# Energy companies headquartered in the Isère department
Tamtam tracks 41 energy companies headquartered in the Isère department. This list ranks the 30 largest by number of employees on LinkedIn, led by Verkor, Cegelec CEM and GEG - Gaz Electricité de Grenoble. Their median headcount is 72. Half of them were founded in 2010 or later. The most common headquarters are Grenoble (13).
The companies in Isère's energy sector encompass a range of activities, from established utilities to emerging renewable energy and nuclear fusion developers. Most are mid-sized to large companies, with a notable presence of younger firms. Verkor, founded in 2020, produces low-carbon batteries, while GEG - Gaz Electricité de Grenoble, established in 1867, focuses on renewable energy production and distribution. Waga Energy converts landfill gas into renewable natural gas, and Renaissance Fusion is developing stellarator-based nuclear fusion technology.
The data reveals a concentration of companies in Grenoble and its immediate surroundings. Many of these firms specialize in renewable energy generation, such as Helexia Agri, which builds agricultural hangars with solar panels, and INOCEL, designing high-power fuel cells. This suggests a regional focus on sustainable energy solutions and advanced energy technologies.
🇫🇷 Isère · 30 companies · Updated Nov 11, 2026
| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Verkor](https://www.tamtam.ai/c/verkor) (verkor.com)
Produces low-carbon batteries in France and Europe for electric vehicles and stationary storage, with a Gigafactory operational by 2025. | Motor Vehicle Parts Manufacturing | 🇫🇷 Grenoble | 997 | 2020 |
| 2 | [Cegelec CEM](https://www.tamtam.ai/c/cegelec-cem) (cegelec-cem.fr)
Designs, builds, and integrates equipment for new nuclear constructions, renovations, decommissioning, and high-stakes mechanical and electromechanical engineering projects in nuclear environments. | Industrial Machinery Manufacturing | 🇫🇷 Grenoble | 770 | |
| 3 | [GEG - Gaz Electricité de Grenoble](https://www.tamtam.ai/c/geg-gaz-electricite-de-grenoble) (groupe.geg.fr)
Energy production, distribution, and supply with focus on renewable sources, sustainability, and community engagement across France. | Renewable Energy Power Generation | 🇫🇷 Grenoble | 386 | 1867 |
| 4 | [MasterGrid](https://www.tamtam.ai/c/mastergrid) (mastergrid.com)
MasterGrid specializes in electrical system services from high to low voltage, providing tailored solutions to optimize system lifecycle and improve environmental impact | Electric Power Transmission, Control, and Distribution | 🇫🇷 Grenoble | 328 | 2019 |
| 5 | [Waga Energy](https://www.tamtam.ai/c/waga-energy) (waga-energy.com)
This company converts landfill gas into Renewable Natural Gas (RNG) using patented technology, reducing CO2 emissions and supplying households with biomethane | Renewable Energy Power Generation | 🇫🇷 Eybens | 316 | 2015 |
| 6 | [Compagnie de Chauffage](https://www.tamtam.ai/c/compagnie-de-chauffage) (compagniedechauffage.fr)
Management and operation of an extensive urban heat network supplying over 100,000 homes with 82% renewable and recovered energy. | Environmental Services | 🇫🇷 Grenoble | 138 | 1960 |
| 7 | [Depagne](https://www.tamtam.ai/c/depagne) (depagne.fr)
Since 1920, the company specializes in manufacturing low voltage electrical connection, protection, and distribution equipment for public distribution networks | Appliances, Electrical, and Electronics Manufacturing | 🇫🇷 Meylan | 116 | 1920 |
| 8 | [Helexia Agri](https://www.tamtam.ai/c/helexia-agri) (helexia-agri.com)
Building agricultural hangars with solar panels, operating them for farmers. This develops farming activity and generates green energy. | Renewable Energy Power Generation | 🇫🇷 Villefontaine | 114 | 2006 |
| 9 | [STEDIS](https://www.tamtam.ai/c/stedis) (stedis.com)
STEDIS is a Saint-Martin-d'Hères based company specializing in fuel and AdBlue distribution, connected devices, and energy savings certificates | Oil and Gas | 🇫🇷 Saint-Martin-d'Hères | 111 | |
