Company lists · Data refreshed September 2026

Top 25 Geothermal system companies based in the United States

Name: Geothermal system 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 20, 2026 1,034 companies tracked

RevenueBase identified 1,034 geothermal system companies headquartered in the United States as of September 2026 and tracks 13,641 professional contacts across them, including 5,481 with verified work emails. Houston is the largest hub.

This list covers geothermal system 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 20, 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 20, 2026 86% judged on-target in blind review

1,034Companies

13,641Contacts tracked

5,481Verified emails

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The 25 largest geothermal system companies based in the United States

Ranked by team size

Top 25 of 1,034 geothermal system companies based in the United States, ranked by team size, largest first. Data refreshed Sep 20, 2026. RevenueBase Smart Search rates how each company's information relates to geothermal system 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	Calpine	Partial evidence	Houston, TX, United StatesHQ checked Sep 20, 2026	1,001-5,000	2,112 contacts →
	Partial evidence “A business unit of Constellation (NASDAQ: CEG), Calpine Corporation is America’s largest generator of electricity from natural gas and geothermal resources with operations in…” Source: RevenueBase Database · checked Sep 20, 2026
2	Ormat Technologies, INC	Indirect evidence	Reno, NV, United StatesHQ checked Sep 20, 2026	1,001-5,000	1,281 contacts →
	Indirect evidence “With over five decades of experience, Ormat Technologies, Inc.” Source: RevenueBase Database · checked Sep 20, 2026
3	Grupo IPS	Indirect evidence	Conroe, TX, United StatesHQ checked Sep 20, 2026	51-200	245 contacts →
	Indirect evidence “IPS is an integrated oilfield service company with over 20 years in the business.” Source: RevenueBase Database · checked Sep 20, 2026
4	Waterfurnace International	Indirect evidence	Fort Wayne, IN, United StatesHQ checked Sep 20, 2026	201-500	224 contacts →
	Indirect evidence “WaterFurnace International, Inc.” Source: RevenueBase Database · checked Sep 20, 2026
5	Tolin Mechanical Systems	Indirect evidence	Denver, CO, United StatesHQ checked Sep 20, 2026	201-500	220 contacts →
	Indirect evidence “Tolin Mechanical is a Leading Energy & Commercial HVAC Services Company.” Source: RevenueBase Database · checked Sep 20, 2026
6	Fervo Energy	Partial evidence	Houston, CA, United StatesHQ checked Sep 20, 2026	51-200	213 contacts →
	Partial evidence “Fervo Energy provides 24/7 carbon-free energy through the development of next-generation geothermal power.” Source: RevenueBase Database · checked Sep 20, 2026
7	Haller Enterprises	Indirect evidence	Lititz, PA, United StatesHQ checked Sep 20, 2026	201-500	191 contacts →
	Indirect evidence “Since 1981, Haller Enterprises has proudly served central and eastern Pennsylvania as a leader in heating, cooling, plumbing, and electrical services.” Source: RevenueBase Database · checked Sep 20, 2026
8	Hill York	Indirect evidence	Dania Beach, FL, United StatesHQ checked Sep 20, 2026	201-500	168 contacts →
	Indirect evidence “Hill York is a full service contractor that offers a full array of energy efficient air-conditioning services from concept to completion, maintenance to repair and everything in…” Source: RevenueBase Database · checked Sep 20, 2026
9	Suntria	Indirect evidence	Phoenix, AZ, United StatesHQ checked Sep 20, 2026	51-200	126 contacts →
	Indirect evidence “Suntria is the deployment engine of EverPower.AI.” Source: RevenueBase Database · checked Sep 20, 2026
10	Dandelion Energy	Partial evidence	Mount Kisco, NY, United StatesHQ checked Sep 20, 2026	51-200	118 contacts →
	Partial evidence “Dandelion Energy is the nation’s leading residential geothermal provider, on a mission to make the world’s most efficient heating and cooling technology accessible to everyone.” Source: RevenueBase Database · checked Sep 20, 2026
11	Midwest Mechanical Commercial, Industrial Hvac Mechanical Services	Indirect evidence	Lombard, IL, United StatesHQ checked Sep 20, 2026	51-200	110 contacts →
	Indirect evidence “Chicago's Facilities Management Company Midwest Mechanical is a commercial HVAC services and facility management company focused on energy efficiency for building owners and…” Source: RevenueBase Database · checked Sep 20, 2026
12	Encon Heating & A C	Indirect evidence	Stratford, CT, United StatesHQ checked Sep 20, 2026	201-500	110 contacts →
	Indirect evidence “At ENCON, we take care of people.” Source: RevenueBase Database · checked Sep 20, 2026
13	Brightcore Energy	Indirect evidence	Armonk, NY, United StatesHQ checked Sep 20, 2026	51-200	108 contacts →
	Indirect evidence “Brightcore Energy is a leading renewable energy solutions provider serving commercial, institutional, and government clients.” Source: RevenueBase Database · checked Sep 20, 2026
14	Robison	Indirect evidence	Port Chester, NY, United StatesHQ checked Sep 20, 2026	51-200	92 contacts →
	Indirect evidence “For more than 100 years, Robison has been a staple in Westchester and Putnam counties, servicing nearly homes while earning an A+ from the Better Business Bureau.” Source: RevenueBase Database · checked Sep 20, 2026
