Company lists · Data refreshed September 2026

Top 25 Residential energy efficiency companies based in the United States

RevenueBase identified 3,439 residential energy efficiency companies headquartered in the United States as of September 2026 and tracks 54,001 professional contacts across them, including 17,777 with verified work emails. Houston is the largest hub.

This list covers residential energy efficiency 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 17, 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 17, 2026 86% judged on-target in blind review
3,439Companies
54,001Contacts tracked
17,777Verified emails
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The 25 largest residential energy efficiency companies based in the United States

Ranked by team size
Top 25 of 3,439 residential energy efficiency companies based in the United States, ranked by team size, largest first. Data refreshed Sep 17, 2026. RevenueBase Smart Search rates how each company's information relates to residential energy efficiency 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.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Partial evidenceWaukesha, WI, United StatesHQ checked Sep 17, 20265,001-10,0003,797 contacts →

Partial evidence

“Generac is the total energy solutions company powering a smarter world.”

Source: RevenueBase Database · checked Sep 17, 2026
2Strong evidenceAustin, TX, United StatesHQ checked Sep 17, 20261,001-5,0002,121 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 17, 2026
3Partial evidenceDublin, OH, United StatesHQ checked Sep 17, 20261,001-5,0001,388 contacts →

Partial evidence

“IGS Energy has been a trusted energy advisor since 1989, growing into one of the nation’s top energy retailers.”

Source: RevenueBase Database · checked Sep 17, 2026
4Partial evidenceFramingham, MA, United StatesHQ checked Sep 17, 20261,001-5,0001,383 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 17, 2026
5Partial evidenceOrem, UT, United StatesHQ checked Sep 17, 20261,001-5,0001,168 contacts →

Partial evidence

“Blue Raven Solar, a SunPower Company, is a retailer of residential home solar systems.”

Source: RevenueBase Database · checked Sep 17, 2026
6Indirect evidenceProvo, UT, United StatesHQ checked Sep 17, 2026501-1,000912 contacts →

Indirect evidence

“Ion Solar is a premium, full-service solar provider.”

Source: RevenueBase Database · checked Sep 17, 2026
7Partial evidenceHouston, TX, United StatesHQ checked Sep 17, 2026501-1,000906 contacts →

Partial evidence

“Sunnova Energy International Inc.(NYSE: NOVA) is an industry-leading energy services company focused on making clean energy more accessible, reliable, and affordable for…”

Source: RevenueBase Database · checked Sep 17, 2026
8Indirect evidenceLehi, UT, United StatesHQ checked Sep 17, 20265,001-10,000719 contacts →

Indirect evidence

“We’re on a mission to make power personal.”

Source: RevenueBase Database · checked Sep 17, 2026
9Partial evidenceCharlotte, NC, United StatesHQ checked Sep 17, 2026201-500539 contacts →

Partial evidence

“Palmetto is a leading clean tech company on a mission to accelerate the transition to a clean energy future.”

Source: RevenueBase Database · checked Sep 17, 2026
10Strong evidenceSt. Rose, LA, United StatesHQ checked Sep 17, 2026501-1,000507 contacts →

Strong evidence

“PosiGen is the nation's leading residential solar and energy efficiency provider.”

Source: RevenueBase Database · checked Sep 17, 2026
11Partial evidenceWestborough, MA, United StatesHQ checked Sep 17, 2026201-500481 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 17, 2026
12Partial evidenceHouston, TX, United StatesHQ checked Sep 17, 2026501-1,000389 contacts →

Partial evidence

“ARCXIS (Formerly DPIS Builder Services), is the largest provider of HERS inspections, ENERGY STAR ratings, engineering and design, construction quality assurance and other builder…”

Source: RevenueBase Database · checked Sep 17, 2026
13Partial evidenceIrvine, CA, United StatesHQ checked Sep 17, 2026201-500370 contacts →

Partial evidence

“Supernova embodies the spirit of innovation and dedication to a sustainable future, making it a shining example of what it means to be a leader in the renewable energy industry.”

Source: RevenueBase Database · checked Sep 17, 2026
14Partial evidenceEl Dorado Hills, CA, United StatesHQ checked Sep 17, 2026201-500368 contacts →

Partial evidence

“V3 was founded as a response to the stagnation within the energy industry.”

