Helping entrepreneursTransformindustry faster




They scale when entire ecosystems move together: founders, corporates, capital, policy, and communities, united by a shared purpose of propelling groundbreaking technologies to market, at the pace the world requires.
Transforming the systems that power, move, feed, and connect the world is the work of our time, and startups hold the key.
Greentown is a 501(c)(3) non-profit organization

Resolute Methane
Food, Water, & Land
Treating low-concentration methane emissions at the source by thermally oxidizing methane with a novel reactor design

String Data Motion
Infrastructure & Construction
Agentic AI for energy companies. Agents in motion. Outcomes delivered.

Thiozen
Manufacturing & Processing
Chemical waste-to-hydrogen cycle that removes hydrogen sulfide from gas streams and generates zero-emission hydrogen

SpringCycle Energy
Energy & Power
Rechargeable iron fuel to transform solar into baseload power

ATOM-X
Energy & Power
Transforming CO₂ into sustainable fuels like green methanol

Matterworks
Manufacturing & Processing
Enabling metabolomics assays that are fast, broad, and can characterize diverse chemical classes with a single setup

Mocean Energy
Energy & Power
Hybrid-offshore renewable power stations, combining wave, solar, and battery systems

Optigon
Energy & Power
Rapid, contactless characterization for assessing performance during photovoltaic solar cell fabrication

Corrolytics
Energy & Power
Corrosion detection through electrochemical innovation, integrated with advanced AI technology

Helix Earth Technologies
Infrastructure & Construction
Improving energy efficiency and minimizing emissions through a droplet-capture filtration system

Clarity Castle
Infrastructure & Construction
Modular, soundproof work pods made from recycled materials

Cemvita
Manufacturing & Processing
Engineered microbes to transform CO₂ and other wastes into valuable compounds, closing the carbon and waste loop

Ignition Packaging
About the Company Ignition Packaging is a biomaterials company developing scalable, cost-competitive alternatives to conventional petroleum-based foams. Ignition Packaging’s core technology transforms agricultural byproducts into a high-performance, biodegradable foam engineered […]

Infinite Foundry
Manufacturing & Processing
Real-time 3D operational models to improve efficiency, lower costs, and enhance sustainability

Solidec
Manufacturing & Processing
Converting carbon into chemicals using only air, water, and renewable electricity

QuantAQ
Infrastructure & Construction
Air quality-monitoring networks that combine IoT hardware, machine learning, and user-friendly software design

Terralytiq
Manufacturing & Processing
Digital models that deliver Scope 3 hotspots, actionable initiatives, and supplier engagement to cut cost and carbon

Enel (Member Account)
Energy & Power
One of the world’s leading integrated utilities and the largest private producer of clean energy

Anvil Capture Systems
Manufacturing & Processing
CO2 direct air mineralization process, delivering carbon dioxide removal

ThermaFuels
Transportation & Logistics
Deploying scalable, financeable low-carbon methanol and sustainable fuel infrastructure

Resolute Methane
Food, Water, & Land
Treating low-concentration methane emissions at the source by thermally oxidizing methane with a novel reactor design

String Data Motion
Infrastructure & Construction
Agentic AI for energy companies. Agents in motion. Outcomes delivered.

Thiozen
Manufacturing & Processing
Chemical waste-to-hydrogen cycle that removes hydrogen sulfide from gas streams and generates zero-emission hydrogen

SpringCycle Energy
Energy & Power
Rechargeable iron fuel to transform solar into baseload power

ATOM-X
Energy & Power
Transforming CO₂ into sustainable fuels like green methanol

Matterworks
Manufacturing & Processing
Enabling metabolomics assays that are fast, broad, and can characterize diverse chemical classes with a single setup

Mocean Energy
Energy & Power
Hybrid-offshore renewable power stations, combining wave, solar, and battery systems

Optigon
Energy & Power
Rapid, contactless characterization for assessing performance during photovoltaic solar cell fabrication

Corrolytics
Energy & Power
Corrosion detection through electrochemical innovation, integrated with advanced AI technology

Helix Earth Technologies
Infrastructure & Construction
Improving energy efficiency and minimizing emissions through a droplet-capture filtration system

Clarity Castle
Infrastructure & Construction
Modular, soundproof work pods made from recycled materials

Cemvita
Manufacturing & Processing
Engineered microbes to transform CO₂ and other wastes into valuable compounds, closing the carbon and waste loop

Ignition Packaging
About the Company Ignition Packaging is a biomaterials company developing scalable, cost-competitive alternatives to conventional petroleum-based foams. Ignition Packaging’s core technology transforms agricultural byproducts into a high-performance, biodegradable foam engineered […]

Infinite Foundry
Manufacturing & Processing
Real-time 3D operational models to improve efficiency, lower costs, and enhance sustainability

Solidec
Manufacturing & Processing
Converting carbon into chemicals using only air, water, and renewable electricity

QuantAQ
Infrastructure & Construction
Air quality-monitoring networks that combine IoT hardware, machine learning, and user-friendly software design

Terralytiq
Manufacturing & Processing
Digital models that deliver Scope 3 hotspots, actionable initiatives, and supplier engagement to cut cost and carbon

Enel (Member Account)
Energy & Power
One of the world’s leading integrated utilities and the largest private producer of clean energy

