Energiestro

What Energiestro does

Energiestro is a French private technology company founded in 2001 by Anne and André Gennesseaux and headquartered in Châteaudun/Essert, France. The company develops the VOSS (Volant d'Options de Stockage Solaire) flywheel energy storage system, a kinetic storage device whose rotor is fabricated from prestressed concrete rather than from the carbon fiber or high-tensile steel used in conventional flywheels. The architecture combines this concrete rotor with a patented vacuum-chamber bearing solution using simple ball bearings assisted by a passive magnetic thrust bearing, eliminating the need for expensive active magnetic bearings, and a motor/alternator with an electronic converter that converts DC into high-frequency AC. Per company disclosure, the resulting system is roughly 10x cheaper than existing flywheel models, rated for more than 30 years and one million cycles, and stores approximately 10 kWh per cubic meter of concrete. A referenced IVL report (N°243, 2017) attributes the lowest cradle-to-gate carbon emissions to the concrete flywheel among the storage technologies evaluated.

Energiestro is incorporated as an SAS with €392,992 in share capital and operates with 1–10 employees. Its primary product is a 1.7 m diameter, 2.5 m tall, 10-ton, ~12 kWh / 7.5 kW VOSS unit. The company generates revenue (where any is generated) through two streams: direct hardware sales of VOSS units and, potentially, licensing of its patented technology. The go-to-market is direct enterprise sales into utilities, renewable-energy developers, and remote-site operators, supported by pilots with Voltalia (Guyana, ~10 kW / 10 kWh) and Engie (frequency-regulation pilot at the Thémis experimental center in Pyrénées-Orientales). Target applications include 24-hour solar time-shifting, smoothing of intermittent renewables, grid frequency regulation, and rural electrification.

The company has been funded almost entirely through non-dilutive public sources: the French Innovation 2030 Contest (€200,000 grant for VOSS, 2014), the EDF PULSE Contest 2015, the EU Horizon 2020 programme (grant agreement N°718125), a 2016 EISMEA grant, and the Shell LiveWIRE France program (2018, Top Ten Innovators 2019). It is supported by BPI France and the regional governments of Bourgogne-Franche-Comté and Centre-Val de Loire. No institutional venture capital, private equity, M&A, or public-market activity is disclosed.

Name

Energiestro

Legal name

ENERGIESTRO

Website

https://energiestro.net

Company type

Private

Founded year

2001

Operating status

Operating

Headcount range

11–50 employees

Short description

Energiestro is a French private technology company that develops the VOSS flywheel energy storage system, a prestressed-concrete kinetic-storage device positioned as a cheaper, longer-lived alternative to batteries and carbon-fiber flywheels. It targets utilities, renewable-energy developers, and remote-site operators.

Ownership category

akta.pro rank

Product category

Flywheel Energy Storage Systems

NAICS

Turbine and Turbine Generator Set Units Manufacturing (333611)

SIC

Motors & Generators (3621), Engines & Turbines (3510)

akta.pro primary industry

Mechanical LDES (Pumped Hydro, Compressed/Liquid Air, Flywheels) (EUAFADAB)

akta.pro secondary industries

LDES Systems Integration, EPC & Project Development (EUAFADAG), Energy Storage Balance-of-Plant (enclosures, switchgear, protection, metering) (IMAGAHAK)

Keywords

• Flywheel energy storage
• Kinetic energy storage
• Solar energy storage
• Grid frequency regulation
• Concrete flywheel systems

Headquarters

HQ city

Essert

HQ country

France

HQ region

Europe

Offices2 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Supply Chain, Operations, Technology or R&D, Personnel, Marketing or Sales, Infrastructure

Revenue model

1. Flywheel Energy Storage Systems: Energiestro generates revenue through the sale of their VOSS (Volant d'Optique à Structure Soufflante) flywheel energy storage systems. These are sold to utilities, energy companies, and project developers for applications including grid frequency regulation, renewable energy storage, and remote site power supply.
2. Technology Licensing: Energiestro protects its technology through international patents and may generate licensing revenue from their proprietary concrete flywheel technology.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels6 records

Core offering

Energiestro develops and manufactures the VOSS (Volant d'Options de Stockage Solaire) flywheel energy storage system, a kinetic energy storage device made from prestressed concrete. The system (12 kWh capacity, 1.7 m diameter, 2.5 m height, 10 ton mass, 7.5 kW output) is sold to utilities, energy companies, and project developers for solar energy time-shifting, grid frequency regulation, smoothing of intermittent renewables, and remote-site power supply. Energiestro also protects its IP through international patents and may license its technology.

