Symphonics takes a key step toward aFRR certification of low-voltage batteries under real-world operating conditions at Energies de Loire
Symphonics takes a key step toward aFRR certification of low-voltage batteries under real-world operating conditions at Energies de Loire
Symphonics, a company specializing in smart energy management, announces the success of a full-scale trial of its solution for managing automatic frequency restoration reserve (aFRR) using low-voltage (LV) batteries at a storage facility operated by Energies de Loire.
This campaign, conducted using test cases designed by the Symphonics teams based on the qualification requirements RTE, marks a new decisive step toward the qualification of low-voltage assets in the power system balancing market.
An end-to-end test under real-world conditions
The tests took place on April 29, 2026, at theEnergies de Loiresite in Candé, with a battery connected to the Symphonics control system via the Symphonics control box, which was physically wired to the site’s battery (Huawei LUNA).
The entire system was tested under operational conditions: reception of activation signals, dispatch calculations, equipment control, real-time telemetry feedback, system resilience, and observability. Several additional scenarios were simulated, including:
- a downward-sloping ramp (10 minutes), to test behavior under unidirectional loading;
- an asymmetrical load (17 minutes), to stress the chain's dynamics;
- a long-duration profile with a realistic activation signal (2 hours and 30 minutes), to verify robustness under continuous operation.
Results that exceed RTE requirements
The key criterion used byRTEto classify a facility as secondary reserve is the asset’s ability to remain within the tolerance corridor around the setpoint for at least 95% of the test duration.
Across all three profiles, the Symphonics solution achieved a compliance rate of over 99%, which is more than four percentage points above the required qualification threshold.
- The setpoint tracking accuracy is on the order of 200 W root mean square error over the long-term test, which demonstrates a very tight alignment between the theoretical setpoint and the actual power output.
- End-to-end latency—measured from the time the Symphonics platform receives the trigger signal to the time the drum kit sends back the execution confirmation—remained below 400 ms at the median and below 500 ms at the 95th percentile across the most representative profiles.
- Finally, the long-term test confirmed the system’s robustness over more than two and a half hours of continuous operation, with 2,229 commands sent and 2,229 acknowledgments received—a 100% reliability rate—without any signal loss.
These performance specifications meet the most stringent requirements of theRTE specifications.
“Against a backdrop of significant strain on energy markets and growing volatility in electricity prices, the ability to manage renewable energy is becoming a key challenge for the power system,” explains Grégoire Papion, President and Co-founder of Energies de Loire. At Energies de Loire, we have long been convinced that decentralized renewable assets can actively contribute to grid balancing. But beyond this conviction, we are moving forward step by step to demonstrate this in practice on the ground.
Last year, we were among the first companies to pilot a distributed solar array under the balancing mechanism, demonstrating that rooftop solar power plants can be effectively managed. In the fall, we commissioned one of the first standardized Huawei C&I batteries at our headquarters in Candé.
"Today, this new step toward certifying low-voltage batteries for secondary reserve capacity confirms a fundamental shift: renewable energy sources are no longer merely means of production; they are becoming hybridized and flexible assets capable of contributing in real time to the stability of the French power grid."
A strategic asset for the flexibility of the power system
Secondary reserve is a service essential to balancing the French power system, traditionally provided by hydroelectric and thermal power plants. The gradual opening of this market to decentralized assets (stationary batteries, flexible industrial sites) provides the system operator with faster, more distributed, and lower-carbon balancing resources.
By demonstrating its platform’s ability to control a battery asset down to low voltage with the required precision, latency, and reliability, Symphonics is positioning itself as an innovative flexibility aggregator for this segment.
About Symphonics
Symphonics is an integrated energy company specializing in smart energy management and the optimization of generation, storage, and consumption assets in energy markets. The company has established itself as a major player in energy aggregation, flexibility, and supply, and has expanded into several European countries. Symphonics offers “Managed Energy” solutions to help consumers and players in the renewable energy sector transition toward more competitive and sustainable energy. Certified by RTE and designated a Deeptech company by Bpifrance, Symphonics currently manages over 400,000 connected devices and actively supports the development and integration of renewable energy.https://symphonics.fr/
Press contacts Open2europe :
Florine Garreau: f.garreau@open2europe.com, 06 42 28 40 44
Anaïs Loyzance: a.loyzance@open2europe.com, 01 55 02 14 76
About Energies de Loire
Founded in 2018, Energies de Loire is a major player in the solar power sector in the Pays de la Loire and Brittany regions.
The company develops, builds, and operates solar power plants for a wide range of clients:
farms, industrial facilities, service sector companies, local governments, and more. With 120 employees and two
offices based in Candé (49) and La Baule (44), Energies de Loire manages over 800 power plants in
operation. Our belief: “Your energy is an opportunity—take back control!”
Our ambition: to provide long-term support to local stakeholders in transitioning to local, competitive, and
low-carbon energy.
To learn more about us:energiesdeloire.com
Press Contacts :
Mathilde CANILLAS: Communications Manager,mcanillas@energiesdeloire.com, 07 48 15 42 47
