The energy sector in Loire-Atlantique features a mix of established industrial players and younger companies focused on renewable energy. Chantiers de l'Atlantique, founded in 1861, is a marine construction company building complex ships. Sercel provides subsurface measurement solutions, while AS 24 specializes in fuel distribution for heavy goods vehicles. Lhyfe focuses on green industrial hydrogen production, and Vaillant Group France develops heating and cooling systems using renewable energy.
A notable pattern is the concentration of companies in Nantes, which serves as a hub for both traditional and emerging energy businesses. The area also shows a strong emphasis on renewable energy, with firms like Dome Solar manufacturing photovoltaic mounting systems, Beem offering solar solutions for homes, and Armor Battery Films enhancing lithium-ion battery performance.
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 |
Chantiers de l'Atlantiquechantiers-atlantique.com
Marine construction company, building complex ships and marine installations, including passenger ships and substations. Global leader in design, manufacturing, and commissioning of innovative, environmentally friendly vessels. |
2,472 | |||
| 2 |
Sercelsercel.com
Leading provider of high-standard subsurface measurement and data solutions for natural resources, infrastructure monitoring, energy transition, and defense sectors since 1956. |
942 | |||
| 3 | 380 | ||||
| 4 |
MADIC groupgroupe.madic.com
innovative French industrialist in electronic payment, petroleum equipment, services, and Digital Media communication, with a focus on sustainable development values. |
267 | |||
| 5 |
MADIC SASgroupe.madic.com
A French leader in payment and petrol equipment and services, providing customized solutions for gas stations, renovations, and compliance updates across France, Spain, and Belgium |
237 | |||
| 6 | 217 | ||||
| 7 |
Vaillant Group Francejobs.vaillant-group.com
Development and manufacturing of heating and cooling systems focused on renewable energy, providing comfort and customized solutions in France. |
205 | |||
| 8 |
Knutsen LNG Franceknutsenoas.com
A subsidiary of Knutsen OAS Shipping managing LNG carriers sailing under the RIF Flag with French officers from a French office |
165 | |||
| 9 |
Leroux & Lotz Technologies (LLT)lerouxlotz.com
Design and manufacture of custom biomass boilers and combustion systems, including maintenance, refurbishment, and complete rebuild services. |
149 | |||
| 10 |
Territoire d'énergie Loire-Atlantique (TE44)te44.fr
Manages public electricity and gas distribution networks, maintains street lighting, invests in renewable energy infrastructure, and operates electric vehicle charging stations. |
92 | |||
| 11 |
Dome Solardome-solar.com
French leader manufacturing high quality photovoltaic mounting systems for flat and sloped roofs across industrial, commercial, and agricultural sectors with certified technical assistance. |
73 | |||
| 12 |
Beembeemenergy.fr
Helping individuals take charge of their energy consumption and accelerate the transition to cleaner energy sources for homes |
70 | |||
| 13 |
SYSTOVIsystovi.com
Specializing in creating and producing cutting-edge BIPV systems that seamlessly integrate solar panels into building structures for energy generation |
54 | |||
| 14 |
Sunologysunology.eu
Provider of residential solar solutions including plug-and-play stations, smart custom roofs, modular batteries, and monitoring applications for home energy autonomy and savings. |
46 | |||
| 15 |
Armor Battery Filmsarmorbatteryfilms.com
Specializing in enhancing lithium-ion battery performance, En' Safe® provides aluminum/copper foil coated with a conductive primer to improve anode/cathode interface for increased safety and longevity |
42 | |||
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 |
DINTECgokinell.com
Family-owned company specializing in custom solutions for mobile machine manufacturers, combining expertise in electronics, hydraulics, and more to create innovative and high-quality projects |
42 | |||
| 17 |
ALKA MARINEalkamarine.com
A new player in renewable marine energy support, offering integrated solutions from design to maritime operations, owns a tugboat and a bathymetric vessel under the French flag |
40 | |||
| 18 |
GAROS ENERGIEgaros-energie.fr
Electrotechnical manufacturing company located in France specializing in energy solutions and electrical components |
39 | |||
| 19 |
GeniWattgeniwatt.fr
GeniWatt offers turnkey solutions for diesel and gas power plants, providing installation, commissioning, maintenance, and supply of certified replacement parts |
