B | $981M (+16%) | after a round | – | unknown | B | 0% |
| 1 Aug 2018 | $864M | $496M – $1.5B | $981M (+13%) | after a round | – | unknown | B | 0% |
| 1 Sep 2018 | $884M | $496M – $1.5B | $981M (+11%) | after a round | – | unknown | B | 0% |
| 1 Oct 2018 | $903M | $496M – $1.5B | $981M (+9%) | after a round | – | unknown | B | 0% |
| 1 Nov 2018 | $923M | $496M – $1.5B | $981M (+6%) | after a round | – | unknown | B | 0% |
| 1 Dec 2018 | $943M | $496M – $1.5B | $981M (+4%) | after a round | – | unknown | B | 0% |
| 1 Jan 2019 | $965M | $496M – $1.5B | $981M (+2%) | after a round | – | unknown | B | 0% |
| 1 Feb 2019 | $981M | $490M – $1.5B | $981M (0%) | after a round | – | unknown | B | 0% |
| 1 Mar 2019 | $981M | $470M – $1.5B | $981M (0%) | after a round | – | unknown | B | 0% |
| 1 Apr 2019 | $981M | $449M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 May 2019 | $981M | $429M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 Jun 2019 | $981M | $409M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 Jul 2019 | $981M | $392M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 Aug 2019 | $981M | $374M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 Sep 2019 | $981M | $357M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 Oct 2019 | $981M | $341M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 Nov 2019 | $981M | $326M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 Dec 2019 | $981M | $311M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 Jan 2020 | $981M | $297M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 Feb 2020 | $981M | $269M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 Mar 2020 | $981M | $256M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 Apr 2020 | $981M | $244M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 May 2020 | $981M | $232M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 Jun 2020 | $981M | $220M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 Jul 2020 | $981M | $210M – $1.5B | $981M (0%) | after a round | – | unknown | C | 0% |
| 1 Aug 2020 | $981M | $199M – $1.5B | $981M (0%) | after a round | – | unknown | D | 0% |
| 1 Sep 2020 | $981M | $189M – $1.5B | $981M (0%) | after a round | – | unknown | D | 0% |
| 1 Oct 2020 | $981M | $180M – $1.5B | $981M (0%) | after a round | – | unknown | D | 0% |
| 1 Nov 2020 | $981M | $171M – $1.5B | $981M (0%) | after a round | – | unknown | D | 0% |
| 1 Dec 2020 | $981M | $163M – $1.5B | $981M (0%) | after a round | – | unknown | D | 0% |
| 1 Jan 2021 | $981M | $155M – $1.5B | $981M (0%) | after a round | 110 | unknown | D | 0% |
| 1 Feb 2021 | $981M | $147M – $1.5B | $981M (0%) | after a round | 110 | unknown | D | 0% |
| 1 Mar 2021 | $981M | $141M – $1.5B | $981M (0%) | after a round | 110 | unknown | D | 0% |
| 1 Apr 2021 | $963M | $134M – $1.5B | $871M (-10%) | after a round | 110 | flat | D | 0% |
| 1 May 2021 | $955M | $127M – $1.5B | $864M (-10%) | after a round | 110 | flat | D | 0% |
| 5 May 2021 | $441M | $383M – $658M | $572M (+30%) | after a round | 110 | flat | A | 0% |
| 1 Jun 2021 | $449M | $383M – $658M | $572M (+27%) | after a round | 110 | flat | A | 0% |
| 1 Jul 2021 | $459M | $383M – $658M | $572M (+25%) | after a round | 110 | flat | A | 0% |
| 1 Aug 2021 | $469M | $383M – $658M | $572M (+22%) | after a round | 110 | flat | A | 0% |
| 1 Sep 2021 | $480M | $383M – $658M | $572M (+19%) | after a round | 110 | flat | A | 0% |