15	AIR Mechanical INC	Indirect evidence	Ham Lake, MN, United StatesHQ checked Sep 20, 2026	51-200	87 contacts →
	Indirect evidence “Creating Custom Comfort since 1985!” Source: RevenueBase Database · checked Sep 20, 2026
16	HALCO	Indirect evidence	Phelps, NY, United StatesHQ checked Sep 20, 2026	51-200	82 contacts →
	Indirect evidence “Halco is a highly accredited, national award-winning contractor that has been providing high-quality solutions to residential and commercial clients since 1984.” Source: RevenueBase Database · checked Sep 20, 2026
17	Enertech Global, LLC	Partial evidence	Greenville, IL, United StatesHQ checked Sep 20, 2026	51-200	81 contacts →
	Partial evidence “Enertech Global is a leading manufacturer and visionary in the geothermal heating and cooling industry.” Source: RevenueBase Database · checked Sep 20, 2026
18	Hayden Industrial	Indirect evidence	Tulsa, OK, United StatesHQ checked Sep 20, 2026	201-500	81 contacts →
	Indirect evidence “Hayden is a technology and engineering company that builds critical infrastructure for compute, energy and thermal performance.” Source: RevenueBase Database · checked Sep 20, 2026
19	Elitaire	Indirect evidence	Cincinnati, OH, United StatesHQ checked Sep 20, 2026	11-50	74 contacts →
	Indirect evidence “ElitAire - Technical experts in energy-optimized building solutions.” Source: RevenueBase Database · checked Sep 20, 2026
20	Energy 1	Partial evidence	Bozeman, MT, United StatesHQ checked Sep 20, 2026	201-500	72 contacts →
	Partial evidence “Energy 1 designs and installs state-of-the-art Mechanical, Electrical, and Plumbing systems that utilize renewable technologies and deliver efficiency, elegance, and legacies our…” Source: RevenueBase Database · checked Sep 20, 2026
21	Cyrq Energy	Partial evidence	Salt Lake City, UT, United StatesHQ checked Sep 20, 2026	51-200	69 contacts →
	Partial evidence “With over a decade of experience in the development of clean, efficient renewable energy facilities, Cyrq owns, operates and develops geothermal and solar energy-based power…” Source: RevenueBase Database · checked Sep 20, 2026
22	Alpine Home AIR	Indirect evidence	Chicago, IL, United StatesHQ checked Sep 20, 2026	51-200	68 contacts →
	Indirect evidence “Founded in 2002, Alpine is a team of forward-thinking innovators working to provide intelligent heating and cooling solutions to homeowners in a way that:* Leads Americans away…” Source: RevenueBase Database · checked Sep 20, 2026
23	Thermal Resource Solutions, A Coolsys Company	Partial evidence	Kernersville, NC, United StatesHQ checked Sep 20, 2026	51-200	68 contacts →
	Partial evidence “Thermal Resource Solutions specializes in complex, custom, and energy-efficient mechanical and plumbing systems.” Source: RevenueBase Database · checked Sep 20, 2026
24	Roscoe Brown, INC	Indirect evidence	Murfreesboro, TN, United StatesHQ checked Sep 20, 2026	51-200	65 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 20, 2026
25	Quaise Energy	Partial evidence	Houston, MA, United StatesHQ checked Sep 20, 2026	51-200	62 contacts →
	Partial evidence “Quaise develops superhot geothermal power plants for a terawatt-scale world.” Source: RevenueBase Database · checked Sep 20, 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: geothermal system 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 geothermal system companies.
Partial evidence: Its own public description names part of geothermal system companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name geothermal system 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 1,034 geothermal system companies based in the United States

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Geothermal system companies based in the United States at a glance

As of Sep 20, 2026

40.2%Verified-email coverage

13.2Average contacts per company

11-50Median size (employees)

2.8%Largest-city concentration · Houston

Sep 20, 2026Page data refreshed

Companies by employee count

1-10

488

11-50

414

51-200

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 1,034 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 geothermal system 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 “geothermal system 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 geothermal system 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 geothermal system 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, 5,481 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 20, 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.

Geothermal system companies by metro

Geothermal system companies in Houston29

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 geothermal system 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 geothermal system companies are there based in the United States?

RevenueBase identified 1,034 geothermal system 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?

Calpine, headquartered in Houston, tops this list with the largest team on record.

Which city has the most geothermal system companies?

Houston leads with 29 headquartered companies, followed by Denver (14) and Austin (11).

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 5,481 verified decision-maker contacts tracked across these 1,034 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 20, 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.