Company lists · Data refreshed September 2026

Top 25 Clean energy consultants based in Washington, United States

RevenueBase identified 73 clean energy consultants headquartered in Washington, United States as of September 2026 and tracks 805 professional contacts across them, including 436 with verified work emails. Houston is the largest hub.

This list covers clean energy consultants 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 16, 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 16, 2026 86% judged on-target in blind review
73Companies
805Contacts tracked
436Verified emails
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The 25 largest clean energy consultants based in Washington, United States

Ranked by team size
Top 25 of 73 clean energy consultants based in Washington, United States, ranked by team size, largest first. Data refreshed Sep 16, 2026. RevenueBase Smart Search rates how each company's information relates to clean energy consultants: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceWashington, DC, United StatesHQ checked Sep 16, 202651-200434 contacts →

Indirect evidence

“Synergy Consulting is Global Leader in Financial and Corporate Advisory.”

Source: RevenueBase Database · checked Sep 16, 2026
2Indirect evidenceWashington, DC, United StatesHQ checked Sep 16, 202651-20063 contacts →

Indirect evidence

“Baumann Consulting is driven to deliver solutions for a carbon-neutral real estate industry.”

Source: RevenueBase Database · checked Sep 16, 2026
3Indirect evidenceWashington, United StatesHQ checked Sep 16, 202611-5024 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 16, 2026
4Partial evidenceWashington, DC, United StatesHQ checked Sep 16, 20261-1018 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 16, 2026
5Strong evidenceWashington, DC, United StatesHQ checked Sep 16, 202611-5017 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 16, 2026
6Strong evidenceWashington, DC, United StatesHQ checked Sep 16, 202651-20017 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 16, 2026
7Indirect evidenceWashington, DC, United StatesHQ checked Sep 16, 202611-5015 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 16, 2026
8Indirect evidenceWashington, DC, United StatesHQ checked Sep 16, 20261-1014 contacts →

Indirect evidence

“CO2EFFICIENT LLC (COEFFICIENT) was founded in 2017 as a mission-focused Washington, D.C.”

Source: RevenueBase Database · checked Sep 16, 2026
9Indirect evidenceWashington, DC, United StatesHQ checked Sep 16, 202651-20014 contacts →

Indirect 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 16, 2026
10Indirect evidenceWashington, DC, United StatesHQ checked Sep 16, 20261-1011 contacts →

Indirect 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 16, 2026
11Partial evidenceWashington, DC, United StatesHQ checked Sep 16, 202611-5011 contacts →

Partial evidence

“S2 Strategies is an energy advisory firm founded in 2023 by Sam Ricketts and Shara Mohtadi.”

Source: RevenueBase Database · checked Sep 16, 2026
12Indirect evidenceWashington, DC, United StatesHQ checked Sep 16, 202611-509 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 16, 2026
13Indirect evidenceWashington, DC, United StatesHQ checked Sep 16, 20261-108 contacts →

Indirect evidence

“Green Strategies Inc.”

Source: RevenueBase Database · checked Sep 16, 2026
14Indirect evidenceWashington, DC, United StatesHQ checked Sep 16, 202611-507 contacts →

Indirect 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 16, 2026
15Partial evidenceWashington, United StatesHQ checked Sep 16, 20261-107 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 16, 2026
16Partial evidenceWashington, DC, United StatesHQ checked Sep 16, 20261-106 contacts →

Partial 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 16, 2026
17Strong evidenceWashington, DC, United StatesHQ checked Sep 16, 202611-506 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 16, 2026
18Indirect evidenceWashington, DC, United StatesHQ checked Sep 16, 20261-105 contacts →

Indirect evidence

“38 North Solutions is a boutique consulting firm that provides a suite of business strategy and public policy services to innovative businesses and organizations.”

Source: RevenueBase Database · checked Sep 16, 2026
19Indirect evidenceWashington, DC, United StatesHQ checked Sep 16, 20261-105 contacts →

Indirect evidence

“Alt Surya is a global climate advisory firm, which provides expert consulting services to clients in Asia and North America.”

Source: RevenueBase Database · checked Sep 16, 2026
20Partial evidenceWashington, United StatesHQ checked Sep 16, 20261-105 contacts →

Partial 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 16, 2026
21Strong evidenceWashington, DC, United StatesHQ checked Sep 16, 20261-105 contacts →

Strong evidence

“Our team leverages deep industry expertise to help you navigate regulatory shifts and seize new opportunities in clean energy.”

Source: RevenueBase Database · checked Sep 16, 2026
22Indirect evidenceWashington, DC, United StatesHQ checked Sep 16, 20261-104 contacts →

Indirect evidence

“Leading and innovative company that finding solutions, bridging gaps and driving positive action for clients and the planet.”

Source: RevenueBase Database · checked Sep 16, 2026
23Partial evidenceWashington, DC, United StatesHQ checked Sep 16, 20261-104 contacts →

Partial evidence

“Lightbox Energy is an energy and sustainability program management firm.”

Source: RevenueBase Database · checked Sep 16, 2026
24Partial evidenceWashington, DC, United StatesHQ checked Sep 16, 20261-104 contacts →

Partial evidence

“Range Renewable Advisors (“Range” or “Range Renewables”) is a renewable energy advisory firm focused on helping clients tackle complex financial solutions in development, project…”

Source: RevenueBase Database · checked Sep 16, 2026
25Partial evidenceWashington, DC, United StatesHQ checked Sep 16, 202611-504 contacts →

Partial evidence

“A full service Development, Construction and Management Firm Development, Energy Efficiency, Benchmarking, Program Management, Development Consulting, Construction Management…”

Source: RevenueBase Database · checked Sep 16, 2026

Showing 25 of 73 clean energy consultants based in Washington, United States

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Clean energy consultants based in Washington, United States at a glance

As of Sep 16, 2026
54.2%Verified-email coverage
11.0Average contacts per company
1-10Median size (employees)
171.2%Largest-city concentration · Houston
Sep 16, 2026Page data refreshed

Companies by employee count

1-10
51
11-50
17
51-200
5

Email recency for this list is measured across the whole United States list rather than for Washington, so it is reported there. Company counts and contact totals on this page are exact for Washington, over 73 companies.

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 consultants, 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 consultants”. 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 consultants), 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 consultants, 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, 436 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 16, 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.

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 consultants, 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 consultants are there based in Washington, United States?

RevenueBase identified 73 clean energy consultants 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 consultants?

Houston leads with 125 headquartered companies, followed by New York (115) and Washington (73).

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 436 verified decision-maker contacts tracked across these 73 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 16, 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.