Source: RevenueBase Database · checked Sep 17, 2026
15Strong evidenceShelton, CT, United StatesHQ checked Sep 17, 2026201-500366 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 17, 2026
16Strong evidenceMedford, MA, United StatesHQ checked Sep 17, 2026201-500356 contacts →

Strong evidence

“At HomeWorks Energy, our mission is simple, literally: Energy Efficiency, Simplified.”

Source: RevenueBase Database · checked Sep 17, 2026
17Indirect evidencePhoenix, AZ, United StatesHQ checked Sep 17, 2026201-500351 contacts →

Indirect evidence

“https://ourworldenergy.com/”

Source: RevenueBase Database · checked Sep 17, 2026
18Indirect evidenceEl Cajon, CA, United StatesHQ checked Sep 17, 2026501-1,000337 contacts →

Indirect evidence

“Ranked #1 in Solar + Battery Installation in America by "Solar Power World" Go Solar American Style!#1 Veteran Owned Solar Company in California Solar Panels.”

Source: RevenueBase Database · checked Sep 17, 2026
19Partial evidenceMedford, OR, United StatesHQ checked Sep 17, 202651-200300 contacts →

Partial evidence

“Founded in 2017, Purelight Power has quickly grown to be one of the nations largest residential solar installer.”

Source: RevenueBase Database · checked Sep 17, 2026
20Partial evidenceVerona, WI, United StatesHQ checked Sep 17, 202651-200294 contacts →

Partial evidence

“Everlight Solar provides homeowners with simple and affordable clean energy.”

Source: RevenueBase Database · checked Sep 17, 2026
21Indirect evidencePensacola, FL, United StatesHQ checked Sep 17, 20261,001-5,000275 contacts →

Indirect evidence

“People.”

Source: RevenueBase Database · checked Sep 17, 2026
22Partial evidenceZionsville, IN, United StatesHQ checked Sep 17, 202651-200260 contacts →

Partial evidence

“A pioneering dealer for next-generation windows and eco-friendly building products, Apex Energy Solutions serves homeowners who value and love the place they call home.”

Source: RevenueBase Database · checked Sep 17, 2026
23Partial evidenceRocklin, CA, United StatesHQ checked Sep 17, 2026201-500258 contacts →

Partial evidence

“Infinity Energy, we exist to power you At Infinity Energy we connect people to clean energy and customized home solutions.”

Source: RevenueBase Database · checked Sep 17, 2026
24Strong evidenceFort Washington, PA, United StatesHQ checked Sep 17, 2026201-500252 contacts →

Strong evidence

“CMC Energy Services is a woman-owned full-service energy efficiency company with nearly 50 years of experience delivering value-based energy conservation services.”

Source: RevenueBase Database · checked Sep 17, 2026
25Partial evidenceHyannis, MA, United StatesHQ checked Sep 17, 2026201-500250 contacts →

Partial evidence

“Savant is a global leader in smart home and energy, and traditional lighting solutions, for consumers, businesses, utility companies and more.”

Source: RevenueBase Database · checked Sep 17, 2026

Showing 25 of 3,439 residential energy efficiency companies based in the United States

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Residential energy efficiency companies based in the United States at a glance

As of Sep 17, 2026
32.9%Verified-email coverage
15.7Average contacts per company
11-50Median size (employees)
2.1%Largest-city concentration · Houston
Sep 17, 2026Page data refreshed

Companies by employee count

1-10
1,582
11-50
1,315
51-200
398
201-500
88
501-1,000
26
1,001-5,000
13
5,001-10,000
4
10001+
3

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 3,439 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 residential energy efficiency 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 “residential energy efficiency 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 residential energy efficiency 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 residential energy efficiency 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, 17,777 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 17, 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 residential energy efficiency 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 residential energy efficiency companies are there based in the United States?

RevenueBase identified 3,439 residential energy efficiency 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?

Generac, headquartered in Waukesha, tops this list with the largest team on record.

Which city has the most residential energy efficiency companies?

Houston leads with 72 headquartered companies, followed by New York (69) and Austin (45).

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 17,777 verified decision-maker contacts tracked across these 3,439 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 17, 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.