| 1 Oct 2021 | $490M | $383M – $658M | $572M (+17%) | after a round | 110 | flat | A | 0% |
| 1 Nov 2021 | $501M | $383M – $658M | $572M (+14%) | after a round | 110 | flat | A | 0% |
| 1 Dec 2021 | $512M | $383M – $658M | $572M (+12%) | after a round | 110 | flat | A | 0% |
| 1 Jan 2022 | $524M | $383M – $658M | $572M (+9%) | after a round | 110 | flat | A | 0% |
| 1 Feb 2022 | $591M | $383M – $751M | $653M (+10%) | after a round | 200 | growing | B | 0% |
| 1 Mar 2022 | $609M | $383M – $751M | $653M (+7%) | after a round | 200 | growing | B | 0% |
| 1 Apr 2022 | $630M | $383M – $751M | $653M (+4%) | after a round | 200 | growing | B | 0% |
| 1 May 2022 | $651M | $383M – $751M | $653M (0%) | after a round | 200 | growing | B | 0% |
| 25 May 2022 | $1.3B | $938M – $2.5B | $1.7B (+30%) | after a round | 200 | growing | B | 0% |
| 1 Jun 2022 | $1.3B | $938M – $2.5B | $1.7B (+29%) | after a round | 200 | growing | B | 0% |
| 1 Jul 2022 | $1.4B | $938M – $2.5B | $1.7B (+26%) | after a round | 200 | growing | B | 0% |
| 1 Aug 2022 | $1.4B | $938M – $2.5B | $1.7B (+24%) | after a round | 200 | growing | B | 0% |
| 1 Sep 2022 | $1.4B | $938M – $2.5B | $1.7B (+21%) | after a round | 200 | growing | B | 0% |
| 1 Oct 2022 | $1.5B | $938M – $2.5B | $1.7B (+18%) | after a round | 200 | growing | B | 0% |
| 1 Nov 2022 | $1.5B | $938M – $2.5B | $1.7B (+16%) | after a round | 200 | unknown | B | 0% |
| 1 Dec 2022 | $1.5B | $938M – $2.5B | $1.7B (+13%) | after a round | 200 | unknown | B | 0% |
| 1 Jan 2023 | $1.6B | $938M – $2.5B | $1.7B (+11%) | after a round | 200 | unknown | B | 0% |
| 1 Feb 2023 | $1.6B | $938M – $2.5B | $1.7B (+8%) | after a round | 200 | unknown | B | 0% |
| 1 Mar 2023 | $1.6B | $938M – $2.5B | $1.7B (+6%) | after a round | 200 | unknown | B | 0% |
| 1 Apr 2023 | $1.8B | $1.0B – $2.7B | $1.9B (+5%) | after a round | 310 | growing | B | 0% |
| 1 May 2023 | $1.9B | $1.0B – $2.7B | $1.9B (+2%) | after a round | 310 | growing | B | 0% |
| 1 Jun 2023 | $1.9B | $1.0B – $2.7B | $1.9B (0%) | after a round | 310 | growing | B | 0% |
| 1 Jul 2023 | $1.9B | $1.0B – $2.7B | $1.9B (0%) | after a round | 310 | growing | B | 0% |
| 1 Aug 2023 | $1.9B | $1.0B – $2.7B | $1.9B (0%) | after a round | 310 | growing | B | 0% |
| 1 Sep 2023 | $1.9B | $890M – $2.7B | $1.9B (0%) | after a round | 310 | unknown | B | 0% |
| 1 Oct 2023 | $1.9B | $868M – $2.8B | $1.9B (0%) | after a round | 340 | flat | B | 0% |
| 1 Nov 2023 | $1.9B | $829M – $2.8B | $1.9B (0%) | after a round | 340 | flat | C | 0% |
| 1 Dec 2023 | $1.9B | $793M – $2.8B | $1.9B (0%) | after a round | 340 | flat | C | 0% |
| 1 Jan 2024 | $1.9B | $757M – $2.8B | $1.9B (0%) | after a round | 340 | flat | C | 0% |
| 1 Feb 2024 | $2.0B | $980M – $2.8B | $2.0B (0%) | after a round | 370 | up | B | 0% |
| 1 Mar 2024 | $2.0B | $975M – $2.8B | $2.0B (0%) | after a round | 380 | up | B | 0% |
| 1 Apr 2024 | $2.0B | $965M – $2.8B | $2.0B (0%) | after a round | 380 | up | B | 0% |
| 1 May 2024 | $2.0B | $954M – $2.8B | $2.0B (0%) | after a round | 380 | up | B | 0% |
| 1 Jun 2024 | $2.0B | $859M – $2.8B | $2.0B (0%) | after a round | 380 | up | B | 0% |
| 1 Jul 2024 | $2.0B | $858M – $2.9B | $2.0B (0%) | after a round | 410 | up | C | 0% |
| 1 Aug 2024 | $2.0B | $842M – $2.9B | $2.0B (0%) | after a round | 410 | up | C | 0% |
| 1 Sep 2024 | $2.0B | $826M – $2.9B | $2.0B (0%) | after a round | 410 | up | C | 0% |
| 1 Oct 2024 | $2.0B | $811M – $2.9B | $2.0B (0%) | after a round | 410 | up | C | 0% |
