Company lists · Data refreshed September 2026
Top 25 Clean energy consulting firms based in Washington, United States
RevenueBase identified 109 clean energy consulting firms headquartered in Washington, United States as of September 2026 and tracks 1,107 professional contacts across them, including 589 with verified work emails and 362 with mobile numbers. Houston is the largest hub.
This list covers clean energy consulting firms headquartered in Washington, 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 8, 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 clean energy consulting firms based in Washington, United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 434 contacts → | ||||
Partial evidence “Synergy Consulting is Global Leader in Financial and Corporate Advisory.” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 2 | 155 contacts → | ||||
Partial evidence “CleanChoice Energy is a cleantech company that empowers people and businesses to easily access climate solutions.” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 3 | 63 contacts → | ||||
Partial evidence “Baumann Consulting is driven to deliver solutions for a carbon-neutral real estate industry.” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 4 | 24 contacts → | ||||
Strong evidence “Browning Environmental Communications (Browning) is an international full-service marketing communications agency specializing in clean energy and environmental sustainability.” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 5 | 24 contacts → | ||||
Indirect evidence “At Northbridge, we provide our clients with the tools and expertise to help solve complex financial, policy, and environmental challenges.” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 6 | 19 contacts → | ||||
Partial evidence “The Clark Group is an environmental policy consulting firm that provides a broad range of services to government, private and nonprofit clients.” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 7 | 18 contacts → | ||||
Partial evidence “Amis, Patel & Brewer, LLP is a boutique law firm focused on providing legal services to the renewable energy and sustainability sectors.” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 8 | 17 contacts → | ||||
Strong evidence “Grid Strategies LLC is a power sector consulting firm helping clients understand the opportunities and barriers to integrating clean energy into the electric grid.” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 9 | 17 contacts → | ||||
Strong evidence “Ipsun Solar, a Civic Renewables Company, is a leader in clean energy services based in Virginia, Washington D.C.” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 10 | 15 contacts → | ||||
Partial evidence “Mission Strategies is the premier boutique government affairs firm serving companies at the forefront of advanced energy, national security, emerging technologies, and domestic…” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 11 | 15 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 12 | 14 contacts → | ||||
Partial evidence “Sustainable Capital Advisors (SCA) is a strategy consulting and financial advisory firm focused on delivering innovative capital solutions for the sustainable infrastructure…” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 13 | 14 contacts → | ||||
Indirect evidence “CO2EFFICIENT LLC (COEFFICIENT) was founded in 2017 as a mission-focused Washington, D.C.” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 14 | 14 contacts → | ||||
Partial evidence “Sustainable You is a national strategic consulting firm in solar and sustainability serving residential and small commercial clients with a focus in the DC, Maryland and Virginia…” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 15 | 11 contacts → | ||||
Partial evidence “Sustainable Strategies DC is a government affairs and strategic consulting firm based in Washington, DC, that helps clients secure resources for community revitalization and tools…” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 16 | 11 contacts → | ||||
Partial evidence “S2 Strategies is an energy advisory firm founded in 2023 by Sam Ricketts and Shara Mohtadi.” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 17 | 9 contacts → | ||||
Indirect evidence “At Enverra, we are driven by impact, directing capital where it has the greatest effect, standing behind people with bold ideas and promoting technologies that address global…” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 18 | 8 contacts → | ||||
Indirect evidence “Green Strategies Inc.” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 19 | 7 contacts → | ||||
Indirect evidence “The Climate Board builds AI-enhanced data products for corporate climate teams, closing the gap between infrequent assessments and real-time risk.” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 20 | 7 contacts → | ||||
Partial evidence “Partnership International, Inc, founded in 1990, is an international consulting firm that provides socio-economic, regulatory, institutional, technical, commercial and financial…” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 21 | 7 contacts → | ||||
Indirect evidence “Clima Capital Partners LLC (CLIMA) advises and creates sustainable value for local economies and communities through robust climate finance solutions, managing and mitigating…” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 22 | 7 contacts → | ||||
Partial evidence “Green Capitol LLC works on sustainable development policy at the state, federal and international levels, serving clients on agriculture, energy and environment concerns via…” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 23 | 6 contacts → | ||||
Strong evidence “Energy Shrink is an environmental consulting practice specialized in sustainability and energy efficiency in buildings, that is, high-performance or green buildings.” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 24 | 6 contacts → | ||||
Strong evidence “AMALA Clean Energy Advisors includes a core group of high-caliber multi-disciplinary global experts with extensive experience and proven track records developing clean energy…” Source: RevenueBase Database · checked Sep 8, 2026Thanks. The Data Team will review it. | |||||
| 25 | 5 contacts → | ||||
Strong evidence “OASIS Energy Partners is a full-service consulting and advisory firm at the intersection of energy, environment, and climate.” Source: RevenueBase Database · checked Sep 8, 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: clean 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 clean energy consulting firms.
- Partial evidence
- Its own public description names part of clean 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 clean 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 109 clean energy consulting firms based in Washington, United States
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Clean energy consulting firms based in Washington, United States at a glance
As of Sep 8, 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 clean 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 Washington, United States whose own description of what they do matches “clean 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 clean 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 clean energy consulting firms, and records with no verified work email. Companies headquartered outside Washington 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, 589 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 8, 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.
Clean energy consulting firms by metro in the United States
- Clean energy consulting firms in Houston223
- Clean energy consulting firms in New York194
- Clean energy consulting firms in Denver96
- Clean energy consulting firms in Washington95
- Clean energy consulting firms in Chicago90
- Clean energy consulting firms in Austin79
- Clean energy consulting firms in Los Angeles69
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 clean 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 clean energy consulting firms are there based in Washington, United States?
RevenueBase identified 109 clean energy consulting firms headquartered in Washington, 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?
Synergy Consulting, INC, headquartered in Washington, tops this list with the largest team on record.
Which city has the most clean energy consulting firms?
Houston leads with 223 headquartered companies, followed by New York (194) and Denver (96).
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 589 verified decision-maker contacts tracked across these 109 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 8, 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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