Company lists · Data refreshed September 2026
Top 25 Green energy consulting firms based in the United States
RevenueBase identified 4,315 green energy consulting firms headquartered in the United States as of September 2026 and tracks 52,375 professional contacts across them, including 22,256 with verified work emails and 21,356 with mobile numbers. Houston is the largest hub.
This list covers green energy consulting firms headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 3, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.
The 25 largest green energy consulting firms based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 1,631 contacts → | ||||
Indirect evidence “At Westwood, our purpose is to create a better world for people through our work.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 2 | 1,618 contacts → | ||||
Partial evidence “Founded on a commitment to sound science and creative solutions, SWCA is a leader in environmental and management consulting services.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 3 | 1,475 contacts → | ||||
Partial evidence “Ameresco, Inc.(NYSE:AMRC) is a leading energy infrastructure solutions provider dedicated to helping customers reduce costs, enhance resilience, and decarbonize to net zero in the…” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 4 | 838 contacts → | ||||
Partial evidence “Willdan (NASDAQ: WLDN) provides professional consulting and technical services to utilities, public agencies and private industry throughout the United States.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 5 | 768 contacts → | ||||
Partial evidence “Our mission is simple - to combat climate change through market-based, cost-effective energy, carbon, and water management solutions that make big impacts.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 6 | 727 contacts → | ||||
Indirect evidence “We’re on a mission to make power personal.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 7 | 724 contacts → | ||||
Partial evidence “Resource Innovations (RI) is an energy transformation firm.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 8 | 452 contacts → | ||||
Indirect evidence “We are Groundwater & Environmental Services, Inc, better known as GES.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 9 | 382 contacts → | ||||
Partial evidence “We are Trio – built from Edison Energy, Alfa Energy, and Altenex Energy.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 10 | 376 contacts → | ||||
Indirect evidence “Established in 2019.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 11 | 370 contacts → | ||||
Indirect evidence “P2S has brought forward-thinking, sustainable engineering solutions to California, the Pacific Northwest, and beyond, for over 30 years.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 12 | 360 contacts → | ||||
Partial evidence “TAKKION is Moving Energy Forward.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 13 | 354 contacts → | ||||
Partial evidence “Wendel is an Architecture, Engineering, Energy Efficiency, and Construction Management Firm that delivers customized solutions and turnkey projects in innovative ways.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 14 | 335 contacts → | ||||
Partial evidence “Customized Energy Solutions is at the forefront of competitive energy markets.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 15 | 325 contacts → | ||||
Indirect evidence “3Degrees is a leading global climate solutions provider, pioneer of environmental markets, and Certified B Corporation.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 16 | 303 contacts → | ||||
Partial evidence “Environmental Consulting & Technology, Inc.(ECT) is a multi-disciplinary environmental and sustainability consulting firm delivering strategy, permitting, design, and management…” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 17 | 290 contacts → | ||||
Partial evidence “At Cascade Energy, we believe in better.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 18 | 277 contacts → | ||||
Indirect evidence “E&E is now WSP USA.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 19 | 274 contacts → | ||||
Indirect evidence “People.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 20 | 264 contacts → | ||||
Strong evidence “We provide global renewable energy consulting services, focused on empowering clients to navigate the complexities of the energy transition.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 21 | 263 contacts → | ||||
Strong evidence “Merjent is an environmental, restoration, and engineering consulting firm with a long history serving the energy industry.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 22 | 250 contacts → | ||||
Strong evidence “Mosaic is a consulting firm that delivers custom solutions across the energy, utility, grid operations, and grid modernization space.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 23 | 221 contacts → | ||||
Partial evidence “At Kleinschmidt, we work primarily with energy companies and government agencies in North America to protect and enhance the environment without compromising performance.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 24 | 212 contacts → | ||||
Partial evidence “Dalkia Energy Solutions, a subsidiary of the EDF (Électricité de France) Group, is a national leader in energy efficiency and sustainability for commercial, industrial, and…” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 25 | 211 contacts → | ||||
Partial evidence “PEG presents a comprehensive capacity for the evaluation and understanding of a broad base of energy and environmental sustainability related programs, policies and initiatives.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: green energy consulting firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names green energy consulting firms.
- Partial evidence
- Its own public description names part of green energy consulting firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name green energy consulting firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 25 of 4,315 green energy consulting firms based in the United States
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Green energy consulting firms based in the United States at a glance
As of Sep 3, 2026Companies by employee count
Freshness & accuracy
How recently the business emails on this list were verified
Email last verified
How this list was built
Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among green energy consulting firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.
- Source
- The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
- What qualifies
- Companies headquartered in the United States whose own description of what they do matches “green energy consulting firms”. Matching reads each company's description, not its industry code or its name.
- RevenueBase Smart Search
- RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names green energy consulting firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
- What we exclude
- Companies whose own description does not clearly place them among green energy consulting firms, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
- Match quality
- In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
- Ranking
- Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
- Verification
- Every listed company carries at least one verified work email, 22,256 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
- Refresh
- This page's figures were pulled from the company graph on September 3, 2026. Lists refresh periodically as the graph is re-checked.
- Corrections
- Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.
Green energy consulting firms by metro
- Green energy consulting firms in Houston184
- Green energy consulting firms in New York162
- Green energy consulting firms in Denver90
- Green energy consulting firms in Chicago86
- Green energy consulting firms in Washington84
- Green energy consulting firms in San Francisco64
- Green energy consulting firms in Austin63
Frequently asked
What is RevenueBase Smart Search?
RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names green energy consulting firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.
How many green energy consulting firms are there based in the United States?
RevenueBase identified 4,315 green energy consulting firms headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.
What is the largest company on this list?
Westwood Professional Services, headquartered in Lake Charles, tops this list with the largest team on record.
Which city has the most green energy consulting firms?
Houston leads with 184 headquartered companies, followed by New York (162) and Denver (90).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 22,256 verified decision-maker contacts tracked across these 4,315 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 3, 2026.
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About this data
RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.
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