David Brewster

Climate tech entrepreneur and investor. Co-founder @EnerNOC.

📍 Greater Boston, United States🔄 Updated September 2026💼 11 investments📅 16 years investing🗓 Last invested Dec 2025
VC🌍 United StatesInvested this year
11
Total investments
4
Early stage
2
Mid stage
2
Late stage
16y
Years active

Portfolio

11 investments · sorted by recency
All investments
Early stage
Mid stage
Late stage
Board Member
Dec 2025
SYSO Technologies envisions a power grid free from the use of fossil fuels. In order to achieve this vision, SYSO is actively working with asset owners to transform passive renewable generators into active renewable generation via SYSOs cloud-based Energy Management Platform.
Board Member
Aug 2023
PearlX answers the societal call for an energy transition by making the benefits of clean power accessible to renting households regardless of credit score or income level. PearlX finances, develops, installs, and manages clean energy amenities tailored to a community’s needs.
mid stageReal Estate
Board Member
Jan 2020
Vicinity Energy is a clean energy company that owns and operates the largest portfolio of district energy systems nationwide. Vicinity produces and distributes reliable clean steam, hot water, and chilled water to over 230 million square feet of building space nationwide. Vicinity is committed to achieving net zero carbon across its portfolio by 2050. Vicinity continuously invests in its infrastructure and the latest technologies to accelerate the transition and rapidly decarbonize commercial and institutional buildings in city centers.
early stageUtilities
Investor / Board Member
Jan 2019
Support the expanding energy economy by equipping our utility partners with digital infrastructure solutions needed to integrate new energy sources, mitigate extreme weather events, and meet the challenges of a new energy paradigm. Follow us on Twitter: @LineVisionCo LineVision provides electric utilities with the real-time monitoring and analytics needed to accelerate the net-zero grid. LineVision’s patented non-contact sensors collect critical information to unlock additional capacity on existing lines, provide insight into conductor health, and detect anomalies and risks. LineVision’s platform is rapidly deployed at scale without the need for scheduled outages, live line work, or specialized installation equipment. LineVision is helping our utility partners around the world lead the energy transition by increasing the capacity, resilience, and safety of the grid.
Board Member
Jan 2019
Support the expanding energy economy by equipping our utility partners with digital infrastructure solutions needed to integrate new energy sources, mitigate extreme weather events, and meet the challenges of a new energy paradigm. Follow us on Twitter: @LineVisionCo LineVision provides electric utilities with the real-time monitoring and analytics needed to accelerate the net-zero grid. LineVision’s patented non-contact sensors collect critical information to unlock additional capacity on existing lines, provide insight into conductor health, and detect anomalies and risks. LineVision’s platform is rapidly deployed at scale without the need for scheduled outages, live line work, or specialized installation equipment. LineVision is helping our utility partners around the world lead the energy transition by increasing the capacity, resilience, and safety of the grid.
Board Member
Aug 2018
At Mantis Innovation, our experts provide data-driven, consultative services designed to optimize your facility, sustainability, and energy management strategies, while ultimately making your lives easier with trusted, unbiased solutions designed to generate value. We’ll guide you in making the right decision at the right time, providing ongoing support, custom solutions, and turnkey energy and facilities management. We’re focused on real risk management, real cost savings, and real carbon reductions. Our team provides managed facility services and turnkey program management with technology-enabled solutions that target the entire building footprint. We’re looking at the entire facility, inside and out, and can impact 70% of what a building operator allocates critical budget dollars toward including: - Strategic electricity and natural gas procurement, renewable energy, and demand response - Climate impact reduction and reporting, net zero strategies, sustainability planning - Roofing, solar, HVAC assessment management, pavement, building envelope, data center optimization, EV charging - Lighting/LED retrofits, HVAC/mechanical, and building automation systems improvements and implementation Our turnkey solutions maximize results at every touchpoint of facility performance. Our technology platforms make those touchpoints accurate and visceral, backed by data from billions of feet of facility space. We offer all of this with a white glove service, meaning our clients receive an unparalleled level of professionalism and care. Mantis is headquartered in Houston, Texas, with office locations across the United States from Massachusetts to Washington. Discover more about Mantis at www.mantisinnovation.com
Board Member
Jan 2017
Desalitech is revolutionizing the way the world treats water, delivering our clients more of the water they need with less of the headaches they don't. Our line of industrial ReFlex™ Reverse Osmosis products features our patented Closed-Circuit Reverse Osmosis (CCRO™) process that promises high performing, high recovery systems that require less over sight and less operating costs. Desalitech is making waves in the industry, winning a Global Water Intelligence “Breakthrough Technology” award in 2016 and several Global 100 CleanTech awards. Last year, Desalitech was awarded the best place to work in the water Industry due to the reviews of our employees who rave about our great culture, benefits like unlimited PTO and our forward thinking leadership team. We are always interested in talking to talented people looking to join our growing team. More details about Desalitech, the CCRO process and our career opportunities can be found at www.desalitech.com or by contacting us at info@desalitech.com.
Board Member
Jan 2017
