Issue link: https://nebusinessmedia.uberflip.com/i/1537483
26 Worcester Business Journal | Book of Lists 2025 | wbjournal.com F O C U S P R O F E S S I O N A L S E R V I C E S Largest clean energy companies Ranked by number of local employees Company Local employees/ companywide Type of business Products and services Top executive(s)/ year founded 1 Babcock Power Services, Babcock Power Environmental 26 Forest St., Suite 300, Marlborough 01752 508-852-7100 • babcockpower.com 500 (1) N/A Solar, biomass and waste-to- energy Technology, equipment and engineering services Wade Shephard president & CEO, Babcock Power Services & Babcock Power Environmental Michael Leclair president & CEO, Babcock Power Inc. 1913 1 Milton CAT (2) 100 Quarry Drive, Milford 01757 508-634-3400 • miltoncat.com 500 (3) 1,000 Caterpillar machines for power generation and energy storage Includes MC2 Renewable Energy Services, a full-service renewable energy division within Milton CAT Chris Milton president & CEO 1960 3 Aspen Aerogels Inc. 30 Forbes Road, Northborough 01532 508-691-1111 • aerogel.com 159 (4) 554 (4) Development and manufacturing of aerogels for clean energy and electrification solutions PyroThin products for electric vehicles and carbon aerogel initiative to increase performance of lithium-ion battery cells Don Young president & CEO 2001 4 Ameresco Inc. 111 Speen St., Suite 401, Framingham 01701 866-263-7372 • ameresco.com 157 (4) 1,498 (4) Cleantech integrator and renewable energy asset developer, owner & operator Energy efficiency, renewable generation & energy supply, infrastructure upgrades, energy software & services George Sakellaris president & CEO 2000 5 Ostrow Electric Co. 9 Mason St., Worcester 01609 508-754-2641 • ostrowelectric.com 121 (4) 202 (4) Electrical infrastructure from bidding to design-build and engineering Photovoltaic systems for rooftop & large-scale ground mount, wind turbine generators Matthew Ostrow president 1939 6 Commonwealth Fusion Systems (CFS) 117 Hospital Road, Devens 01434 781-606-1233 • cfs.energy 114 (4) 650 (4) Fusion energy systems Alcator C-Mod compact, high- magnetic field tokamak, high- temperature superconducting (HTS) magnets for fusion energy generation Bob Mumgaard CEO 2018 7 Solect Energy 89 Hayden Rowe St., Hopkinton 01748 508-598-3511 • solect.com 110 N/A Commercial solar developer and operator with 800+ installations, 700+ current operations and maintenance customers, and 160+ MW of solar energy installed. Design, installation, optimization and maintenance of commercial solar & storage solutions Kenneth Driscoll CEO 2009 8 AMSC (5) 114 E. Main St., Ayer 01432 978-842-3000 • amsc.com 100 (6) 569 Technologies for grid and wind segments Wind turbine system designs licensed under Windtec Solutions with products & services for wind turbine manufacturers Daniel McGahn president & CEO 1987 9 Ascend Elements (7) 133 Flanders Road, Westborough 01581 508-936-7701 • ascendelements.com 95 300 Battery materials manufacturing & recycling Custom lithium-ion battery materials, cathode precursor (pCAM) and lithium carbonate, from recycled batteries & manufacturing scrap; lithium-ion battery recycling services to manufacturers & electric vehicle OEM's Linh Austin president & CEO 2015 10 Donahue & Sons 123 Cut Off Road, Barre 01005 508-380-2082 • donahuesons.com 61 61 Operation and maintenance of solar installations Vegetation management, solar panel washing, solar panel snow removal, critical infrastructure repair Tom Donahue president 2010 10 Endless Energy New England Inc. 261 Cedar Hill St., Suite 100, Marlborough 01752 508-357-2354 • goendlessenergy.com 61 78 Certified Mass Save contractor, HVAC, insulation, plumbing, electrical HVAC systems installation & service, home energy assessments, weatherization & insulation, load management, e- vehicle charging stations, service upgrades Matt Kidd president Amanda Perkins chief operating officer 1980 12 Ambri (8) 53 Brigham St., Suite 8, Marlborough 01752 617-714-5723 • ambri.com 