Best Environment Companies in Connecticut, United States
The 87 best Environment companies in Connecticut, United States in 2026, ranked by funding and momentum. Funding, investors, founders, valuation, tech stack and live signals. Top: Greenskies.
Our analysis of 90 Environment companies
$38.2b in tracked funding; 89% of the stack-profiled cohort runs cloud-native; funding activity peaked in 2025.
Ranked: Best Environment companies in Connecticut
| # | Company | Disclosed funding | Last round | Stage | Founder | Founded | Tech stack | Patents & IP focus | Recent signals |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Greenskies Vertically-integrated solar energy solutions provider for commercial, public sector, and utility clients | $247M | 77 mo ago | Acquired | — | 2008 | — | — | 2 expansions |
| 2 | Infiltrator Wastewater treatment systems manufacturer | $186M | 132 mo ago | Acquired | Roy Moore CEO & President | 1987 | Apple iCloud MailZohoMicrosoft ASP.NET+14 | — | 4 job openings |
| 3 | Oakleaf Waste Management Provider of waste recovery and recycling services | $30M | 278 mo ago | Acquired | Jim Barnes CEO | 1995 | — | — | — |
| 4 | Oak Ridge Waste & Recycling Provider of trash collection, container rental, and recycling services | $28M | 150 mo ago | Acquired | — | 2007 | WordPressMySQLMariaDB+28 | — | — |
| 5 | STR Solar Solar panel encapsulation leader, providing environmentally-responsible solutions through research and… | $22M | 142 mo ago | Public | — | 1944 | — | — | — |
| 6 | Protein Evolution Provider of plastic waste services | $20M | 43 mo ago | Series B | Connor Lynn Co-Founder & CBO | 2021 | Radix UITailwind CSSshadcn/ui+6 | 20 patents Enzymatic degradation and recycling of crystallizable polymer plastics and micro‑particle separation | — |
| 7 | BullBag Provider of solutions for waste collection | $9M | 92 mo ago | Series B | — | 2006 | Apple iCloud MailMicrosoft 365Java+12 | — | — |
| 8 | Apollo Solar Solar power solutions for remote telecom and off-grid applications | $4M | 213 mo ago | Series A | John Pfeifer Founder & CEO | 2003 | — | — | — |
| 9 | Roundtrip EV Provider of end-to-end solutions for transitioning to electric truck fleets | $850K | 25 mo ago | Series A | James Sherman Co-Founder | 2020 | — | 15 patents Secure low-power real-time asset tracking and geofencing for electric vehicle fleets | — |
| 10 | ainwater Provider of wastewater management services | $537K | 21 mo ago | Seed | Camilo Huneeus CEO | 2020 | WordPressMySQLPHP+16 | — | — |
| 11 | Green Buildings Provider of consulting services for green buildings projects | $450K | 162 mo ago | Seed | Cyrille Jourdan Co-Founder | 2008 | — | — | — |
| 12 | Biomass Controls Provider of waste & water management services | $100K | 83 mo ago | Funding Raised | Jeff Hallowell Founder | 2015 | — | — | — |
Top 12 Environment companies in Connecticut
#1
Seed · New Haven, Connecticut · founded 2020$537Kraised▾
Provider of wastewater management services
- Aug 2024Seed$537K
- Apr 2024Grant (prize money)—
#2
Series A · Stamford, Connecticut · founded 2020 · 8 employees$850Kraised▾
Provider of end-to-end solutions for transitioning to electric truck fleets. The company offers services including site evaluation, fleet optimization, and long-range planning for transitioning to electric trucks. It prepares electrical drawings, obtains permits, and builds charging infrastructure. The company also provides ongoing monitoring, maintenance, and software for fleet management and performance optimization.
- May 2024Series A$975K
- Oct 2022Seed$850K
#3
Acquired · Middletown, Connecticut · founded 2008 · 83 employees$247Mraised▾
Vertically-integrated solar energy solutions provider for commercial, public sector, and utility clients. The company offers comprehensive decarbonization solutions, including onsite and offsite solar, battery storage, microgrids, and combined cooling, heating, and power. They originate, develop, construct, and operate renewable energy facilities. The company provides project financing, operations and maintenance, project acquisition, and co-development services. They cater to landowners, building owners, commercial and industrial entities, municipalities and schools, nonprofits, universities, and hospitals. Their offerings include solar plus new roof options, parking lot solar installations, utility-scale projects, and community solar programs. They focus on environmental, social, and governance goals, providing clean energy solutions and promoting sustainability.
- Jan 2020PE—
- Aug 2015Conventional Debt$165M
- Jul 2014Conventional Debt$82M
#4
Series B · New Haven, Connecticut · founded 2021 · 34 employees$20Mraised▾
Provider of plastic waste services
- Nov 2022Series B$20M
#5
Acquired · Old Saybrook, Connecticut · founded 1987 · 398 employees$186Mraised▾
Wastewater treatment systems manufacturer
- May 2015Series D$186M
#6
Acquired · Danbury, Connecticut · founded 2007 · 400 employees$28.5Mraised▾
Provider of waste removal and recycling services intended for homes and businesses. The company offers regional solid waste collection, recycling and disposal services to residential and commercial customers including office buildings, shopping malls, private homes, restaurants and conference centres as well as local and county municipalities, apartment buildings, hotels, motels and industrial centers in the Northeastern United States.