Anvil Capture Systems
Manufacturing & Processing
CO2 direct air mineralization process, delivering carbon dioxide removal

ThermaFuels
Transportation & Logistics
Deploying scalable, financeable low-carbon methanol and sustainable fuel infrastructure

Massachusetts Materials Technologies
Energy & Power
Seamlessly measuring the mechanical properties of pipelines without interruption

Swan Impact Network
Infrastructure & Construction
Angel investor network focusing on supporting early-stage companies

Carbon To Stone
Energy & Power
Carbon-mineralization technology with high-value minerals and metals recovery

Priority Investor Loans
Infrastructure & Construction
Simplified loan programs to fund real estate investors nationwide with income-producing properties

Arbon
Energy & Power
Low energy humidity-driven modular tech capturing and releasing CO2 for practical decarbonization

Torres Orbital Mining Inc (TOM)
Infrastructure & Construction
Autonomous lunar excavation systems for dust-free regolith mining and space operations

Rushnu
Manufacturing & Processing
Turns waste into carbon-neutral chemistry

Provocative
Manufacturing & Processing
Replacing data centers’ cooling systems with carbon capture

Allkemie
Manufacturing & Processing
Producing tailored graphene and other nanomaterials at scale

Anning Corporation
Energy & Power
Targeting iron-rich rocks to produce hydrogen

Lite-1
Manufacturing & Processing
Clean, scalable, microbe-made colour to replace toxic dyes

Realizse
Energy & Power
Tokenization and product verification for circularity, energy, and the real estate markets

Active Surfaces
Energy & Power
Flexible, lightweight solar panels that turn any surface into solar

Diffraqtion
Energy & Power
AI cameras powering ultra high-resolution Earth and Space imaging

Licube
Manufacturing & Processing
Sustainable lithium recovery through electrodialysis

SolarKal
Energy & Power
The largest solar energy marketplace in the U.S., connecting organizations to solar providers

FlowCellutions
Energy & Power
Preventing power outages and improving cost savings for critical battery systems

Browning the Green Space
Food, Water, & Land
Addressing diversity, equity, and inclusion across careers, companies, contracts, capital, and communities

SRGE
Infrastructure & Construction
Full-service accelerator to support small and underrepresented-led construction firms

Zero Homes
Infrastructure & Construction
Automated assessment, design, and procurement platform for residential building retrofits

Massachusetts Materials Technologies
Energy & Power
Seamlessly measuring the mechanical properties of pipelines without interruption

Swan Impact Network
Infrastructure & Construction
Angel investor network focusing on supporting early-stage companies

Carbon To Stone
Energy & Power
Carbon-mineralization technology with high-value minerals and metals recovery

Priority Investor Loans
Infrastructure & Construction
Simplified loan programs to fund real estate investors nationwide with income-producing properties

Arbon
Energy & Power
Low energy humidity-driven modular tech capturing and releasing CO2 for practical decarbonization

Torres Orbital Mining Inc (TOM)
Infrastructure & Construction
Autonomous lunar excavation systems for dust-free regolith mining and space operations

Rushnu
Manufacturing & Processing
Turns waste into carbon-neutral chemistry

Provocative
Manufacturing & Processing
Replacing data centers’ cooling systems with carbon capture

Allkemie
Manufacturing & Processing
Producing tailored graphene and other nanomaterials at scale

Anning Corporation
Energy & Power
Targeting iron-rich rocks to produce hydrogen

Lite-1
Manufacturing & Processing
Clean, scalable, microbe-made colour to replace toxic dyes

Realizse
Energy & Power
Tokenization and product verification for circularity, energy, and the real estate markets

Active Surfaces
Energy & Power
Flexible, lightweight solar panels that turn any surface into solar

Diffraqtion
Energy & Power
AI cameras powering ultra high-resolution Earth and Space imaging

Licube
Manufacturing & Processing
Sustainable lithium recovery through electrodialysis

SolarKal
Energy & Power
The largest solar energy marketplace in the U.S., connecting organizations to solar providers

FlowCellutions
Energy & Power
Preventing power outages and improving cost savings for critical battery systems

Browning the Green Space
Food, Water, & Land
Addressing diversity, equity, and inclusion across careers, companies, contracts, capital, and communities

SRGE
Infrastructure & Construction
Full-service accelerator to support small and underrepresented-led construction firms

Zero Homes
Infrastructure & Construction
Automated assessment, design, and procurement platform for residential building retrofits
Our Startups Have Raised Over $0B
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12,915 new jobs created by our members, and counting
Boston
7,492
Houston
5,423
Startups bring the breakthroughs. Corporate partners bring the scale, infrastructure, expertise, and capital to make them matter.
Ready to take your technology to the next level? Join the world's largest community of climatetech and energy entrepreneurs and fast-track your speed to market.


Become a Partner
Access the most concentrated pipeline of vetted climatetech companies in North America. Partner on pilots, invest, or join as a corporate sponsor.

Get Involved
We pride ourselves on being a convener of the climatetech ecosystem. Join us at an upcoming event to explore all things climate action and collaboration.

Learn About our Programs
In addition to our Boston and Houston incubators, Greentown runs programs designed to address critical challenges in the climatetech ecosystem.