Desalitech is revolutionizing the way the world treats water, delivering our clients more of the water they need with less of the headaches they don't. Our line of industrial ReFlex™ Reverse Osmosis products features our patented Closed-Circuit Reverse Osmosis (CCRO™) process that promises high performing, high recovery systems that require less over sight and less operating costs. Desalitech is making waves in the industry, winning a Global Water Intelligence “Breakthrough Technology” award in 2016 and several Global 100 CleanTech awards. Last year, Desalitech was awarded the best place to work in the water Industry due to the reviews of our employees who rave about our great culture, benefits like unlimited PTO and our forward thinking leadership team. We are always interested in talking to talented people looking to join our growing team. More details about Desalitech, the CCRO process, and our career opportunities can be found at www.desalitech.com or by contacting us at info@desalitech.com.
Investor
Sep 2015
6 River Systems (6RS) is an industry-leading solutions provider working to make fulfillment faster with innovative products that generate immediate and lasting value for our customers. Through an award-winning combination of collaborative robots, artificial intelligence and operational expertise, 6RS makes your entire fulfillment workflow more efficient. Our flexible, easy-to-deploy solution creates a work environment that makes it easier to attract, train and retain associates, while powerful software delivers actionable insights that enable your business to quickly adapt or scale to meet changes in demand. Founded in Waltham, Mass. in 2015 and acquired in 2019, 6 River Systems is part of global commerce company Shopify Inc. Founders Jerome Dubois and Rylan Hamilton were previously executives at Kiva Systems (now Amazon Robotics). The 6 River Systems solution is operating in facilities in the U.S., Canada and Europe, fulfilling millions of units each week for companies including Lockheed Martin, CSAT Solutions, ACT Fulfillment, DHL, XPO Logistics, and Office Depot. To learn about 6 River Systems and its wall-to-wall fulfillment solution, please visit 6river.com.
Seed Investor
Sep 2015
6 River Systems (6RS) is an industry-leading solutions provider working to make fulfillment faster with innovative products that generate immediate and lasting value for our customers. Through an award-winning combination of collaborative robots, artificial intelligence and operational expertise, 6RS makes your entire fulfillment workflow more efficient. Our flexible, easy-to-deploy solution creates a work environment that makes it easier to attract, train and retain associates, while powerful software delivers actionable insights that enable your business to quickly adapt or scale to meet changes in demand. Founded in Waltham, Mass. in 2015 and acquired in 2019, 6 River Systems is part of global commerce company Shopify Inc. Founders Jerome Dubois and Rylan Hamilton were previously executives at Kiva Systems (now Amazon Robotics). The 6 River Systems solution is operating in facilities in the U.S., Canada and Europe, fulfilling millions of units each week for companies including Lockheed Martin, CSAT Solutions, ACT Fulfillment, DHL, XPO Logistics, and Office Depot. To learn about 6 River Systems and its wall-to-wall fulfillment solution, please visit 6river.com.
Board Member
Dec 2010
EnergyHub is a dynamic software technology company based in New York, NY. EnergyHub's platform lets consumers turn their smart thermostats, water heaters, and other products into virtual power plants that keep the grid stable and enable higher penetration of solar and wind power. We work on technology that already provides energy and cost savings to more than a million people through partnerships with the most exciting companies in the 'internet of things.'​ EnergyHub is an independent subsidiary of Alarm.com, the leading technology provider of connected home solutions.
Experience · 15 entries
All (15)
Investments (11)
Founder (2)
Board (9)
2025
Board Member
Dec 2025
SYSO Technologies envisions a power grid free from the use of fossil fuels. In order to achieve this vision, SYSO is actively working with asset owners to transform passive renewable generators into active renewable generation via SYSOs cloud-based Energy Management Platform.
2023
Board Member
Aug 2023
PearlX answers the societal call for an energy transition by making the benefits of clean power accessible to renting households regardless of credit score or income level. PearlX finances, develops, installs, and manages clean energy amenities tailored to a community’s needs.
mid stageReal Estate
2021
Advisor
Jun 2021
Antin Infrastructure Partners is a leading private equity firm focused on infrastructure. With over €33bn in Assets under Management, Antin targets majority stakes in the energy and environment, digital, transport and social infrastructure sectors. Based in Paris, London, New York, Singapore, Seoul and Luxembourg, Antin employs over 240 professionals dedicated to growing, improving and transforming infrastructure businesses while delivering long-term value to investors and portfolio companies. Majority owned by its partners, Antin is listed on compartment A of the regulated market of Euronext Paris (Ticker: ANTIN – ISIN: FR0014005AL0)
2020
Board Member
Jan 2020
Vicinity Energy is a clean energy company that owns and operates the largest portfolio of district energy systems nationwide. Vicinity produces and distributes reliable clean steam, hot water, and chilled water to over 230 million square feet of building space nationwide. Vicinity is committed to achieving net zero carbon across its portfolio by 2050. Vicinity continuously invests in its infrastructure and the latest technologies to accelerate the transition and rapidly decarbonize commercial and institutional buildings in city centers.
early stageUtilities
2019
Investor / Board Member
Jan 2019
Support the expanding energy economy by equipping our utility partners with digital infrastructure solutions needed to integrate new energy sources, mitigate extreme weather events, and meet the challenges of a new energy paradigm. Follow us on Twitter: @LineVisionCo LineVision provides electric utilities with the real-time monitoring and analytics needed to accelerate the net-zero grid. LineVision’s patented non-contact sensors collect critical information to unlock additional capacity on existing lines, provide insight into conductor health, and detect anomalies and risks. LineVision’s platform is rapidly deployed at scale without the need for scheduled outages, live line work, or specialized installation equipment. LineVision is helping our utility partners around the world lead the energy transition by increasing the capacity, resilience, and safety of the grid.
Show all 15 entries ↓
Investment activity
2010–2025 · 11 investments
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