Company lists · Data refreshed September 2026

Top 25 Geothermal power plant operators based in the United States

RevenueBase identified 60 geothermal power plant operators headquartered in the United States as of September 2026 and tracks 8,783 professional contacts across them, including 3,353 with verified work emails. Houston is the largest hub.

This list covers geothermal power plant operators 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
60Companies
8,783Contacts tracked
3,353Verified emails
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The 25 largest geothermal power plant operators based in the United States

Ranked by team size
Top 25 of 60 geothermal power plant operators 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 power plant operators: 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 evidenceAtlanta, GA, United StatesHQ checked Sep 20, 202610001+3,700 contacts →

Partial evidence

“GE Vernova is a planned, purpose-built global energy company that includes Power, Wind, and Electrification businesses and is supported by its accelerator businesses of Advanced…”

Source: RevenueBase Database · checked Sep 20, 2026
2Partial evidenceHouston, TX, United StatesHQ checked Sep 20, 20261,001-5,0002,112 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
3Indirect evidenceReno, NV, United StatesHQ checked Sep 20, 20261,001-5,0001,281 contacts →

Indirect evidence

“With over five decades of experience, Ormat Technologies, Inc.”

Source: RevenueBase Database · checked Sep 20, 2026
4Indirect evidenceWest Allis, WI, United StatesHQ checked Sep 20, 2026201-500208 contacts →

Indirect evidence

“Toshiba America Energy Systems Corporation (TAES), headquartered in Milwaukee, Wisconsin, with major manufacturing and services, provides turbine/generator equipment and services…”

Source: RevenueBase Database · checked Sep 20, 2026
5Indirect evidenceSan Juan, United StatesHQ checked Sep 20, 202651-20092 contacts →

Indirect evidence

“Somos una compañía formada por profesionales altamente calificados, fundada en el año 2010 con más de 10 años de experiencia en el mercado, dedicados a la Fabricación, Diseño…”

Source: RevenueBase Database · checked Sep 20, 2026
6Partial evidencePalo Alto, CA, United StatesHQ checked Sep 20, 202611-5034 contacts →

Partial evidence

“XGS Energy is a geothermal energy company founded and headquartered in Palo Alto, CA.”

Source: RevenueBase Database · checked Sep 20, 2026
7Partial evidenceOklahoma City, OK, United StatesHQ checked Sep 20, 202611-5023 contacts →

Partial evidence

“About GreenFire Energy GreenFire Energy engineers next-generation geothermal systems designed for real-world operating conditions.”

Source: RevenueBase Database · checked Sep 20, 2026
8Indirect evidenceBakersfield, CA, United StatesHQ checked Sep 20, 202611-5015 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 20, 2026
9Indirect evidenceReno, United StatesHQ checked Sep 20, 202651-20015 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 20, 2026
10Indirect evidenceGermantown, MD, United StatesHQ checked Sep 20, 202611-5013 contacts →

Indirect evidence

“Dewhurst Group (DG) is an energy exploration and development company.”

Source: RevenueBase Database · checked Sep 20, 2026
11Partial evidenceBaltimore, MD, United StatesHQ checked Sep 20, 202611-5012 contacts →

Partial evidence

“In the 30 years of operation, Chesapeake Geosystems has earned a reputation as a geothermal contracting firm that delivers projects on time and on budget.”

Source: RevenueBase Database · checked Sep 20, 2026
12Strong evidenceOntario, CA, United StatesHQ checked Sep 20, 202651-20012 contacts →

Strong evidence

“Turbine Repair Services, LLC is the quality company for plant maintenance and overhaul needs, a single-source provider of turn-key power plant services.”

Source: RevenueBase Database · checked Sep 20, 2026
13Indirect evidenceFort Worth, United StatesHQ checked Sep 20, 202611-5011 contacts →

Indirect evidence

“At Win-Sam, we operate and maintain our clients’ energy conversion facilities to produce steam, chilled water, and electricity.”

