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Bedford, MA, USA · Private · fourthpower.com
High-temperature thermal storage in liquid tin with thermophotovoltaic conversion
Open roles
2
counted 2026-11-09
Federal awards
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none found
Last private raise
—
no Form D on file
SEC filings
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not an SEC filer
Coming up
POLICY45Y / 48E: all other clean power and storage
Full credit for projects beginning construction through 2033; 75% for 2034 starts, 50% for 2035, none from 2036. Affects Long-duration storage.
+ THESISHow it works
Cheap electricity heats bricks or carbon blocks to well over 1,000°C. The stored heat comes back out as factory heat or steam hours later.
OPEN IN 3D →Others on this approach
No public filings, raises or hiring trend to read yet.
Read from SEC 8-Ks (bankruptcy, default, delisting, restatement, impairment, restructuring), cash runway in annual reports, Form D raises and the 30-day hiring trend. A prompt to look closer, not a credit rating.
2026-11-042026-11-09
By team
By location
Sources: company job boards (daily), SEC EDGAR, USAspending.gov, and the reviewed technology spreadsheets. Public records only cover US entities, so foreign companies and private firms that don't file will show gaps.
No federal grants, contracts or loans found on USAspending.gov under this company's US entity name.
Policy that applies
No minerals, policies or partners linked yet. Add them in the review spreadsheet.
Not an SEC filer, or no US entity matched. Most private and foreign companies don't file.