Investors Circle (IC) has long supported cleantech innovation, and recent data confirms our deep commitment to the sector. In recent years, approximately 50% of IC member investments have gone to cleantech startups. In 2024, over 62% of presenting companies at IC monthly gatherings were in cleantech.

Recognizing this momentum, we launched the IC Cleantech Circle (ICCC) in 2025 to strengthen our impact and deepen collaboration across the cleantech investment ecosystem.

What Does This Mean?

The IC Community is expanding its efforts to partner with angel investors, family offices, VCs, corporate investors, incubators, accelerators, and venture studios to identify and fund high-impact, high-return cleantech startups. Our primary focus is on companies poised for strong financial growth while driving meaningful environmental and social impact.

How Will We Achieve This?

1. Building a Collaborative Cleantech Investor Community: ICCC unites key players in early-stage cleantech investing to foster partnerships and co-investment opportunities.

2. Holding periodic Cleantech Mixers – After our May 20, 2025 Mixer we anticipate our next Mixer will be Sept. or Oct. 2025: ICCC plans on hosting regular online Cleantech Mixers, where funding partners will introduce selected founders to pitch their companies.  See the list of the May 20 Mixer presenting companies further below.

3. Ongoing Engagement & Deal Flow: ICCC will continue to host regular online and in-person events, offering investors exclusive access to top-tier cleantech startups.

Get Involved!

We invite investors, sponsors, and community partners to be part of this initiative. Membership in IC is not required to attend the an ICCC Mixer, and there is no cost to be an IC community partner or to introduce a cleantech company.

• Connect with the IC team about becoming an ICCC community partner or investor interested in collaboration with IC.  

• Attend our next ICCC Mixer, anticipated for Sept. or Oct. 2025.  Email our team at the email below to be added to the email list for the ICCC and we will notify you when registration opens. 

• Submit a startup for consideration: If you have backed or incubated a cleantech startup and would like them to be considered to present, apply via Investors Circle Dealum link for the ICCC.

• Be Our Guest: Experience the IC Community before deciding to join. Register for an upcoming event on our [events page].

• Questions? Contact us at info[at]investors-circle[dot]org.

May 20 Mixer Presenting Companies: 

INOVUES: Based in Houston, TX, INOVUES developed non-invasive glazing retrofit systems for upgrading building facades and windows without replacement.  We develop and manufacture innovative facade/window retrofits. We are an IP-driven engineering company with an asset-light manufacturing model. We sell our products to building owners and contractors. Nominated to present by John Paulos and other Central Texas Angel Network (CTAN) members (also a Cleantech Open Alumni Company). Anas Kassas, Founder & CEO – www.inovues.com

VesprSolar: Based in Norman, OK, VesprSolar disrupts inefficient commodity fasteners & mounting systems in large-scale solar projects via IP-protected, strong margined, quick-to-install clamps & optimized structural components.  These products replace commodity solutions like bolts, nuts and washers. Our products deliver >65% reduction in labor vs commodity solutions (validated by 3rd party), and significantly improve reliability of PV modules under severe wind events. Nominated to present by Tom Blum, New York Angels and Clean Energy Venture Group (CEVG) member. Robert Sewell, Co-Founder & CEO – www.vesprsolar.com

Ouros Materials: Based in NYC, Ouros Materials is materials startup developing high-performance carbon-negative composites for construction, with the mission of making housing more durable, affordable, and sustainable. Ouros is commercializing a new material that is 10x tougher than concrete, ultra-strong, fire-resistant, and 3x cheaper than competitors, all while powered with a novel manufacturing process that uses 80% less heat than industry and economically utilizes CO2.  Nominated to present by Brian Kerns, SW Angel Network / Investors Circle Member and VentureWell Ascend Energy and Mobility Mentor-In-Residence (also a VentureWell Alumni Company). Teresa Liu, Co-Founder & CEO – www.ourosmaterials.com

