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.
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 |
Verkorverkor.com
Produces low-carbon batteries in France and Europe for electric vehicles and stationary storage, with a Gigafactory operational by 2025. |
997 | |||
| 2 |
Cegelec CEMcegelec-cem.fr
Designs, builds, and integrates equipment for new nuclear constructions, renovations, decommissioning, and high-stakes mechanical and electromechanical engineering projects in nuclear environments. |
770 | |||
| 3 |
GEG - Gaz Electricité de Grenoblegroupe.geg.fr
Energy production, distribution, and supply with focus on renewable sources, sustainability, and community engagement across France. |
386 | |||
| 4 |
MasterGridmastergrid.com
MasterGrid specializes in electrical system services from high to low voltage, providing tailored solutions to optimize system lifecycle and improve environmental impact |
328 | |||
| 5 |
Waga Energywaga-energy.com
This company converts landfill gas into Renewable Natural Gas (RNG) using patented technology, reducing CO2 emissions and supplying households with biomethane |
316 | |||
| 6 |
Compagnie de Chauffagecompagniedechauffage.fr
Management and operation of an extensive urban heat network supplying over 100,000 homes with 82% renewable and recovered energy. |
138 | |||
| 7 |
Depagnedepagne.fr
Since 1920, the company specializes in manufacturing low voltage electrical connection, protection, and distribution equipment for public distribution networks |
116 | |||
| 8 |
Helexia Agrihelexia-agri.com
Building agricultural hangars with solar panels, operating them for farmers. This develops farming activity and generates green energy. |
114 | |||
| 9 |
STEDISstedis.com
STEDIS is a Saint-Martin-d'Hères based company specializing in fuel and AdBlue distribution, connected devices, and energy savings certificates |
111 | |||
| 10 |
Renaissance Fusionrenfusion.eu
Development of stellarator-based nuclear fusion technology aiming to simplify fusion processes, reduce electricity costs, and expand high temperature superconductor availability. |
104 | |||
| 11 |
EDF ENR PWT (Photowatt)photowatt.com
Design and manufacture of photovoltaic wafers, cells, and modules with advanced technology and strict quality control in France. |
96 | |||
| 12 |
GreenAlpgreenalp.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 |
85 | |||
| 13 |
SDMS la chaudronnerie blanchesdms.fr
Manufacture of specialized equipment and assemblies from noble metals for energy, nuclear, and advanced research applications with strict quality standards. |
78 | |||
| 14 |
Hydrogen Refueling Solutions - HRShydrogen-refueling-solutions.fr
Design manufacture install and maintain hydrogen refueling stations and industrial piping, supporting decarbonization of transport and industrial sectors in Europe. |
78 | |||
| 15 |
INOCELinocel.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 |
72 | |||
Want more companies than this list?This page shows the largest ones only. Connect to Tamtam to see every company that matches, filter by size, industry or growth, and reach their decision-makers. | |||||
| 16 | 68 | ||||
| 17 | 63 | ||||
| 18 |
Limatechlimatech.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. |
43 | |||
| 19 |
TETRADIStetradis.com
French company specializing in smart energy solutions, connectivity, photovoltaic systems, and electric mobility with personalized technical support. |
43 | |||
| 20 |
BeFC Bioenzymatic Fuel Cellsbefc.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 |
41 | |||
| 21 |
Actemium Grenobleactemium.fr
Specializing in industrial process solutions, this company offers expertise in hydroelectricity, industrial processes, and gas processes, serving clients locally and globally |
37 | |||
| 22 |
INOVALPinovalp.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 |
36 | |||
| 23 |
ECM Greentech
An equipment design and manufacturing company with a focus on renewable energies, semiconductor, and crystal growing furnaces, offering turnkey factory solutions |
31 | |||
| 24 |
Mantle8mantle8.com
Specializes in discovering natural hydrogen reservoirs through geological expertise to support the global transition to clean energy sources. |
26 | |||
| 25 | 26 | ||||
| 26 |
Caeli Energiecaeli-energie.com
Design and manufacture of next-generation air conditioners focused on high energy efficiency and significantly reduced carbon footprint. |
24 | |||
| 27 |
Domosolarisdomosolaris.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 |
24 | |||
| 28 |
Enercoop Auvergne-Rhone-Alpesenercoop.fr
Provider of 100% renewable and ethical electricity through a cooperative model, created by organizations promoting environmental and social solidarity |
23 | |||
| 29 |
WATTALPSwattalps.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. |
23 | |||
| 30 |
Sylfensylfen.com
Sylfen specializes in developing energy storage solutions using reversible high temperature systems to promote renewable and carbon-free energy transition |
22 | |||
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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 1,457
- Companies with in-house R&D in the Isère department 304
- Manufacturers in the Isère department 178
- Multinational companies in the Isère department 174
- Hardware manufacturers in the Isère department 143
- Retail chains in the Isère department 100
- Software Development companies in the Isère department 90
- Professional services firms in the Isère department 87
- Public sector organisations in the Isère department 80
- Distributors and wholesalers in the Isère department 78
- IT services companies in the Isère department 75
- SaaS companies in the Isère department 72
- Electronics and semiconductor companies in the Isère department 70
- Contract manufacturers in the Isère department 68
- IT Services and IT Consulting companies in the Isère department 68
- Family-owned companies in the Isère department 61
- Industrial Machinery Manufacturing companies in the Isère department 58
- Consulting firms in the Isère department 57
- Construction companies in the Isère department 52
- Pharmaceutical companies in the Isère department 47
- Education providers in the Isère department 46
- Medical device companies in the Isère department 43
- Critical infrastructure operators in the Isère department 41
- Chemical companies in the Isère department 40
The same list elsewhere in France
- Energy companies in France 1,594
- Energy companies in Île-de-France 475
- Energy companies in Auvergne-Rhône-Alpes 236
- Energy companies in Nouvelle-Aquitaine 173
- Energy companies in the Hauts-de-Seine department 144
- Energy companies in Occitanie 128
- Energy companies in Provence-Alpes-Côte d'Azur 124
- Energy companies in Grand Est 115
- Energy companies in the Rhône department 104
- Energy companies in Hauts-de-France 74
- Energy companies in Pays de la Loire 66
- Energy companies in the Gironde department 61
- Energy companies in the Bouches-du-Rhône department 58
- Energy companies in Brittany 56
- Energy companies in the Haute-Garonne department 48
- Energy companies in the Nord department 42
- Energy companies in the Loire-Atlantique department 40
- Energy companies in Bourgogne-Franche-Comté 38
- Energy companies in the Hérault department 38
- Energy companies in Normandy 38
- Energy companies in the Bas-Rhin department 33
- Energy companies in Paris 187
- Energy companies in Lyon 34
- Energy companies in Toulouse 33