Product overview

Energiestro offers a single core product line: the VOSS (Volant d'Options de Stockage Solaire / Solar Storage Wheel) flywheel system. This concrete flywheel energy storage solution is designed to reduce the cost of energy storage by a factor of ten compared to traditional battery technology. The VOSS stores kinetic energy mechanically, operates for over 30 years with unlimited cycles, and targets applications including solar energy time-shifting, grid frequency regulation, smoothing of intermittent renewables, and power supply to remote sites. The company has developed prototypes using both prestressed concrete and glass fiber composites with high-tension vertical filament winding.

Differentiator

Problem solved

Functional benefit

Brands

• VOSS: VOSS (Volant d'Optimum Solaire Stockage) is the company's flagship flywheel technology for solar energy storage, made of prestressed concrete to reduce costs compared to traditional steel or carbon fiber flywheels.

Products and services

• VOSS Flywheel (Volant d'Options de Stockage Solaire) Concrete flywheel energy storage system that stores kinetic energy using prestressed concrete cylinders, designed to store solar energy during the day for release at night. Delivers 12 kWh capacity with a 1.7 m diameter, 2.5 m height, 10 ton mass, and 7.5 kW power output, and operates for over 30 years and 1 million cycles. Sold to utilities, energy companies, and project developers for solar time-shifting, grid frequency regulation, smoothing of intermittent renewables, and remote-site power supply.

Quantifiable outcome

• Cost reduction of 10x compared to typical existing flywheel models
• +3 more outcomes

Named customers3 records

Segments4 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Partnerships

Three partnerships are on record, tiered core and supporting.

• EngiecoreStrategic or Co-development Partner · 1 April 2020Engie launched a project with Energiestro for frequency regulation at the Thémis experimental center in Pyrénées-Orientales. This represents the second order for Energiestro's flywheel equipment, following the Voltalia partnership.
• VoltaliacoreStrategic or Co-development Partner · 20 May 2019Energiestro signed a partnership with Voltalia to test their new VOSS technology. The partnership involves supplying equipment close to 10 kW / 10 kWh for a project in Guyana. This represents the first commercial deployment of the VOSS flywheel technology.
• Shell LiveWIREsupportingGTM or Marketing PartnerEnergiestro was selected for Shell LiveWIRE France program (2018) and later won Shell LiveWIRE Top Ten Innovators (2019), gaining visibility and support for startup development in energy and mobility.

Scale indicators7 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• Amber Kinetics: US-based developer of grid-scale kinetic flywheel energy storage systems targeting frequency regulation and renewable integration. Closely comparable to Energiestro as a flywheel-only energy storage vendor selling into utility customers.
• Beacon Power: Pioneer of grid-scale flywheel energy storage with operational 20 MW frequency regulation plants in the US. Direct flywheel peer with similar utility-facing, frequency-regulation value proposition to Energiestro's VOSS.
• Temporal Power: Canadian flywheel energy storage company focused on grid-scale applications. Comparable to Energiestro as a competing mechanical kinetic storage developer serving utility and renewable integration use cases.
• Vycon (VYCON / CalNetix): Manufacturer of flywheel-based uninterruptible power supply and energy storage systems for grid and mission-critical applications. Directly comparable flywheel technology targeting similar backup and grid-storage use cases.

Regional players

• S4 Energy: Dutch developer of kinetic energy storage using flywheel technology for Dutch and European grid markets. Closely comparable flywheel-based LDES approach with similar European utility customer base to Energiestro.

Emerging players

• Oxto Energy: UK-based developer of flywheel energy storage technology targeting grid and industrial applications. Comparable emerging mechanical-storage peer with overlapping renewable-integration and frequency-regulation use cases.
• Energy Vault: Swiss-American LDES company using gravity-based (solid-mass) storage to address the same utility-scale, long-duration, renewable-integration use cases as Energiestro. Closely comparable value proposition for non-lithium LDES at grid scale.

Broad incumbents

• Fluence Energy: Global grid-scale energy storage systems integrator (battery-based) serving the same utility customers and renewable-integration RFPs Energiestro targets. Broader incumbent with overlapping customer base but battery, not flywheel, technology.
• Saft (TotalEnergies): French industrial battery and energy storage manufacturer owned by TotalEnergies, serving utility, microgrid, and frequency-regulation markets. Comparable as a French-headquartered storage vendor selling into the same EDF/Engie-style customers Energiestro targets.
• Engie (Storage Business): Major French multinational utility and direct customer of Energiestro (Thémis frequency regulation pilot). Comparable as both an incumbent storage solutions buyer and a potential competitor/partner with broader portfolio of storage offerings.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat3 records

Key risks6 records

Key highlights6 records

Customer concentration

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Revenue estimate

Valuation estimate

Number of profiles

Profiles2 records

Funding overview

Funding rounds1 record

Investors1 record

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Energiestro