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
QuantAQ
Infrastructure & Construction
Air quality-monitoring networks that combine IoT hardware, machine learning, and user-friendly software design
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 […]
Rafi Properties
Infrastructure & Construction
change:WATER Labs
Food, Water, & Land
Low-cost, compact, waterless toilet for non-sewered households and communities
FAST Metals
Manufacturing & Processing
Hydrometallurgical-recovery process for extracting rare-earth elements from industrial tailings
Latitude Media
News, podcasts, market intelligence, and events for the climatetech industry
New Mantle Technologies
Energy & Power
Subsurface characterization with physics and AI
Janta Power
Energy & Power
The world’s first 3D solar tower technology
Carbion
Manufacturing & Processing
Affordable and clean biomass transformation to graphite for batteries
Boot Box Labs
Energy & Power
Compact, refrigerant-free thermoelectric heat pump for quiet, efficient, climate-neutral HVAC
Alma Energy
Energy & Power
Geothermal exploration to deliver scaled renewable energy production at economic levels
String Data Motion
Infrastructure & Construction
Agentic AI for energy companies. Agents in motion. Outcomes delivered.
Hera Materials
Manufacturing & Processing
Regenerative plastics made from diverse, local biomass, powered by robotics and AI
GS Vortex Systems
Food, Water, & Land
Hydrodynamic flow technology reducing flow resistance through pipes
Electric Hydrogen
Energy & Power
Manufactureing the world’s most powerful electrolyzers to produce the lowest cost clean hydrogen
Swiss Vault
Manufacturing & Processing
Revolutionizing Data Infrastructure for the AI Era
TransOceans Clean Energy Risk, LLC
Energy & Power
Risk management solutions for global clean tech risk portfolios
RIVSAL HOLDINGS INC.
Energy & Power
Power plants that run on water and deliver electricity to avoid grid vulnerability and energy price volatility
EnergyGigs
Food, Water, & Land
Talent and freelance platform for the energy industry
Provocative
Manufacturing & Processing
Replacing data centers’ cooling systems with carbon capture
QuantAQ
Infrastructure & Construction
Air quality-monitoring networks that combine IoT hardware, machine learning, and user-friendly software design
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 […]
Rafi Properties
Infrastructure & Construction
change:WATER Labs
Food, Water, & Land
Low-cost, compact, waterless toilet for non-sewered households and communities
FAST Metals
Manufacturing & Processing
Hydrometallurgical-recovery process for extracting rare-earth elements from industrial tailings
Latitude Media
News, podcasts, market intelligence, and events for the climatetech industry
New Mantle Technologies
Energy & Power
Subsurface characterization with physics and AI
Janta Power
Energy & Power
The world’s first 3D solar tower technology
Carbion
Manufacturing & Processing
Affordable and clean biomass transformation to graphite for batteries
Boot Box Labs
Energy & Power
Compact, refrigerant-free thermoelectric heat pump for quiet, efficient, climate-neutral HVAC
Alma Energy
Energy & Power
Geothermal exploration to deliver scaled renewable energy production at economic levels
String Data Motion
Infrastructure & Construction
Agentic AI for energy companies. Agents in motion. Outcomes delivered.
Hera Materials
Manufacturing & Processing
Regenerative plastics made from diverse, local biomass, powered by robotics and AI
GS Vortex Systems
Food, Water, & Land
Hydrodynamic flow technology reducing flow resistance through pipes
Electric Hydrogen
Energy & Power
Manufactureing the world’s most powerful electrolyzers to produce the lowest cost clean hydrogen
Swiss Vault
Manufacturing & Processing
Revolutionizing Data Infrastructure for the AI Era
TransOceans Clean Energy Risk, LLC
Energy & Power
Risk management solutions for global clean tech risk portfolios
RIVSAL HOLDINGS INC.