60 65 Manufacturer Grid-scale battery storage for renewable energy David Bradwell CEO 2010 13 Modern Energy 24 Rockdale St., Worcester 01606 508-449-0449 • modernenergynow.com 45 42 Renewable energy & electrification Design & installation of commercial variable refrigerant flow (VRF) heat pumps, residential mini split heat pumps; insulation, solar PV & LED lighting upgrades John Pitcavage Jeff Vlk co-founders 2017 14 ThinkLite Air LLC 117 West Central St., Suite 201, Natick 01760 617-500-6689 • thinklite.com 34 N/A Indoor air monitoring and purification solutions Indoor air quality monitor with automated alerts, LED light panel and medical-grade air purifier, large space portable medical- grade air purifier Dinesh Wadhwani founder & CEO 2009 15 New England Clean Energy Inc. 577 Main St., Suite 430, Hudson 01749 978-567-6527 • newenglandcleanenergy.com 32 N/A Solar panel and battery installation & service Installation & service of solar panels and batteries for small to midsized commercial & residential systems Douglas McCartney CEO Mark Durrenberger (9) founder & president 2006 Source: Each company via survey as of Q2 2025. Notes: Unable to confirm local employee count by press time for Westborough's LG Energy Solution Vertech Inc., with 150 local employees reported on WBJ's 2023 survey, or Electric Hydrogen, with 300 companywide employees and facilities in Devens and Natick. N/A=not available. (1) Local employee count falls within a range of 500 to 999, according to Mass. Executive Office of Labor and Workforce Development. (2) Includes MC2 Renewable Energy Services, a full- service renewable energy division of Milton CAT (3) Local employee count falls within a range of 500 to 999, according to Mass. Executive Office of Labor and Workforce Development. (4) Employee counts from WBJ's 2024 survey (5) Formerly known as American Superconductor Corp. (6) Local employee count falls within a range of 100 to 249, according to Mass. Executive Office of Labor and Workforce Development. (7) Formerly Battery Resourcers (8) Emerged from Chapter 11 bankruptcy in July 2024; data is from WBJ's survey, as of March 21, 2024. (9) Additional leadership includes Evan Vana, chief operating officer -Compiled by: Stephanie R. Meagher, research@nebusinessmedia.com Framingham-based energy resilience firm Ameresco has purchased ASA Controls, a contractor and system integrator based in Cincinnati, Ohio, in an effort to boost its smart buildings and control offerings. ASA Controls was founded in 2003 and has developed a reputation for optimizing function- ality and operational efficiency of buildings, according to a March 3 press release issued by Ameresco. "We are thrilled to welcome ASA Controls to the Ameresco family," Lou Maltezos, president of Central & Western USA, Canada Regions at Ameresco, said in the press release "The combined expertise and resources of our teams will enable us to tackle larger, more complex projects and drive significant value for our customers." Financial terms of the trans- action were not disclosed, but Ameresco does not expect the purchase will have a material im- pact on its 2025 financial results. "We are excited about the opportunities this acquisition brings," Mike Agnew, managing founder of ASA Controls, said in the press release. "Joining forces with Ameresco allows us to leverage their extensive resources and expertise, providing even greater value to our customers and supporting the growth and development of our team." The global smart building market was valued at $108 billion in 2023, according to Califor- nia-based research firm Grand View Research. Ameresco announced in December it will be building a $8-million microgrid project in the Canadian province of New Brunswick, one of several large government contracts it has obtained. The firm has received more than $494 million in government contract award pay- ments in the last year, according to Nasdaq.com. – Story by Eric Casey Ameresco purchases Ohio- based smart building firm