Company lists · Data refreshed September 2026

Top 25 Energy efficiency retrofit companies based in the United States

Name: Energy efficiency retrofit companies based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 16, 2026 1,689 companies tracked

RevenueBase identified 1,689 energy efficiency retrofit companies headquartered in the United States as of September 2026 and tracks 25,979 professional contacts across them, including 12,218 with verified work emails. New York is the largest hub.

This list covers energy efficiency retrofit companies 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 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

1,689Companies

25,979Contacts tracked

12,218Verified emails

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The 25 largest energy efficiency retrofit companies based in the United States

Ranked by team size

Top 25 of 1,689 energy efficiency retrofit companies based in the United States, ranked by team size, largest first. Data refreshed Sep 16, 2026. RevenueBase Smart Search rates how each company's information relates to energy efficiency retrofit companies: 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Mckinstry	Partial evidence	Seattle, WA, United StatesHQ checked Sep 16, 2026	1,001-5,000	2,213 contacts →
	Partial evidence “We're a national construction and energy services company dedicated to innovating the waste and climate harm out of the built environment.” Source: RevenueBase Database · checked Sep 16, 2026
2	Clearesult	Strong evidence	Austin, TX, United StatesHQ checked Sep 16, 2026	1,001-5,000	2,121 contacts →
	Strong evidence “CLEAResult is the largest provider of energy efficiency, energy transition and energy sustainability services in North America.” Source: RevenueBase Database · checked Sep 16, 2026
3	Ameresco	Partial evidence	Framingham, MA, United StatesHQ checked Sep 16, 2026	1,001-5,000	1,383 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 16, 2026
4	Albireo Energy	Partial evidence	Edison, NJ, United StatesHQ checked Sep 16, 2026	1,001-5,000	669 contacts →
	Partial evidence “Albireo Energy is a leading independent building controls and energy services provider recognized by customers for creating intelligent, high-performance buildings.” Source: RevenueBase Database · checked Sep 16, 2026
5	Noresco	Partial evidence	Westborough, MA, United StatesHQ checked Sep 16, 2026	201-500	481 contacts →
	Partial evidence “NORESCO, a part of Carrier Global Corporation, helps customers modernize aging building systems and upgrade energy and water infrastructure to meet evolving demands.” Source: RevenueBase Database · checked Sep 16, 2026
6	Sitelogiq	Indirect evidence	Minneapolis, MN, United StatesHQ checked Sep 16, 2026	501-1,000	450 contacts →
	Indirect evidence “SitelogIQ provides design, engineering, and construction management services that help organizations nationwide modernize their facilities and infrastructure.” Source: RevenueBase Database · checked Sep 16, 2026
7	Veregy	Partial evidence	Phoenix, MO, United StatesHQ checked Sep 16, 2026	501-1,000	383 contacts →
	Partial evidence “Veregy is an award-winning NAESCO-Accredited decarbonization company focusing on accelerating and simplifying the Energy Transition.” Source: RevenueBase Database · checked Sep 16, 2026
8	Budderfly	Strong evidence	Shelton, CT, United StatesHQ checked Sep 16, 2026	201-500	366 contacts →
	Strong evidence “Budderfly is redefining how energy efficiency, resilience, and grid participation can work together across America’s commercial sector.” Source: RevenueBase Database · checked Sep 16, 2026
9	Homeworks Energy, INC	Strong evidence	Medford, MA, United StatesHQ checked Sep 16, 2026	201-500	356 contacts →
	Strong evidence “At HomeWorks Energy, our mission is simple, literally: Energy Efficiency, Simplified.” Source: RevenueBase Database · checked Sep 16, 2026
10	Cascade Energy	Partial evidence	Portland, OR, United StatesHQ checked Sep 16, 2026	201-500	288 contacts →
	Partial evidence “At Cascade Energy, we believe in better.” Source: RevenueBase Database · checked Sep 16, 2026
11	Lime Energy	Partial evidence	Newark, NJ, United StatesHQ checked Sep 16, 2026	201-500	233 contacts →
	Partial evidence “Lime Energy is building a new energy future.” Source: RevenueBase Database · checked Sep 16, 2026
12	PEG	Partial evidence	Fairfax, VA, United StatesHQ checked Sep 16, 2026	201-500	214 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 16, 2026
13	Dalkia Energy Solutions	Strong evidence	Beverly, MA, United StatesHQ checked Sep 16, 2026	201-500	210 contacts →
	Strong 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 16, 2026
14	Bright Power	Strong evidence	New York, NY, United StatesHQ checked Sep 16, 2026	51-200	205 contacts →
	Strong evidence “Bright Power is a leading provider of energy efficiency and decarbonization solutions for the real estate industry.” Source: RevenueBase Database · checked Sep 16, 2026
15	Energy Management Collaborative EMC	Strong evidence	Minneapolis, MN, United StatesHQ checked Sep 16, 2026	201-500	193 contacts →
	Strong evidence “EMC manages and scales turnkey energy efficiency solutions for Fortune 500 clients across their North American portfolios.” Source: RevenueBase Database · checked Sep 16, 2026
16	Frontier Energy, INC	Partial evidence	Pleasanton, CA, United StatesHQ checked Sep 16, 2026	51-200	192 contacts →
	Partial evidence “Frontier Energy is a professional services firm that excels in market transformation.” Source: RevenueBase Database · checked Sep 16, 2026
17	Mcclure Company	Partial evidence	Harrisburg, PA, United StatesHQ checked Sep 16, 2026	201-500	166 contacts →
	Partial evidence “Headquartered in Harrisburg, Pennsylvania, McClure Company is one of the mid-Atlantic's largest, fully integrated mechanical construction, engineering, maintenance and energy…” Source: RevenueBase Database · checked Sep 16, 2026
18	Syserco, INC	Partial evidence	Fremont, CA, United StatesHQ checked Sep 16, 2026	51-200	164 contacts →
	Partial evidence “Syserco is an industry leader delivering Energy Management Solutions and Services to commercial and industrial facilities ranging from K-12 Schools, to High Rises, to…” Source: RevenueBase Database · checked Sep 16, 2026
19	RISE	Strong evidence	Cranston, RI, United StatesHQ checked Sep 16, 2026	201-500	151 contacts →
	Strong evidence “RISE is a pioneer in the delivery of turnkey energy-efficiency services for residential, commercial and industrial facilities.” Source: RevenueBase Database · checked Sep 16, 2026
20	Concord Engineering Group, INC	Indirect evidence	Voorhees, NJ, United StatesHQ checked Sep 16, 2026	51-200	135 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 16, 2026
21	Willdan Performance Engineering	Partial evidence	Denver, KS, United StatesHQ checked Sep 16, 2026	51-200	129 contacts →
	Partial evidence “Willdan Performance Engineering specializes in energy and infrastructure improvement projects through design-build and performance contracting.” Source: RevenueBase Database · checked Sep 16, 2026
22	Cypress Envirosystems	Indirect evidence	San Jose, CA, United StatesHQ checked Sep 16, 2026	11-50	128 contacts →
	Indirect evidence “We Make Buildings Brilliant.” Source: RevenueBase Database · checked Sep 16, 2026
23	Synergy Companies	Strong evidence	Fresno, CA, United StatesHQ checked Sep 16, 2026	501-1,000	124 contacts →
	Strong evidence “Synergy Companies is the largest energy services companies in California and provides a comprehensive approach to energy efficiency and environmental solutions in both the…” Source: RevenueBase Database · checked Sep 16, 2026
24	Michaels Energy- An Inc. 5000 Company	Partial evidence	La Crosse, WI, United StatesHQ checked Sep 16, 2026	51-200	121 contacts →
	Partial evidence “Michaels Energy is a veteran-owned energy consulting firm that exists to help businesses minimize waste and maximize value.” Source: RevenueBase Database · checked Sep 16, 2026
25	Scale Microgrids	Partial evidence	Ridgewood, NJ, United StatesHQ checked Sep 16, 2026	51-200	119 contacts →
	Partial evidence “The future of humanity is dependent on making our energy infrastructure cleaner, more affordable, and more resilient.” Source: RevenueBase Database · checked Sep 16, 2026