Energy & Power
Power plants that run on water and deliver electricity to avoid grid vulnerability and energy price volatility
EnergyGigs
Food, Water, & Land
Talent and freelance platform for the energy industry
Provocative
Manufacturing & Processing
Replacing data centers’ cooling systems with carbon capture
Boxes
Manufacturing & Processing
Smart, affordable, and sustainable retail combining the physical and digital worlds
Elemental Advanced Materials
Manufacturing & Processing
Graphene and hydrogen from mixed and contaminated waste plastics and other organic materials
Packwise
Manufacturing & Processing
IIoT sensors combined with a software and analytics platform to optimize industrial supply chains
Haffner Energy
Energy & Power
Producing renewable energy via waste-biomass thermolysis
Ensovi
Manufacturing & Processing
Cofactor recycling platform for sustainable drug manufacturing
Optigon
Energy & Power
Rapid, contactless characterization for assessing performance during photovoltaic solar cell fabrication
Verde Technologies
Energy & Power
Lightweight, flexible perovskite solar panels for mass industrial and commercial adoption
Dugu Systems
Energy & Power
Zero-carbon power with an emissions-free gas turbine
LiftOFF Technology
Energy & Power
Batteries with breakthrough energy density and safety
QEA Tech
Energy & Power
Precise, data-driven building-envelope audits using patented AI software, drones, and thermography
ATS Energy
Energy & Power
Converting waste heat into power without any moving parts
Timbergrove
Energy & Power
Building AI + IoT solutions that connect and optimize assets, boosting visibility, safety, and efficiency
Phoenix Tailings
Manufacturing & Processing
Waste-free, net-zero, cost-competitive rare-earth-metal refining
FlowCellutions
Energy & Power
Preventing power outages and improving cost savings for critical battery systems
Teal Bio
Manufacturing & Processing
Reusable N95 respirator system for healthcare workers to reduce landfill waste
AeroShield Materials
Infrastructure & Construction
Insulating, porous aerogels for energy-efficient windows
Lydian
Manufacturing & Processing
Fully electrified reactors for high-efficiency conversion of non-fossil feedstocks into pure syngas
Adept Materials
Infrastructure & Construction
Material innovations that improve moisture regulation, comfort, and energy efficiency
Florrent
Food, Water, & Land
High-energy-density supercapacitors for energy storage, made from domestic biomass waste
Anning Corporation
Energy & Power
Targeting iron-rich rocks to produce hydrogen
Boxes
Manufacturing & Processing
Smart, affordable, and sustainable retail combining the physical and digital worlds
Elemental Advanced Materials
Manufacturing & Processing
Graphene and hydrogen from mixed and contaminated waste plastics and other organic materials
Packwise
Manufacturing & Processing
IIoT sensors combined with a software and analytics platform to optimize industrial supply chains
Haffner Energy
Energy & Power
Producing renewable energy via waste-biomass thermolysis
Ensovi
Manufacturing & Processing
Cofactor recycling platform for sustainable drug manufacturing
Optigon
Energy & Power
Rapid, contactless characterization for assessing performance during photovoltaic solar cell fabrication
Verde Technologies
Energy & Power
Lightweight, flexible perovskite solar panels for mass industrial and commercial adoption
Dugu Systems
Energy & Power
Zero-carbon power with an emissions-free gas turbine
LiftOFF Technology
Energy & Power
Batteries with breakthrough energy density and safety
QEA Tech
Energy & Power
Precise, data-driven building-envelope audits using patented AI software, drones, and thermography
ATS Energy
Energy & Power
Converting waste heat into power without any moving parts
Timbergrove
Energy & Power
Building AI + IoT solutions that connect and optimize assets, boosting visibility, safety, and efficiency
Phoenix Tailings
Manufacturing & Processing
Waste-free, net-zero, cost-competitive rare-earth-metal refining
FlowCellutions
Energy & Power
Preventing power outages and improving cost savings for critical battery systems
Teal Bio
Manufacturing & Processing
Reusable N95 respirator system for healthcare workers to reduce landfill waste
AeroShield Materials
Infrastructure & Construction
Insulating, porous aerogels for energy-efficient windows
Lydian
Manufacturing & Processing
Fully electrified reactors for high-efficiency conversion of non-fossil feedstocks into pure syngas
Adept Materials
Infrastructure & Construction
Material innovations that improve moisture regulation, comfort, and energy efficiency
Florrent
Food, Water, & Land
High-energy-density supercapacitors for energy storage, made from domestic biomass waste
Anning Corporation
Energy & Power
Targeting iron-rich rocks to produce hydrogen
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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.