38 | |||
| 20 |
PHOTOVOLTphotovolt.fr
Photovolt specializes in designing and installing solar panels for residential and commercial clients, offering services from consultation to installation and maintenance |
38 | |||
| 21 |
Libre Energielibre-energie.com
Specializing in solar energy production since 2007, we aim to provide clean energy solutions for individuals and businesses with personalized and quality service |
37 | |||
| 22 |
hestiiago.hestiia.com
Innovative company leveraging wasted heat from computers to create sustainable consumer products, driving the energy transition towards a greener future |
26 | |||
| 23 |
Be Greenbegreen-group.fr
Design, manufacture, and install solar power plants, solar buildings, canopies, and charging stations with integrated expertise and comprehensive support. |
25 | |||
| 24 |
Enerdigitenerdigit.fr
Electricity flexibility operator providing financial compensation for load shedding and developing large-scale battery storage projects to ensure grid security and energy transition. |
24 | |||
| 25 |
GEPS Technogeps-techno.com
Harvest ocean data, enable offshore communication networks, power subsea equipment with marine renewable energies, develop customized innovative solutions. |
22 | |||
| 26 |
SYCOMOREkeon-group.com
Sycomore specializes in operating and maintaining agricultural and territorial biogas units, with a team of experienced multidisciplinary professionals #biomethane #biogas |
21 | |||
| 27 |
PNE Francepne-france.fr
Develops, builds, and operates wind and solar farms across metropolitan territory, integrating human and environmental stakes in renewable energy projects. |
20 | |||
| 28 |
Hellospark ⚡️hellospark.fr
French company specializing in renewable energy and electric mobility, transforming unused spaces into solar energy centers with photovoltaic canopies to reduce carbon footprint |
18 | |||
| 29 |
2G Energie France SAS2-g.com
Design and supply of turnkey biogas and natural gas cogeneration plants with patented engines, remote monitoring, and nationwide technical support in France. |
18 | |||
| 30 |
NEOS SOLAIRE - Orvaultneos-solaire.fr
NEOS specializes in tailored photovoltaic solutions for businesses, focusing on energy efficiency, financial optimization, and sustainability for a greener future |
18 | |||
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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 14, 2026.
More company lists in the Loire-Atlantique department
- The largest companies in the Loire-Atlantique department 2,044
- Companies with in-house R&D in the Loire-Atlantique department 207
- Retail chains in the Loire-Atlantique department 162
- Multinational companies in the Loire-Atlantique department 159
- Professional services firms in the Loire-Atlantique department 158
- Software Development companies in the Loire-Atlantique department 137
- SaaS companies in the Loire-Atlantique department 135
- IT services companies in the Loire-Atlantique department 130
- Manufacturers in the Loire-Atlantique department 125
- IT Services and IT Consulting companies in the Loire-Atlantique department 110
- Consulting firms in the Loire-Atlantique department 94
- Distributors and wholesalers in the Loire-Atlantique department 94
- Hardware manufacturers in the Loire-Atlantique department 86
- Business Consulting and Services companies in the Loire-Atlantique department 83
- Public sector organisations in the Loire-Atlantique department 80
- Family-owned companies in the Loire-Atlantique department 71
- Education providers in the Loire-Atlantique department 68
- Real Estate companies in the Loire-Atlantique department 67
- Financial services firms in the Loire-Atlantique department 65
- Law Practice companies in the Loire-Atlantique department 62
- Retail companies in the Loire-Atlantique department 61
- Subscription businesses in the Loire-Atlantique department 61
- Critical infrastructure operators in the Loire-Atlantique department 58
- Events Services companies in the Loire-Atlantique department 58
The same list elsewhere in France
- Energy companies in France 1,594
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- 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 116
- 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 Isère department 41
- Energy companies in the Hérault department 38
- Energy companies in Normandy 38
- Energy companies in Bourgogne-Franche-Comté 37
- Energy companies in the Bas-Rhin department 33
- Energy companies in Paris 187
- Energy companies in Lyon 34
- Energy companies in Toulouse 33