| 10 | [Renaissance Fusion](https://www.tamtam.ai/c/renaissance-fusion) (renfusion.eu)
Development of stellarator-based nuclear fusion technology aiming to simplify fusion processes, reduce electricity costs, and expand high temperature superconductor availability. | Nuclear Electric Power Generation | 🇫🇷 Grenoble | 104 | 2020 |
| 11 | [EDF ENR PWT (Photowatt)](https://www.tamtam.ai/c/edf-enr-pwt-photowatt) (photowatt.com)
Design and manufacture of photovoltaic wafers, cells, and modules with advanced technology and strict quality control in France. | Renewable Energy Semiconductor Manufacturing | 🇫🇷 Bourgoin-Jallieu | 96 | 1979 |
| 12 | [GreenAlp](https://www.tamtam.ai/c/greenalp) (greenalp.fr)
For the past 150 years, this company has been distributing gas and electricity in Grenoble, focusing on technical expertise, customer culture, innovation, and future energy models | Utilities | 🇫🇷 Grenoble | 85 | 2019 |
| 13 | [SDMS la chaudronnerie blanche](https://www.tamtam.ai/c/sdms-la-chaudronnerie-blanche) (sdms.fr)
Manufacture of specialized equipment and assemblies from noble metals for energy, nuclear, and advanced research applications with strict quality standards. | Industrial Machinery Manufacturing | 🇫🇷 Saint-Romans | 78 | 1962 |
| 14 | [Hydrogen Refueling Solutions - HRS](https://www.tamtam.ai/c/hydrogen-refueling-solutions-hrs) (hydrogen-refueling-solutions.fr)
Design manufacture install and maintain hydrogen refueling stations and industrial piping, supporting decarbonization of transport and industrial sectors in Europe. | Renewables & Environment | 🇫🇷 Champagnier | 78 | 2004 |
| 15 | [INOCEL](https://www.tamtam.ai/c/inocel) (inocel.com)
A French company that designs, manufactures, and markets high power fuel cells for stationary, heavy ground mobility, and marine sectors with expertise in system integration and maintenance services | Renewable Energy Power Generation | 🇫🇷 Grenoble | 72 | 2021 |
| 16 | [SDCEM](https://www.tamtam.ai/c/sdcem) (sdcem.com)
The company specializes in designing and manufacturing switching solutions for Medium, High, and Very High Voltage applications, with a focus on safety, reliability, and efficiency | Appliances, Electrical, and Electronics Manufacturing | 🇫🇷 Champagnier | 68 | 1947 |
| 17 | [EOLYA](https://www.tamtam.ai/c/eolya) (eolya.com)
Provides energy and environmental efficiency services with guaranteed results for public, commercial, residential, and industrial clients in Auvergne-Rhône-Alpes region. | Facilities Services | 🇫🇷 Saint-Martin-le-Vinoux | 63 | 2000 |
| 18 | [Limatech](https://www.tamtam.ai/c/limatech-voreppe) (limatech.energy)
Design and manufacture of certified 28V lithium batteries for aircraft providing weight savings, increased longevity, and improved availability over lead-acid and nickel-cadmium technologies. | Aviation and Aerospace Component Manufacturing | 🇫🇷 Voreppe | 43 | 2016 |
| 19 | [TETRADIS](https://www.tamtam.ai/c/tetradis) (tetradis.com)
French company specializing in smart energy solutions, connectivity, photovoltaic systems, and electric mobility with personalized technical support. | Telecommunications | 🇫🇷 Saint-Quentin-Fallavier | 43 | 2003 |
| 20 | [BeFC Bioenzymatic Fuel Cells](https://www.tamtam.ai/c/befc-bioenzymatic-fuel-cells) (befc.fr)
BeFC develops metal-free paper biofuel cells using enzymes to generate electricity for low-power electronics, enabling sustainable, wireless data transmission and sensing opportunities | Renewable Energy Semiconductor Manufacturing | 🇫🇷 Grenoble | 41 | 2020 |
| 21 | [Actemium Grenoble](https://www.tamtam.ai/c/actemium-grenoble) (actemium.fr)
Specializing in industrial process solutions, this company offers expertise in hydroelectricity, industrial processes, and gas processes, serving clients locally and globally | Automation Machinery Manufacturing | 🇫🇷 Seyssins | 37 | 1998 |
| 22 | [INOVALP](https://www.tamtam.ai/c/inovalp) (inovalp.fr)
