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Rewbi

YC S24

San Francisco, US · Founded 2024 · 3 employees · 12 known investors

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Rewbi rebuilds the electrical grid by financing, optimizing, and maintaining clean energy sources, particularly battery systems for grid stabilization. The company serves the power industry to reduce emissions and increase grid reliability.

Advanced ManufacturingAI & Machine LearningCleantechEnergyB2BRenewable EnergyCloud ComputingClimateTechUnited States of AmericaAmerica / Canada

Founders & leadership· Y Combinator alumni (S24)

Rewbi was founded in 2024 by Thomas Marge and Derek Modzelewski.

TMThomas Marge
Thomas MargeCo-Founder and CEOThomas Marge co-founded and leads Rewbi, an AI-powered battery storage optimization platform. Previously, he founded inBalance, a YC-backed company acquired by Stem in 2023, where he led battery storage optimization and forecasting; he also holds graduate degrees in applied and pure mathematics from Johns Hopkins University and completed doctoral work in pure mathematics at Cambridge.30 Under 30 2026
DMDerek Modzelewski
Derek ModzelewskiCo-Founder and CTODerek Modzelewski previously worked as an ML engineer at Meta on foundation models and served as an early technical hire at Adept, where he developed AI models. He holds a Master's degree in Computer Science and a B.S.E. in Computer Science and Applied Mathematics from Johns Hopkins University, and has roughly a decade of experience in energy commodity trading.30 Under 30 2026

Investors · 12

Collaborative Fundlisted by Collaborative FundNew York · $500K – $1M

How we know: Y Combinator's founder network · collabfund.com · Not right? Tell us

Maiora Rebel Ventureslisted by Maiora Rebel Ventures

How we know: Y Combinator's founder network · Not right? Tell us

Olive Tree Capitallisted by Olive Tree CapitalBoston

How we know: Olive Tree Capital's portfolio page · the VCSheet dataset · Y Combinator's founder network · Not right? Tell us

Rebel Fundlisted by Rebel FundSan Francisco · $100K – $5M

How we know: Y Combinator's founder network · rebelfund.vc · Not right? Tell us

SurgePoint Angellisted by SurgePoint AngelNew York

How we know: Y Combinator's founder network · Not right? Tell us

Y Combinatorlisted by Y CombinatorSan Francisco · $500K

How we know: the Y Combinator directory · open dataset · 5k.vc investor directory · Not right? Tell us

Agrolimen Venturesreported

How we know: Y Combinator's founder network · Not right? Tell us

General CatalystreportedSan Francisco · $30M

How we know: Y Combinator's founder network · Not right? Tell us

Great Wave VenturesreportedNew York · $250K – $1M

How we know: Y Combinator's founder network · open dataset · 5k.vc investor directory · Not right? Tell us

Orange CollectivereportedDanville

How we know: Y Combinator's founder network · Not right? Tell us

Sand Hill North VenturesreportedMontreal

How we know: Y Combinator's founder network · Not right? Tell us

Funding

SEC filings, press & company announcements

Source: company announcements and press reports — follow each round's link for the claim.

Related companies · 5

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Rise ReformingRise Reforming converts stranded biogas from wastewater plants, farms, and landfills into valuable chemicals including dimethyl ether (DME), methanol, and dimethyl carbonate (DMC) using modular, containerized technology. The company serves the chemical industry, offering a low-carbon alternative to fossil fuel-dependent chemical production with domestic feedstock security.
Line.BuildLine.Build provides a platform that helps energy efficiency contractors locate and apply for financing options and rebates by aggregating fragmented incentive programs from utilities, government sources, and private lenders. The software aims to simplify access to funding for building retrofits that reduce energy consumption and emissions.
RUUFRUUF is a solar panel installation and energy service company serving residential customers in Chile. The company handles the full process from evaluation and design to installation, certification, connection, and ongoing monitoring.

Companies working in the same space as Rewbi.

Legal entities · 1

corporate structure
Rewbi, Inc.

In the news

Rewbi Closes $4m Seed Roundrewbi.com · Apr 2025Rewbi - Using AI to optimize grid-connected battery storageycombinator.com · Aug 2024

Frequently asked questions

What does Rewbi do?
Rewbi rebuilds the electrical grid by financing, optimizing, and maintaining clean energy sources, particularly battery systems for grid stabilization. The company serves the power industry to reduce emissions and increase grid reliability.
Who founded Rewbi?
Rewbi was founded by Thomas Marge, Derek Modzelewski in 2024.
Who are Rewbi's investors?
Rewbi's investors include Aera VC, Collaborative Fund, Maiora Rebel Ventures, Olive Tree Capital, Rebel Fund, SurgePoint Angel, Y Combinator, Agrolimen Ventures and 4 more.
Where is Rewbi headquartered?
Rewbi is headquartered in San Francisco, US.