MAINSPRING·Distributed / on-site power generation (dispatchable generators; alternative to gensets, gas turbines, and fuel cells)Pre-IPO · Private

Mainspring Energy

ConvictionContext

Hardware manufacturer of modular linear-generator power systems (250 kW to 100+ MW), sold direct and via power-infrastructure resellers, plus project-finance/unit-purchase agreements with utilities and Fortune-500 customers; pre-profit, VC-and-strategic-funded scale-up.

Revenue

not disclosedprivate; commercial shipments began 2020, 'hundreds of MW' in field operations and development

Rev growth

not disclosed

Gross margin

not disclosed

Op margin

not disclosedpre-profit scale-up; capital deployed to manufacturing expansion

Capex intensity

High - Series F proceeds explicitly earmarked for manufacturing capacity expansionhardware business with factory build-out

Valuation

~$451M-$661Mthird-party PitchBook estimate as of Nov 26, 2024, pre-Series F); Series F raised $258M in Apr 2025 led by General Catalyst at an undisclosed post-money valuation; >$800M raised to date (~$849M cumulative across 36 investors per PitchBook). Private - no public market cap.

Valuation trail

Series F - $258M led by General Catalyst; post-money undisclosed, implied low-single-digit billions consistent with the >$800M cumulative raise and data-center demand repricing2.7× since Nov 2024

2 marks · Nov 2024–Apr 2025

private — no public price

Priced round Secondary / SPAC mark

Mainspring does not disclose round valuations. The Nov 2024 point is a third-party PitchBook estimate; the Apr 2025 Series F point uses a disclosed $258M raise but an UNDISCLOSED post-money - the 1.5B figure is an implied estimate anchored to the dossier's low-single-digit-billions base case, not a reported number.

The read

Where our coverage leans

Coverage leans bullish

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Full financial intelligence for Mainspring Energy

Earnings, margins & COGS, the income-statement breakdown, SWOT, moats & dependencies, the supplier–customer ecosystem graph, top signals & trends, and the valuation range.

Income statement & margin structure
SWOT, moats & dependency map
Supplier–customer ecosystem graph
Signals, trends & valuation range

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