Company lists · Data refreshed September 2026
Top 25 Geothermal system designers worldwide
RevenueBase identified 4,408 geothermal system designers worldwide as of September 2026 and tracks 26,880 professional contacts across them, including 7,542 with verified work emails. The United States is the largest market and Madrid the largest hub.
This list covers geothermal system designers worldwide, 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 19, 2026. Country and city lists for geothermal system designers follow the table.
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.
The 25 largest geothermal system designers worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 1,281 contacts → | ||||
Indirect evidence “With over five decades of experience, Ormat Technologies, Inc.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 2 | 850 contacts → | ||||
Indirect evidence “We're leading the energy transition to zero carbon, by offering complete residential and commercial heating and hot water solutions.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 3 | 418 contacts → | ||||
Partial evidence “Comfort, designed around you – Since 1955, Ferroli has been a trusted name in HVAC, delivering innovative solutions for heating, cooling and hot water that combine comfort, energy…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 4 | 231 contacts → | ||||
Indirect evidence “Since 1978, Reliable Heating & Air has been serving all of Metro Atlanta's communities offering heating, cooling, plumbing and electrical services, indoor air quality, duct…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 5 | 224 contacts → | ||||
Indirect evidence “WaterFurnace International, Inc.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 6 | 220 contacts → | ||||
Indirect evidence “Tolin Mechanical is a Leading Energy & Commercial HVAC Services Company.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 7 | 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 19, 2026Thanks. The Data Team will review it. | |||||
| 8 | 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 19, 2026Thanks. The Data Team will review it. | |||||
| 9 | 149 contacts → | ||||
Indirect evidence “Eteck levert duurzame energie in de vorm van koude en warmte.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 10 | 132 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 11 | 128 contacts → | ||||
Partial evidence “ABOUT http://iceland-drilling.com/ Iceland Drilling Ltd is a leading high technical company in the field of high temperature geothermal drilling and has many decades of experience…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 12 | 124 contacts → | ||||
Indirect evidence “Bilgi birikimini yatırıma ve tasarrufa dönüştürmek için çalışmalarını 1990 yılından bu yana sürdüren Doğan Jeotermal Group ülkemizin sahip olduğu jeotermal enerji kaynaklarını…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 13 | 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 19, 2026Thanks. The Data Team will review it. | |||||
| 14 | 110 contacts → | ||||
Indirect evidence “At ENCON, we take care of people.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 15 | 108 contacts → | ||||
Indirect evidence “Brightcore Energy is a leading renewable energy solutions provider serving commercial, institutional, and government clients.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 16 | 105 contacts → | ||||
Indirect evidence “SYCHEM S.A.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 17 | 89 contacts → | ||||
Indirect evidence “Fondée en 1983 par Patrice Bobion (artisan électricien) et Jean-Pierre Joanin (artisan plombier) l’entreprise Bobion & Joanin est devenue en près de 40 ans un acteur majeur du…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 18 | 89 contacts → | ||||
Indirect evidence “CASA Mechanical is owned and operated by the W.G.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 19 | 87 contacts → | ||||
Partial evidence “Vaillant Österreich bietet #energiesparende und #umweltschonende Systeme für #Heizen,#Kühlen und #Warmwasser.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 20 | 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 19, 2026Thanks. The Data Team will review it. | |||||
| 21 | 81 contacts → | ||||
Partial evidence “Enertech Global is a leading manufacturer and visionary in the geothermal heating and cooling industry.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 22 | 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 19, 2026Thanks. The Data Team will review it. | |||||
| 23 | 79 contacts → | ||||
Indirect evidence “The Earth can accumulate summer heat and reuse it in the winter, so energy can be stored from season to season.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 24 | 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 19, 2026Thanks. The Data Team will review it. | |||||
| 25 | 69 contacts → | ||||
Partial evidence “Energy Machines is a leading provider of integrated energy systems that decarbonize heating and cooling while reducing operating costs for real estate owners, municipalities, and…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
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 designers. 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 designers.
- Partial evidence
- Its own public description names part of geothermal system designers, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name geothermal system designers. 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 4,408 geothermal system designers worldwide
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Geothermal system designers worldwide at a glance
As of Sep 19, 2026Companies by employee count
Email recency is reported on each country list linked below.
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 designers, 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.
- Coverage
- Every country. Country and city lists for geothermal system designers are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “geothermal system designers”. 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 designers), 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 designers, and records with no verified work email.
- 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, 7,542 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 19, 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 designers by location
17 lists · largest firstEvery Geothermal system designers list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
- Geothermal system designers based in the United States816
- Geothermal system designers based in France449
- Geothermal system designers based in Germany377
- Geothermal system designers based in Italy321
- Geothermal system designers based in the United Kingdom277
- Geothermal system designers based in Spain218
- Geothermal system designers based in the Netherlands213
- Geothermal system designers based in Canada170
- Geothermal system designers based in Belgium119
- Geothermal system designers based in Switzerland114
- Geothermal system designers based in Poland96
- Geothermal system designers based in Australia60
- Geothermal system designers based in Austria47
- Geothermal system designers based in Finland42
- Geothermal system designers based in Portugal38
- Geothermal system designers based in Sweden33
- Geothermal system designers based in Ireland28
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 designers, 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 designers are there worldwide?
RevenueBase identified 4,408 geothermal system designers worldwide 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?
Ormat Technologies, INC, headquartered in Reno, tops this list with the largest team on record.
Which country has the most geothermal system designers?
The United States leads with 816 companies, followed by France (449) and Germany (377). Every geothermal system designers list by country and city is linked on this page.
Which city has the most geothermal system designers?
Madrid leads with 23 headquartered companies, followed by London (21) and Roma (19).
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 7,542 verified decision-maker contacts tracked across these 4,408 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 19, 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.