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

Dandelion Energy
Infrastructure & Construction
Geothermal heating and cooling systems for homes

Janta Power
Energy & Power
The world’s first 3D solar tower technology

Solar Mantle
Infrastructure & Construction
Film that reflects sunlight for energy-free passive cooling of structures

Cella Mineral Storage
Manufacturing & Processing
Turning volcanic formations into reliable, low-cost CO₂ storage

Innovator Energy
Energy & Power
Developing and deploying solutions in cooling, heating, and heat transfer

HKG Energy
Energy & Power
Silicon materials that increase battery energy density

GigaDAC
Energy & Power
Direct air capture optimized for gigaton scale

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

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

WhaleSpotter
Transportation & Logistics
Thermal imaging and AI to prevent marine mammal strikes at sea

ATS Energy
Energy & Power
Converting waste heat into power without any moving parts

Dottir Labs
Food, Water, & Land
Sensor technology that provides real-time, detailed chemical analysis of water

AllSpice.io
Infrastructure & Construction
A collaboration hub for hardware teams with revision control, design reviews, and releases

Tato Labs
Manufacturing & Processing
Bioplastic products and packaging solutions made from potato starch

Cocoa Potash
Food, Water, & Land

Laminar
Manufacturing & Processing
IoT platform optimizing industrial liquid and fluid systems in supply chain, manufacturing, and data centers

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

GeoTeknica
Manufacturing & Processing

Elemental Advanced Materials
Manufacturing & Processing
Graphene and hydrogen from mixed and contaminated waste plastics and other organic materials

Sublime Systems
Infrastructure & Construction
Decarbonizing cement-making with an electrochemical process that replaces fossil-fuel-fired kilns

Dandelion Energy
Infrastructure & Construction
Geothermal heating and cooling systems for homes

Janta Power
Energy & Power
The world’s first 3D solar tower technology

Solar Mantle
Infrastructure & Construction
Film that reflects sunlight for energy-free passive cooling of structures

Cella Mineral Storage
Manufacturing & Processing
Turning volcanic formations into reliable, low-cost CO₂ storage

Innovator Energy
Energy & Power
Developing and deploying solutions in cooling, heating, and heat transfer

HKG Energy
Energy & Power
Silicon materials that increase battery energy density

GigaDAC
Energy & Power
Direct air capture optimized for gigaton scale

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

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

WhaleSpotter
Transportation & Logistics
Thermal imaging and AI to prevent marine mammal strikes at sea

ATS Energy
Energy & Power
Converting waste heat into power without any moving parts

Dottir Labs
Food, Water, & Land
Sensor technology that provides real-time, detailed chemical analysis of water

AllSpice.io
Infrastructure & Construction
A collaboration hub for hardware teams with revision control, design reviews, and releases

Tato Labs
Manufacturing & Processing
Bioplastic products and packaging solutions made from potato starch

Cocoa Potash
Food, Water, & Land

Laminar
Manufacturing & Processing
IoT platform optimizing industrial liquid and fluid systems in supply chain, manufacturing, and data centers

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

GeoTeknica
Manufacturing & Processing

Elemental Advanced Materials
Manufacturing & Processing
Graphene and hydrogen from mixed and contaminated waste plastics and other organic materials

Sublime Systems
Infrastructure & Construction
Decarbonizing cement-making with an electrochemical process that replaces fossil-fuel-fired kilns

BLU NXT
Energy & Power
Solar concentrators for high-temperature heat and energy

NOC Energy
Energy & Power
Decarbonizing industrial heat with power-to-heat and power-to-power solutions

Newfound Materials
Manufacturing & Processing
Predictive engine for materials R&D for new pathways to critical minerals

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

Phoenix Tailings
Manufacturing & Processing
Waste-free, net-zero, cost-competitive rare-earth-metal refining

RotorVault
Energy & Power
Energy-storage and load-following solutions for grid-scale and commercial applications

GS Vortex Systems
Food, Water, & Land
Hydrodynamic flow technology reducing flow resistance through pipes

Sheetak
Manufacturing & Processing
Based in Austin, Texas, Sheetak develops advanced thermoelectric, solid-state cooling, and energy harvesting technologies for high-performance electronics. With expertise in thermoelectric materials, device engineering, and U.S.-based manufacturing, Sheetak provides precision thermal management solutions for applications in photonics, telecommunications, aerospace, defense, computing, and medical systems.