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: energy efficiency retrofit companies. 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 energy efficiency retrofit companies.
Partial evidence: Its own public description names part of energy efficiency retrofit companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name energy efficiency retrofit companies. 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 1,689 energy efficiency retrofit companies based in the United States

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Energy efficiency retrofit companies based in the United States at a glance

As of Sep 16, 2026

47.0%Verified-email coverage

15.4Average contacts per company

1-10Median size (employees)

3.7%Largest-city concentration · New York

Sep 16, 2026Page data refreshed

Companies by employee count

1-10

859

11-50

614

51-200

164

201-500

501-1,000

1,001-5,000

10001+

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 1,689 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 energy efficiency retrofit companies, 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 “energy efficiency retrofit companies”. 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 energy efficiency retrofit companies), 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 energy efficiency retrofit companies, 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, 12,218 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.

Energy efficiency retrofit companies by metro

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 energy efficiency retrofit companies, 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 energy efficiency retrofit companies are there based in the United States?

RevenueBase identified 1,689 energy efficiency retrofit companies 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?

Mckinstry, headquartered in Seattle, tops this list with the largest team on record.

Which city has the most energy efficiency retrofit companies?

New York leads with 63 headquartered companies, followed by Atlanta (28) and Houston (28).

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 12,218 verified decision-maker contacts tracked across these 1,689 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.