Company lists · Data refreshed September 2026

Top 25 Geothermal energy investment firms based in the United States

RevenueBase identified 485 geothermal energy investment firms headquartered in the United States as of September 2026 and tracks 9,413 professional contacts across them, including 4,635 with verified work emails. Houston is the largest hub.

This list covers geothermal energy investment firms 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 28, 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 28, 2026 86% judged on-target in blind review
485Companies
9,413Contacts tracked
4,635Verified emails
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The 25 largest geothermal energy investment firms based in the United States

Ranked by team size
Top 25 of 485 geothermal energy investment firms based in the United States, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to geothermal energy investment firms: 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 evidenceHouston, TX, United StatesHQ checked Sep 28, 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 28, 2026
2Indirect evidenceReno, NV, United StatesHQ checked Sep 28, 20261,001-5,0001,281 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 28, 2026
3Indirect evidenceMiami, FL, United StatesHQ checked Sep 28, 2026201-500428 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 28, 2026
4Partial evidenceValhalla, NY, United StatesHQ checked Sep 28, 2026201-500304 contacts →

Partial evidence

“Who We Are Con Edison Development develops, owns and operates renewable and energy infrastructure projects.”

Source: RevenueBase Database · checked Sep 28, 2026
5Strong evidenceHouston, CA, United StatesHQ checked Sep 28, 202651-200213 contacts →

Strong evidence

“Fervo Energy provides 24/7 carbon-free energy through the development of next-generation geothermal power.”

Source: RevenueBase Database · checked Sep 28, 2026
6Partial evidenceBoston, MA, United StatesHQ checked Sep 28, 202651-200210 contacts →

Partial evidence

“Founded in 2016, Longroad Energy is a U.S-based energy company focused on developing and operating wind, solar, storage, and data center projects throughout North America.”

Source: RevenueBase Database · checked Sep 28, 2026
7Partial evidenceAnnapolis, MD, United StatesHQ checked Sep 28, 202651-200196 contacts →

Partial evidence

“HASI invests in sustainable infrastructure assets advancing the energy transition.”

Source: RevenueBase Database · checked Sep 28, 2026
8Strong evidenceNew York, NY, United StatesHQ checked Sep 28, 202651-200141 contacts →

Strong evidence

“As a multi-strategy investment manager and independent power producer, Greenbacker Renewable Energy Company (Greenbacker) is empowering a sustainable world by connecting…”

Source: RevenueBase Database · checked Sep 28, 2026
9Partial evidenceSummit, NJ, United StatesHQ checked Sep 28, 202651-200123 contacts →

Partial evidence

“ECP (Energy Capital Partners) is an investor in critical infrastructure focused on electrification, decarbonization, reliability and sustainability.”

Source: RevenueBase Database · checked Sep 28, 2026
10Strong evidenceMount Kisco, NY, United StatesHQ checked Sep 28, 202651-200118 contacts →

Strong 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 28, 2026
11Partial evidenceArmonk, NY, United StatesHQ checked Sep 28, 202651-200108 contacts →

Partial evidence

“Brightcore Energy is a leading renewable energy solutions provider serving commercial, institutional, and government clients.”

Source: RevenueBase Database · checked Sep 28, 2026
12Indirect evidenceNew York, NY, United StatesHQ checked Sep 28, 202651-200106 contacts →

Indirect evidence

“Speed and efficiency are the cornerstones of climate finance.”

Source: RevenueBase Database · checked Sep 28, 2026
13Strong evidenceGreenville, IL, United StatesHQ checked Sep 28, 202651-20081 contacts →

Strong evidence

“Enertech Global is a leading manufacturer and visionary in the geothermal heating and cooling industry.”

Source: RevenueBase Database · checked Sep 28, 2026
14Strong evidenceSalt Lake City, UT, United StatesHQ checked Sep 28, 202651-20069 contacts →

Strong 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 28, 2026
15Partial evidenceHouston, MA, United StatesHQ checked Sep 28, 202651-20062 contacts →

Partial evidence

“Quaise develops superhot geothermal power plants for a terawatt-scale world.”

Source: RevenueBase Database · checked Sep 28, 2026
16Partial evidenceWestport, CT, United StatesHQ checked Sep 28, 202611-5059 contacts →

Partial evidence

“True Green Capital Management LLC (“TGC”) is a specialized renewable energy infrastructure fund manager with a focus in distributed power generation in the US and Europe.”

Source: RevenueBase Database · checked Sep 28, 2026
17Partial evidenceDallas, TX, United StatesHQ checked Sep 28, 202651-20055 contacts →

Partial evidence

“Panda Power Funds was formed in 2010 by the former senior management team and energy professionals of Panda Energy International, an independent power development and management…”

Source: RevenueBase Database · checked Sep 28, 2026
18Indirect evidenceHouston, TX, United StatesHQ checked Sep 28, 202611-5052 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 28, 2026
19Partial evidenceHouston, TX, United StatesHQ checked Sep 28, 202611-5049 contacts →

Partial evidence

“Founded in 1998, Lime Rock Partners is a creative, value-adding, and long-term investor of growth capital in global energy companies in the exploration & production, energy…”

Source: RevenueBase Database · checked Sep 28, 2026
20Strong evidenceUnited StatesHQ checked Sep 28, 202651-20046 contacts →

Strong evidence

“Founded in 2004, Denham Capital is a global Energy Transition investment firm, having raised more than $12 billion of capital across multiple sectors.”

Source: RevenueBase Database · checked Sep 28, 2026
21Partial evidenceNew Brighton, MN, United StatesHQ checked Sep 28, 202611-5038 contacts →

Partial evidence

“Darcy Solutions is on a mission to put Geothermal Everywhere.”

Source: RevenueBase Database · checked Sep 28, 2026
22Partial evidenceHouston, TX, United StatesHQ checked Sep 28, 2026n/a37 contacts →

Partial evidence

“GEC invests in innovative energy technology and software companies.”

Source: RevenueBase Database · checked Sep 28, 2026
23Strong evidenceHouston, TX, United StatesHQ checked Sep 28, 202611-5036 contacts →

Strong evidence

“Renewa is a renewables company focused on acquisitions and investments within the solar, wind and renewable energy industries.”

Source: RevenueBase Database · checked Sep 28, 2026
24Strong evidenceStamford, CT, United StatesHQ checked Sep 28, 202611-5036 contacts →

Strong evidence

“We are a private investment firm dedicated exclusively to building businesses that help transform the world’s energy infrastructure.”

Source: RevenueBase Database · checked Sep 28, 2026
25Indirect evidenceSacramento, CA, United StatesHQ checked Sep 28, 202651-20035 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 28, 2026

Showing 25 of 485 geothermal energy investment firms based in the United States

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Geothermal energy investment firms based in the United States at a glance

As of Sep 28, 2026
49.2%Verified-email coverage
19.4Average contacts per company
1-10Median size (employees)
9.7%Largest-city concentration · Houston
Sep 28, 2026Page data refreshed

Companies by employee count

1-10
276
11-50
165
51-200
34
201-500
6
501-1,000
1
1,001-5,000
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 485 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 energy investment firms, 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 energy investment firms”. 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 energy investment firms), 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 energy investment firms, 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, 4,635 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 28, 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 energy investment firms, 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 energy investment firms are there based in the United States?

RevenueBase identified 485 geothermal energy investment firms 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 energy investment firms?

Houston leads with 47 headquartered companies, followed by New York (34) and Dallas (17).

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 4,635 verified decision-maker contacts tracked across these 485 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 28, 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.