Cala Systems
Energy & Power
Intelligent heat-pump water heaters

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

Wellbore Consultants
Energy & Power
Advanced subsurface stimulation systems to improve resource recovery while reducing energy intensity, water usage, and surface impact

Circular Materials
Manufacturing & Processing
Critical raw materials from industrial wastewater

SRECTrade
Energy & Power
Management and transaction platform for environmental commodities to reduce costs and increase transparency

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

Wootz
Manufacturing & Processing
Carbon nanotube supermaterials to replace or augment traditional metallic conductors

ETAK
ETAK transforms waste into clean energy. Our modular technology converts unsorted municipal and industrial waste into high-calorific gas, offering a decentralized, 24/7 alternative to fossil fuels and traditional incineration.

Solar Materials
Energy & Power
Recovered and recycled secondary solar panel materials

HarvestAi
Food, Water, & Land
Computer vision and AI to provide greenhouse operators with automated data for optimized harvest planning

Haffner Energy
Energy & Power
Producing renewable energy via waste-biomass thermolysis

Carbonext
Manufacturing & Processing
3D-graphene technology that develops integrated solutions with carbon-coated silicon anodes

BLU NXT
Energy & Power
Solar concentrators for high-temperature heat and energy

NOC Energy
Energy & Power
Decarbonizing industrial heat with power-to-heat and power-to-power solutions

Newfound Materials
Manufacturing & Processing
Predictive engine for materials R&D for new pathways to critical minerals

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

Phoenix Tailings
Manufacturing & Processing
Waste-free, net-zero, cost-competitive rare-earth-metal refining

RotorVault
Energy & Power
Energy-storage and load-following solutions for grid-scale and commercial applications

GS Vortex Systems
Food, Water, & Land
Hydrodynamic flow technology reducing flow resistance through pipes

Sheetak
Manufacturing & Processing
Based in Austin, Texas, Sheetak develops advanced thermoelectric, solid-state cooling, and energy harvesting technologies for high-performance electronics. With expertise in thermoelectric materials, device engineering, and U.S.-based manufacturing, Sheetak provides precision thermal management solutions for applications in photonics, telecommunications, aerospace, defense, computing, and medical systems.

Cala Systems
Energy & Power
Intelligent heat-pump water heaters

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

Wellbore Consultants
Energy & Power
Advanced subsurface stimulation systems to improve resource recovery while reducing energy intensity, water usage, and surface impact

Circular Materials
Manufacturing & Processing
Critical raw materials from industrial wastewater

SRECTrade
Energy & Power
Management and transaction platform for environmental commodities to reduce costs and increase transparency

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

Wootz
Manufacturing & Processing
Carbon nanotube supermaterials to replace or augment traditional metallic conductors

ETAK
ETAK transforms waste into clean energy. Our modular technology converts unsorted municipal and industrial waste into high-calorific gas, offering a decentralized, 24/7 alternative to fossil fuels and traditional incineration.

Solar Materials
Energy & Power
Recovered and recycled secondary solar panel materials

HarvestAi
Food, Water, & Land
Computer vision and AI to provide greenhouse operators with automated data for optimized harvest planning

Haffner Energy
Energy & Power
Producing renewable energy via waste-biomass thermolysis

Carbonext
Manufacturing & Processing
3D-graphene technology that develops integrated solutions with carbon-coated silicon anodes
Our Startups Have Raised Over $0B
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Startups Operate
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.