Source: RevenueBase Database · checked Sep 20, 2026
14Partial evidenceBallston Spa, NY, United StatesHQ checked Sep 20, 202611-5010 contacts →

Partial evidence

“Aztech Geothermal, LLC offers a comprehensive solution for renewable geothermal heating and cooling systems in residential and commercial buildings with recognized expertise in…”

Source: RevenueBase Database · checked Sep 20, 2026
15Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 20, 202611-5010 contacts →

Indirect evidence

“Veizades and Associates, INC.”

Source: RevenueBase Database · checked Sep 20, 2026
16Partial evidenceDallas, TX, United StatesHQ checked Sep 20, 202611-509 contacts →

Partial evidence

“GTW Designs, Constructs & Operates Econimic NEXT GEOTHERMAL SYSTEMS: •‘Deep Decarbonized’ High Heat for Industry Clients using >220 Deg C • Direct baseload high heat (MMBTU) & MWe…”

Source: RevenueBase Database · checked Sep 20, 2026
17Indirect evidenceHouston, TX, United StatesHQ checked Sep 20, 20261-108 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 20, 2026
18Partial evidenceAustin, TX, United StatesHQ checked Sep 20, 202611-508 contacts →

Partial evidence

“Exceed Geo Energy is a privately held clean energy company redefining what’s possible with geothermal.”

Source: RevenueBase Database · checked Sep 20, 2026
19Strong evidenceDenver, CO, United StatesHQ checked Sep 20, 20261-106 contacts →

Strong evidence

“Gradient Geothermal is revolutionizing the energy landscape by harnessing geothermal heat from existing oil and gas wells to generate emissions-free power.”

Source: RevenueBase Database · checked Sep 20, 2026
20Strong evidencePalo Alto, CA, United StatesHQ checked Sep 20, 20261-104 contacts →

Strong evidence

“At Baseload Power U.S, we develop and operate geothermal power projects that deliver reliable, domestic energy around the clock – unaffected by weather, season, or time of day.”

Source: RevenueBase Database · checked Sep 20, 2026
21Partial evidenceBakersfield, CA, United StatesHQ checked Sep 20, 202611-503 contacts →

Partial evidence

“California based geothermal and oilfield service company.”

Source: RevenueBase Database · checked Sep 20, 2026
22Indirect evidenceReno, NV, United StatesHQ checked Sep 20, 20261-103 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 20, 2026
23Partial evidenceHouston, TX, United StatesHQ checked Sep 20, 20261-103 contacts →

Partial evidence

“Criterion Energy Partners (CEP) is an independent exploration and production company focused on developing decentralized direct geothermal energy projects to help commercial and…”

Source: RevenueBase Database · checked Sep 20, 2026
24Indirect evidenceHouston, TX, United StatesHQ checked Sep 20, 202611-502 contacts →

Indirect evidence

“GeoX's leadership team consists of re-purposed oil and gas engineers, geophysicists, turbine engineers, thermodynamics Ph.D.'s, and operations leaders/entrepreneurs.”

Source: RevenueBase Database · checked Sep 20, 2026
25Strong evidenceSugar Land, TX, United StatesHQ checked Sep 20, 202611-502 contacts →

Strong evidence

“A Renewable E&P Power Company- We are a full cycle E&P geothermal power producer providing sustainable geothermal energy via the successful deployment of geothermal power plants…”

Source: RevenueBase Database · checked Sep 20, 2026

Showing 25 of 60 geothermal power plant operators based in the United States

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Geothermal power plant operators based in the United States at a glance

As of Sep 20, 2026
38.2%Verified-email coverage
146.4Average contacts per company
11-50Median size (employees)
18.3%Largest-city concentration · Houston
Sep 20, 2026Page data refreshed

Companies by employee count

1-10
29
11-50
23
51-200
3
201-500
1
1,001-5,000
2
5,001-10,000
1
10001+
1

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 60 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 power plant operators, 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 power plant operators”. 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 power plant operators), 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 power plant operators, 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, 3,353 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.

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 power plant operators, 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 power plant operators are there based in the United States?

RevenueBase identified 60 geothermal power plant operators 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?

Fieldcore, headquartered in Atlanta, tops this list with the largest team on record.

Which city has the most geothermal power plant operators?

Houston leads with 11 headquartered companies, followed by Reno (4) and Palo Alto (3).

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 3,353 verified decision-maker contacts tracked across these 60 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.