| 1 Nov 2024 | $2.1B | $808M – $2.9B | $2.0B (-1%) | after a round | 440 | up | C | 0% |
| 1 Dec 2024 | $2.1B | $793M – $2.9B | $2.0B (-1%) | after a round | 440 | up | C | 0% |
| 1 Jan 2025 | $2.1B | $1.2B – $3.0B | $2.1B (0%) | after a round | 460 | growing | B | 0% |
| 1 Feb 2025 | $2.1B | $1.2B – $3.0B | $2.1B (0%) | after a round | 460 | growing | B | 0% |
| 1 Mar 2025 | $2.1B | $1.2B – $3.0B | $2.1B (0%) | after a round | 460 | growing | B | 0% |
| 1 Apr 2025 | $2.1B | $1.2B – $3.0B | $2.1B (0%) | after a round | 460 | growing | B | 0% |
| 15 Apr 2025 | $3.2B | $2.3B – $5.9B | $4.2B (+30%) | after a round | 460 | up | B | 0% |
| 1 May 2025 | $3.2B | $2.3B – $5.9B | $4.2B (+28%) | after a round | 460 | up | B | 0% |
| 1 Jun 2025 | $3.3B | $2.3B – $5.9B | $4.2B (+26%) | after a round | 460 | up | B | 0% |
| 1 Jul 2025 | $3.4B | $2.3B – $5.9B | $4.2B (+23%) | after a round | 460 | up | B | 0% |
| 1 Aug 2025 | $3.5B | $2.3B – $6.1B | $4.3B (+22%) | after a round | 515 | growing | B | 0% |
| 1 Sep 2025 | $3.6B | $2.3B – $6.1B | $4.3B (+19%) | after a round | 515 | growing | B | 0% |
| 1 Oct 2025 | $3.7B | $2.3B – $6.1B | $4.3B (+17%) | after a round | 515 | up | B | 0% |
| 1 Nov 2025 | $3.7B | $2.3B – $6.1B | $4.3B (+14%) | after a round | 516 | up | B | 0% |
| 1 Dec 2025 | $3.8B | $2.3B – $6.1B | $4.3B (+11%) | after a round | 516 | up | B | 0% |
| 1 Jan 2026 | $3.9B | $2.3B – $6.1B | $4.3B (+9%) | after a round | 523 | up | B | 0% |
| 1 Feb 2026 | $4.0B | $2.3B – $6.1B | $4.3B (+6%) | after a round | 523 | up | B | 0% |
| 1 Mar 2026 | $4.1B | $2.3B – $6.1B | $4.3B (+4%) | after a round | 523 | up | B | 0% |
| 1 Apr 2026 | $4.2B | $2.3B – $6.1B | $4.3B (+1%) | after a round | 523 | up | B | 0% |
| 1 May 2026 | $4.3B | $2.3B – $6.1B | $4.3B (0%) | after a round | 515 | up | B | 0% |
| 1 Jun 2026 | $4.3B | $2.3B – $6.1B | $4.3B (0%) | after a round | 515 | up | B | 0% |
| 1 Jul 2026 | $4.3B | $2.2B – $6.1B | $4.3B (0%) | after a round | 516 | up | B | 0% |
| 1 Aug 2026 | $4.3B | $2.0B – $6.1B | $4.3B (0%) | after a round | 516 | flat | B | 0% |
| 1 Sep 2026 | $4.3B | $1.9B – $6.1B | $4.3B (0%) | after a round | 516 | flat | B | 0% |
| 1 Oct 2026 | $4.3B | $1.8B – $6.1B | $4.3B (0%) | after a round | 526 | flat | C | 0% |
| 24 Oct 2026 | $4.3B | $1.7B – $6.1B | $4.3B (0%) | after a round | 526 | flat | C | 0% |
Key facts about Mainspring Energy
- Founded
- 2010
- Headquarters
- Menlo Park, United States
- Employees
- about 526 +2% in a year
- Total raised
- $673M
- Funding rounds
- 5
- Last round
- Series F Apr 2025
Mainspring Energy was founded in 2010 by Adam Simpson and Shannon Miller.
Mainspring Energy funding history
Mainspring Energy has 5 funding rounds on record, from Jan 2018 to Apr 2025, $673M in total. The latest disclosed valuation is $440M post-money (Series D, May 2021).
Series F 14 Apr 2025
Led by General Catalyst; with Amazon's Climate Pledge Fund, DCVC, Temasek, Marunouchi Innovation Partners, M&G Investments, Pictet Group, Lightrock, LGT Bank, Khosla Ventures, Gates Frontier.
Sources: mainspringenergy.com, prnewswire.com, fenwick.com and 1 more
$258M
Grant 22 Oct 2024no round page
With U.S. Department of Energy.
Sources: mainspringenergy.com, deluzio.house.gov, globaltradealert.org and 2 more
$87M
Series E 24 May 2022
Led by Lightrock; with Khosla Ventures, Fine Structure Ventures, Princeville Capital, Lineage Ventures, Breakthrough Energy. Individuals: Bill Gates.