Accelerate Wind: Based in Birmingham, AL, Accelerate Wind is producing energy for commercial buildings with a patented roof-edge wind turbine that takes advantage of how wind accelerates over buildings and can complement solar.  Nominated to present by BRITE Energy Innovators and Tom Blum, New York Angels and CEVG member (also a Cleantech Open Alumni Company). Erika Boeing, Founder & CEO – www.acceleratewind.com

OXbyEL Technologies: Based in Phoenix, AZ, OXbyEL Technologies is commercializing the business to economically destroy pollutants including PFAS in drinking water resulting in zero liquid discharge and optimizing water reuse.  Nominated to present by Damoder Reddy, Chemical Angels Network and Tech Coast Angels member (also a Cleantech Open Alumni Company). Ed Ricci, Co-Founder & CEO – www.oxbyel.com

CarbonBridge: Based in Harlem, NY and San Jose, CA, CarbonBridge converts methane to carbon-negative green methanol using microbes - at ambient pressure and temperature.  Nominated to present by Andrew Eil, Princeton Alumni Angels member (also an ARPA-E, SOSV, and Cleantech Open Alumni Company). Manu Pillai, Co-Founder & CEO – https://www.carbonbridge.io

Green Steel Environmental: Based in Boulder, CO, Green Steel Environmental is using a clean-tech product to disrupt a $2B hazardous chemicals market in the wastewater treatment industry. They have found a way to upcycle a waste product from steel manufacturing and to sell it to wastewater treatment plants, dairy farms, and industrial wastewater treatment operators. Their customers use this product to produce clean water and renewable energy. Nominated to present by Peter Adams and other Rockies Venture Club (RVC) angel investors. Jonathan Teaford, Co-Founder & CEO – www.greensteelenvironmental.com

GreenIRR: Based in Westport, CT, GreenIRR is a carbon accounting platform built specifically for the trucking industry. They drive bottom-up supply chain transparency through partnering with mid-market and enterprise fleets, to automatically measure real time emissions and generate regulation-compliant reports. Their platform delivers efficiency analytics, benchmarking, and vehicle performance insights to improve carriers’ profitability while meeting customer sustainability demands and enhancing competitiveness in the market. Nominated to present by SoundBoard Venture Fund; Chloe Capital; Executive Forum Angels; Angel Investors Forum; and Accelerating Angels (and also a Greentown Labs and Cleantech Open Alumni Company). Celine King, Founder & CEO – www.greenirr.com

Linebird: Based in Ashland, VA, Linebird provides patented drone payload tools and equipment for off-the-shelf drones that enable utilities and their service providers to perform hands-on work on power lines, making line work safer and accelerating grid expansion. Nominated to present by Mike Brennan and the New York Angels (and also a Cleantech Open Alumni Company). Michael Beiro, Founder & CEO – www.linebird.net

NuCube Energy: Based in Pasadena, CA, but operating from Idaho Falls, ID, NuCube is developing a nuclear reactor to bring affordable power to remote areas, high temperature heat for industrial applications and in the future power for data centers. We design, sell, and operate nuclear reactors. Our design is the simplest nuclear reactor currently being developed.  Nominated to present by Kathleen Hebert and other E8 Angels members. Cristian Rabiti, Founder & CEO Cristian Rabiti, Founder & CEO – www.nucube.energy

A Short History of Investors Circle Community “Circles”

One of IC’s greatest strengths is its collaborative approach—bringing together investors who share a passion for social and environmental impact. Over the years, IC members have formed “circles” around key investment themes:

• IC’s Roots: IC itself emerged from a sustainable investing circle founded by Susan Davis.

• The Capital Circle: A group of IC investors formed a women-led investment network, which was folded into IC shortly thereafter.

• Expanding Circles: Over our over 30-year history, IC members have continued to create impact-focused investment circles to support groundbreaking startups.

Now, in 2025, IC’s Board of Directors is launching new community circles, beginning with Cleantech, with additional impact circles expected to be announced later this year.

We look forward to building this movement together!