RecertifyReuseRepurpose

Electricity where the grid stops

We build industrial energy storage from certified second-life EV batteries. Keep the electricity you generate, use it when it is worth most, and know exactly what every kWh costs you.

LaureateLa French Tech
Jury’s favouriteEDF Pulse 2024
2nd prizeEVER Monaco 2025
FinalistCleantech Open France 2025

40–200kWModular power

1,000kWhMaximum storage

300kWpMaximum solar input

The future of storage is here

The Battery-Shelter

Made with certified second-life batteries, this system is perfect for optimizing your energy needs. Each battery undergoes rigorous testing, certification and optimization before integration, lowering CO₂ emissions and giving valuable storage materials a second working life.

Simple. Smart. Profitable.

Open Marny Battery-Shelter in the Lyon workshop: battery racks, inverters and cabling inside — 10-ft modular container SOFAR inverters · second-life cells

Solutions

Two form factors. One certified second-life battery platform.

Up to 360 kWh · 100 kVA

Mobile

Power, wherever you need it.

Flexibility and resilience: rapid, on-demand energy to underserved locations, events and emergency situations. A plug-and-play format that deploys in minutes: no fuel, no emissions, no noise.

Construction sitesOutdoor eventsEmergency responseEV chargingRemote worksites

Explore mobile →

Marny mobile energy unit in a white Renault Master van with the side door open, charging at a TotalEnergies DC fast-charging station — Mobile Utility-vehicle integration

Up to 1,000 kWh

Stationary

Store energy. Unlock value.

Stationary renewable-energy storage container for industrial applications, with the lowest carbon emissions, thanks to second-life batteries. Built inside a compact, modular 10-foot container: 40–200 kW of power, 120–1,000 kWh of storage, solar installations up to 300 kWp.

Industrial facilitiesCommercial buildingsEV chargingMicrogridsBackup power

Explore stationary →

On & Off-Grid

Modular solution with customized capacity, engineered around your site.

40–200kW

Power · from 40 kW

1,000kWh

Storage · from 120 kWh

300kWp

Solar installations · up to 300 kWp

Instead of sending excess electricity to the grid at uncertain (sometimes negative) rates, store it. Use it when demand is highest, or inject it back when market conditions are favorable.

With our customized solution you are free: you control how much each kWh will cost, and you own 100% of the electricity generated by you.

Our Experts

The people behind Marny Energy: engineering and business, based in Lyon.

President

Marc Areny

EV-battery expert.

CEO

Pierre-Antoine Preynat

Management and business development.

Optimize your investment

Understand how an energy storage solution can improve your results. Same site, two ways to build it. The payback speaks for itself.

Solar + Grid · baseline

10 yrs

Investment: 1.2M€
Annual savings: 120,000€
Return on investment: 10 years

Solar + Storage · with Battery-Shelter

6 yrs

Investment: 2M€
Annual savings: 300,000€
Return on investment: 6 years

Bonus: our solution reduces 400 tons of CO₂. Cheaper, smarter, predictable and green.

News

What we publish, what the press writes about us, and what we film on site.

Article 11 August 2026

Storing energy at a solar park: what the numbers actually say

A solar park without storage has to sell or use its power the moment it's produced. Add a Battery-Shelter and the same panels can shift that power to when it's worth more. We modelled what that changes.

Read article →

Article 1 August 2026

When selling your solar costs you money

Negative prices are no longer an anomaly on the European market. If your array exports at the wrong hour, you can pay to give your own electricity away.

Read article →

Article 28 July 2026