Sources: mainspringenergy.com, prnewswire.com, axios.com and 2 more
$150M
Series D 4 May 2021
Led by Devonshire Investors; with Princeville Capital, 40 North Ventures, Chevron Technology Ventures, Khosla Ventures, ClearSky, AEP, KCK Financial Services, Equinor, Trog Hawley Capital, Alumni Ventures Group, Gates Frontier Fund, NextEra Energy. Individuals: Bill Gates.
Sources: mainspringenergy.com, prnewswire.com, fenwick.com and 2 more
$95M
$440M post-money
Series C 24 Jan 2018
With American Electric Power (AEP), Centrica Innovations, Statoil Energy Ventures, KCK Financial Services, Breakthrough Energy, Khosla Ventures.
Sources: prnewswire.com
$83M
Mainspring Energy investors
30 investors have backed Mainspring Energy; Lightrock, Devonshire Investors and General Catalyst led at least one round.
- Lightrock lead, 2 rounds
- Devonshire Investors lead
- General Catalyst lead
- Khosla Ventures 4 rounds
- Breakthrough Energy 2 rounds
- Princeville Capital 2 rounds
- 40 North Ventures
- AEP
- Alumni Ventures Group
- Amazon's Climate Pledge Fund
- American Electric Power (AEP)
- Centrica Innovations
- Chevron Technology Ventures
- ClearSky
- DCVC
- Equinor
- Gates Frontier
- Gates Frontier Fund
- LGT Bank
- Lineage Ventures
- M&G Investments
- Marunouchi Innovation Partners
- NextEra Energy
- Pictet Group
- Statoil Energy Ventures
- Temasek
- U.S. Department of Energy
What Mainspring Energy does
Mainspring Energy works in electric supplies & power generation, with 15 recorded offerings and customers in utilities, data centers, enterprise and industrial.
Mainspring Energy, Inc. is an American manufacturing company engaged in the design and production of linear generators for onsite power generation. The company develops modular, fuel-flexible electric generator systems that operate on natural gas, biogas, propane, field gas, associated gas, or hydrogen, and are capable of multi-fuel operation and seamless fuel switching. Mainspring Energy also provides related services such as site planning, financing, permitting, installation, and maintenance. Its solutions are designed for use in data centers, utilities, enterprise, and industrial sectors, with a focus on local power solutions for capacity-constrained companies and communities.
Description from Veridion's company data.
Products and services
- Linear Generator Manufacturing
- Modular Power System Design
- Fuel-Flexible Power Solution Development
- Low-NOx Power Solution Development
- Prime Power Solution Delivery
- Solar Firming Solution Delivery
- Diesel Reduction Solution Delivery
- Grid Services Solution Delivery
- Multi-Fuel Generator Integration
- Power System Site Planning Services
- Power System Financing Services
- Power System Permitting Services
- Power System Installation Services
- Power System Maintenance Services
- Electric Generator Technology Advancement
Markets
- Utilities
- Data Centers
- Enterprise
- Industrial
Technology
- Linear Generator Technology
- Fuel Flexible Power Generation
- Modular Generator Design
- Low-NOx Power Generation
Business model
- Business-to-Business
- Service Provider
- Manufacturing
- Enterprise
Industry codes (NAICS)
- 335312 Motor and Generator Manufacturing 70% match
- 238210 Electrical Contractors and Other Wiring Installation Contractors 15% match
- 811310 Commercial and Industrial Machinery and Equipment (except Automotive and Electronic) Repair and Maintenance 15% match
Questions about Mainspring Energy
What is Mainspring Energy worth?
Valuation $4.3B (range $1.7B to $6.1B), as of 24 Oct 2026. The last disclosed valuation was $440M (Series D, May 2021).
Has Mainspring Energy raised money?
Mainspring Energy has 5 funding rounds on record, from Jan 2018 to Apr 2025, $673M in total. The latest disclosed valuation is $440M post-money (Series D, May 2021).
Who has invested in Mainspring Energy?
Lightrock, Devonshire Investors, General Catalyst, Khosla Ventures, Breakthrough Energy and KCK Financial Services, and 24 more. Lead investors include Lightrock, Devonshire Investors and General Catalyst.
How many people work at Mainspring Energy?
About 526, up 2% over the last year. Headcount grew from 110 in Jan 2021 to 526 in Sep 2026.
What does Mainspring Energy do?
Mainspring Energy works in electric supplies & power generation, with 15 recorded offerings and customers in utilities, data centers, enterprise and industrial. Its main offerings are linear generator manufacturing, modular power system design and fuel-flexible power solution development.
When was Mainspring Energy founded, and where is it based?
Mainspring Energy was founded in 2010 and is based in Menlo Park, United States. It has about 526 employees, up 2% over the last year.