Fourth Power vs Plus Power
Fourth Power
Energy Storage that Grows with the Grid
35 employees · est. 2021 · Cambridge, United States
Plus Power
Plus Power develops battery energy storage systems that enable a more efficient and reliable electrical grid
228 employees · est. 2018 · San Francisco, United States
Plus Power is the older company (2021 vs 2018); Plus Power is the larger of the two.
Side-by-Side Comparison
| Metric | Fourth Power | Plus Power |
|---|---|---|
| Founded | ||
| Founded | 2021 | 2018 older |
| Headquarters | ||
| Headquarters | Cambridge, United States | San Francisco, United States |
| Employees | ||
| Employees | 35 | 228 larger |
| Industry | ||
| Industry | Energy, Renewable Energy, Energy Storage | Energy, Renewable Energy, Energy Storage |
| Funding Stage | ||
| Funding Stage | Series A | Debt Financing |
| Total Funding | ||
| Total Funding | $19.00M | $2.12B |
| Funding Rounds | ||
| Funding Rounds | 1 | 3 |
| Services | ||
| Services | Thermal energy storage systems, Utility-scale energy solutions, Flexible grid-scale storage solutions | Not tracked yet |
| Target Customers | ||
| Target Customers | Utility companies, Energy infrastructure developers, Renewable energy sectors, Government energy agencies | Not tracked yet |
| Taxonomy | ||
| Taxonomy | Thermal BatteryEnergy StorageGrid StorageThermal StorageUtility-Scale StorageLong-Duration Energy Storage +8 | Battery Energy StorageElectrical Grid EfficiencyUtility-scale Energy StorageEnergy Storage ProjectsTransmission-connected Battery StorageElectric Utility Partnerships +7 |
| Website | ||
| Website | gofourth.com | pluspower.com |
About Fourth Power
Fourth Power is making significant strides in the energy sector with its innovative thermal battery technology. Founded in 2021 and headquartered in the United States, the company focuses on transforming renewable energy into an on-demand source via utility-scale thermal storage. These technological...
About Plus Power
Plus Power is a US-based startup founded in 2018 that focuses on developing battery energy storage systems. The company's slogan, "Plus Power develops battery energy storage systems that enable a more efficient and reliable electrical grid," encapsulates its core mission. Led by seasoned executives...
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Compiled from the BounceWatch company index. We last looked at Fourth Power on 18 Aug 2025, and Plus Power on 12 Sep 2024. Where a field is blank here, it means we have not recorded it — not that the answer is zero. How we source and date this.
