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Fourth Power

Fourth Power

Private
Cambridge, MassachusettsEnergy & Sustainabilityhttps://gofourth.com/

Last Round

Series A

Extension

Sep 16, 2025

Total Funding Raised

$44.11M

Company Overview

Fourth Power is a clean energy company that develops utility-scale thermal battery storage solutions to capture excess wind and solar energy for on-demand grid dispatch.

Sector

Energy & Sustainability

Verticals

Energy Storage, Renewable Energy, Smart Grid

Business Model

B2B

Customer Profile

Hardware Sales

AI Layer

Non-AI

Keywords

thermal energy storagelong-duration energy storageLDESthermal batterymolten tinthermophotovoltaicsTPVgrid-scale storageutility-scale storagegrid stabilityrenewable energy storagenon-lithium storagesci-fi batteriesenergy infrastructure

Historical Pricing

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Caplight Momentum Score

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Fourth Power Comparables

Compare Fourth Power with similar companies based on industry and business-model similarity.

Fourth Power comparables — related companies by embedding similarity
CompanySimilarityMarket Cap
Malta Inc
81%
Ambri
78%
MGA Thermal
77%

Fourth Power Funding Rounds

Historical fundraising activity

Data table
RoundDateAmount RaisedValuationInvestorsSources
Series A ExtensionSep 16, 2025
Series ADec 12, 2023
GrantFeb 27, 2023
GrantDec 18, 2018
GrantNov 28, 2012

Key People

Founding team and executive leadership

Asegun Henry

Founder CTO

Founding Team

Fourth Power Investors

Notable investors and investment history

Fourth Power investors
InvestorRounds
Munich Re VenturesSeries A Extension
Breakthrough Energy VenturesSeries A, Series A Extension
BVCCSeries A
Department of EnergyGrant
DCVC (Data Collective)Series A Extension, Series A

Market signals

Structured signals derived from secondary market and firmographic data.

  • Feb 27, 2023

    $10K grant received from the Department of Energy.

Recent news

Latest coverage and updates

  • expands_facilitiesSep 14, 2026

    Fourth Power, Inc. expanded facilities to Bedford, Massachusetts, United States, Northern America, Americas on Sep 14th '26.

Fourth Power Filings

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Fourth Power filings preview — column headings only; records require access
TypeDateAmount OfferedAmount SoldFilingPagesDownload

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Frequently Asked Questions

Common questions about Fourth Power's valuation, stock price, and market status.

Is Fourth Power a public or private company?

Fourth Power is a private company.

What is the current stock price of Fourth Power?

Fourth Power is a private company with no public stock price. No recent secondary market data is available.

How much is Fourth Power worth (valuation)?

Valuation information for Fourth Power is not publicly available.

Can I buy Fourth Power stock?

Fourth Power shares may be available on secondary markets subject to transfer restrictions. Caplight facilitates secondary market transactions for accredited investors. Visit https://www.caplight.com to learn more.

When was Fourth Power's last funding round?

Fourth Power's most recent funding round was Series A Extension on September 16, 2025.

Who are the main investors in Fourth Power?

Key investors in Fourth Power include Munich Re Ventures, Department of Energy, DCVC (Data Collective).

Will Fourth Power IPO soon?

No public IPO plans have been announced for Fourth Power.

How can I track Fourth Power secondary market activity?

Caplight tracks bids, offers, and trades for private companies. Visit https://www.caplight.com to monitor Fourth Power's secondary market activity and sign up for updates.

Firmographic Details

HeadquartersCambridge, Massachusetts
Employee Range28
Year Founded2021
Last FundingSep 16, 2025

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