An innovative industrial company in the renewable energy sector, specializing in designing and manufacturing wood pellet stoves and grills with a focus on eco-friendly solutions | Renewable Energy Semiconductor Manufacturing | 🇫🇷 Saint-Honoré | 36 | 2012 |
| 23 | [ECM Greentech](https://www.tamtam.ai/c/ecm-greentech)
An equipment design and manufacturing company with a focus on renewable energies, semiconductor, and crystal growing furnaces, offering turnkey factory solutions | Semiconductor Manufacturing | 🇫🇷 Grenoble | 31 | 1928 |
| 24 | [Mantle8](https://www.tamtam.ai/c/mantle8) (mantle8.com)
Specializes in discovering natural hydrogen reservoirs through geological expertise to support the global transition to clean energy sources. | Climate Technology Product Manufacturing | 🇫🇷 Grenoble | 26 | |
| 25 | [EREMA](https://www.tamtam.ai/c/erema) (erema.fr)
Specialists in micro hydroelectric power, covering study, implementation, and operation with expertise since 1989. | Renewable Energy Semiconductor Manufacturing | 🇫🇷 Herbeys | 26 | 1989 |
| 26 | [Caeli Energie](https://www.tamtam.ai/c/caeli-energie) (caeli-energie.com)
Design and manufacture of next-generation air conditioners focused on high energy efficiency and significantly reduced carbon footprint. | Appliances, Electrical, and Electronics Manufacturing | 🇫🇷 Grenoble | 24 | 2020 |
| 27 | [Domosolaris](https://www.tamtam.ai/c/domosolaris) (domosolaris.com)
With 10 years of expertise in energy autonomy, this company specializes in installing solar panels, heat pumps, and other renewable energy solutions for homes | Services for Renewable Energy | 🇫🇷 Villard-Bonnot | 24 | 2013 |
| 28 | [Enercoop Auvergne-Rhone-Alpes](https://www.tamtam.ai/c/enercoop-auvergne-rhone-alpes) (enercoop.fr)
Provider of 100% renewable and ethical electricity through a cooperative model, created by organizations promoting environmental and social solidarity | Electric Power Generation | 🇫🇷 Grenoble | 23 | 2010 |
| 29 | [WATTALPS](https://www.tamtam.ai/c/wattalps) (wattalps.com)
Designing and manufacturing patented immersion cooled lithium-ion batteries for heavy duty equipment, construction machinery, and high performance vehicles to improve safety and longevity. | Industrial Machinery Manufacturing | 🇫🇷 Moirans | 23 | 2018 |
| 30 | [Sylfen](https://www.tamtam.ai/c/sylfen) (sylfen.com)
Sylfen specializes in developing energy storage solutions using reversible high temperature systems to promote renewable and carbon-free energy transition | Electrical Equipment Manufacturing | 🇫🇷 Le Cheylas | 22 | 2015 |
## How this list is built
Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 11, 2026.
## More company lists in the Isère department
- [The largest companies in the Isère department](https://www.tamtam.ai/l/largest-companies-isere) (1,457)
- [Companies with in-house R&D in the Isère department](https://www.tamtam.ai/l/r-and-d-companies-isere) (304)
- [Manufacturers in the Isère department](https://www.tamtam.ai/l/manufacturers-isere) (178)
- [Multinational companies in the Isère department](https://www.tamtam.ai/l/multinational-companies-isere) (174)
- [Hardware manufacturers in the Isère department](https://www.tamtam.ai/l/hardware-companies-isere) (143)
- [Retail chains in the Isère department](https://www.tamtam.ai/l/retail-chains-isere) (100)
- [Software Development companies in the Isère department](https://www.tamtam.ai/l/software-development-companies-isere) (90)
- [Professional services firms in the Isère department](https://www.tamtam.ai/l/professional-services-firms-isere) (87)
- [Public sector organisations in the Isère department](https://www.tamtam.ai/l/public-sector-organisations-isere) (80)
- [Distributors and wholesalers in the Isère department](https://www.tamtam.ai/l/distributors-and-wholesalers-isere) (78)
- [IT services companies in the Isère department](https://www.tamtam.ai/l/it-services-companies-isere) (75)
- [SaaS companies in the Isère department](https://www.tamtam.ai/l/saas-companies-isere) (72)