- Nov 2013PE$28.5M
- 2013Seed—
#7
Acquired · Windsor, Connecticut · founded 1995 · 650 employees$30Mraised▾
Provider of logistics services related to waste and recycling solutions. The company has a nationwide network of 2,500 preferred haulers and more than 85,000 locations served throughout North America.
- Apr 2003PE$30M
#8
Public · Enfield, Connecticut · founded 1944 · 63 employees$21.7Mraised▾
Solar panel encapsulation leader, providing environmentally-responsible solutions through research and innovation. The company is dedicated to advancing renewable energy through scientific breakthroughs in solar encapsulation. With a history rooted in the development of EVA-based solar encapsulants, the company demonstrates a long-standing commitment to the solar industry. The company focuses on continual research, development, and innovation to provide its customers with environmentally responsible solutions. This makes them a key player in the renewable energy sector, contributing to a more sustainable future through advanced materials and technologies. The company's work directly supports the growth and efficiency of solar energy adoption worldwide, making it a business with a significant positive social impact.
- Aug 2014PE$21.7M
- Sep 2005Conventional Debt—
#9
Series B · Killingworth, Connecticut · founded 2006 · 23 employees$9.2Mraised▾
Provider of solutions for waste collection
- Oct 2018Series B$5.9M
- Aug 2017Series A$3.3M
#10
Series A · Bethel, Connecticut · founded 2003 · 21 employees$4.5Mraised▾
Solar power solutions for remote telecom and off-grid applications. The company provides power generation equipment in pure solar and solar/DG hybrid configurations, enabling telecommunications companies to deliver services in remote or challenging locations. They offer off-grid systems that increase reliability and reduce power costs, featuring charge controllers and true sine wave inverters suitable for diverse environments. Their pre-wired panels and cabinets are factory-assembled and tested, ensuring easy installation and minimal downtime through remote monitoring. The company focuses on increasing performance and enhancing the reliability of photovoltaic systems, reducing the cost of residential, commercial, and remote telecom PV installations. They offer inverters, charge controllers, and monitoring modules for PV power management systems. The company's products are designed for fast installation, feature built-in energy-performance meters, incorporate internet-based remote data-monitoring, and reflect robust thermal design for optimal solar energy harvest.
- Sep 2008Series A$4.5M
#11
Seed · Ridgefield, Connecticut · founded 2008$450Kraised▾
Developer of an online education website designed to specialize in professional project experience and continuing education. The company's website provides education, training, and information to green building professionals about LEED certification, green products and topics related to commercial green buildings, enabling the professionals to learn about environment-friendly energy services.
- Nov 2012Seed$150K
- Jul 2011Seed$300K
#12
Funding Raised · Putnam, Connecticut · founded 2015 · 5 employees$100Kraised▾
Developer of a renewable energy technology intended to process and valorize biogenic waste. The company's refinery produces carbon-rich biochar from inputs including manure, textiles, food, and biosolids to deliver improvements in health, the environment, and quality of life while promoting gender equality, enabling clients to recover nutrients, reduce GHG and sequester carbon.
- Jul 2019Grant (prize money)$100K
Funding & investor landscape
Notable founders
Market landscape — 10 sub-themes by coverage
Share of Environment coverage by sub-theme.
Regulatory-risk over time rising
Funding & growth over time
funding rising · growth rising
How research on Environmental Monitoring is moving in the United States
A read on the academic research around Environmental Monitoring — which themes are gaining ground, the institutions and researchers driving them, and how the tone is shifting. Based on 3,039 United States-affiliated papers.
- United States Geological Survey157
- Cary Institute of Ecosystem Studies112
- Environmental Protection Agency84
- National Research Council79
- National Park Service76
- Software deployment2→31
- Pollution3→27
- Air quality index1→25
- Water quality10→34
- Air pollution3→25
- Air quality index14→60
- Air pollution8→51
- Pollutant4→32
- Sampling (signal processing)14→42
- Water quality23→48
- Human health1→32
- Pollution4→33
- Air quality index6→31
- Pollutant6→28
- Biodiversity1→22
Where environmental monitoring is researched across United States
Location clusters by institution affiliation — each city's volume, stance tone, and a quick read on its hot topic, what's advancing, the opening opportunity, and the main concern.
Who's filing environmental monitoring patents in the United States
United States environmental monitoring patent filing is accelerating — 450 filings from 343 assignees (2016–2025), led by LEEO, Valencell, United Parcel Service; annual filings 47→49.
- LEEO41
- Valencell25
- United Parcel Service21
- Honeywell INT20
- Apple18
- Venturedyne18
- Pillar TECH17
- IND Scient16
Common questions
Riya reads income statements for fun. She covers the real money in a sector — revenue, growth, who actually earns — and never met a vague claim she didn't want a number for.