- [Electronics and semiconductor companies in the Isère department](https://www.tamtam.ai/l/electronics-companies-isere) (70)
- [Contract manufacturers in the Isère department](https://www.tamtam.ai/l/contract-manufacturers-isere) (68)
- [IT Services and IT Consulting companies in the Isère department](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-isere) (68)
- [Family-owned companies in the Isère department](https://www.tamtam.ai/l/family-owned-companies-isere) (61)
- [Industrial Machinery Manufacturing companies in the Isère department](https://www.tamtam.ai/l/industrial-machinery-manufacturing-companies-isere) (58)
- [Consulting firms in the Isère department](https://www.tamtam.ai/l/consulting-firms-isere) (57)
- [Construction companies in the Isère department](https://www.tamtam.ai/l/construction-companies-isere) (52)
- [Pharmaceutical companies in the Isère department](https://www.tamtam.ai/l/pharmaceutical-companies-isere) (47)
- [Education providers in the Isère department](https://www.tamtam.ai/l/education-companies-isere) (46)
- [Medical device companies in the Isère department](https://www.tamtam.ai/l/medical-device-companies-isere) (43)
- [Critical infrastructure operators in the Isère department](https://www.tamtam.ai/l/critical-infrastructure-operators-isere) (41)
- [Chemical companies in the Isère department](https://www.tamtam.ai/l/chemical-companies-isere) (40)
## The same list elsewhere in France
- [Energy companies in France](https://www.tamtam.ai/l/energy-companies-france) (1,594)
- [Energy companies in Île-de-France](https://www.tamtam.ai/l/energy-companies-ile-de-france) (475)
- [Energy companies in Auvergne-Rhône-Alpes](https://www.tamtam.ai/l/energy-companies-auvergne-rhone-alpes) (236)
- [Energy companies in Nouvelle-Aquitaine](https://www.tamtam.ai/l/energy-companies-nouvelle-aquitaine) (173)
- [Energy companies in the Hauts-de-Seine department](https://www.tamtam.ai/l/energy-companies-hauts-de-seine) (144)
- [Energy companies in Occitanie](https://www.tamtam.ai/l/energy-companies-occitanie) (128)
- [Energy companies in Provence-Alpes-Côte d'Azur](https://www.tamtam.ai/l/energy-companies-provence-alpes-cote-dazur) (124)
- [Energy companies in Grand Est](https://www.tamtam.ai/l/energy-companies-grand-est) (115)
- [Energy companies in the Rhône department](https://www.tamtam.ai/l/energy-companies-rhone) (104)
- [Energy companies in Hauts-de-France](https://www.tamtam.ai/l/energy-companies-hauts-de-france) (74)
- [Energy companies in Pays de la Loire](https://www.tamtam.ai/l/energy-companies-pays-de-la-loire) (66)
- [Energy companies in the Gironde department](https://www.tamtam.ai/l/energy-companies-gironde) (61)
- [Energy companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/energy-companies-bouches-du-rhone) (58)
- [Energy companies in Brittany](https://www.tamtam.ai/l/energy-companies-brittany) (56)
- [Energy companies in the Haute-Garonne department](https://www.tamtam.ai/l/energy-companies-haute-garonne) (48)
- [Energy companies in the Nord department](https://www.tamtam.ai/l/energy-companies-nord) (42)
- [Energy companies in the Loire-Atlantique department](https://www.tamtam.ai/l/energy-companies-loire-atlantique) (40)
- [Energy companies in Bourgogne-Franche-Comté](https://www.tamtam.ai/l/energy-companies-bourgogne-franche-comte) (38)
- [Energy companies in the Hérault department](https://www.tamtam.ai/l/energy-companies-herault) (38)
- [Energy companies in Normandy](https://www.tamtam.ai/l/energy-companies-normandy) (38)
- [Energy companies in the Bas-Rhin department](https://www.tamtam.ai/l/energy-companies-bas-rhin) (33)
- [Energy companies in Paris](https://www.tamtam.ai/l/energy-companies-paris) (187)
- [Energy companies in Lyon](https://www.tamtam.ai/l/energy-companies-lyon) (34)
- [Energy companies in Toulouse](https://www.tamtam.ai/l/energy-companies-toulouse) (33)
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Source: https://www.tamtam.ai/l/energy-companies-isere