HYSTORE: Smart Thermal Storage for a Flexible Energy Future
The Energy Storage Challenge in Renewable Energy Transition
One of the key challenges of the energy transition is not only producing renewable energy, but ensuring it’s available when and where it’s actually needed. This is where energy storage becomes essential. The Horizon Europe project HYSTORE is tackling this challenge with an innovative thermal energy storage prototype that offers a smart, flexible, and cost-effective alternative to conventional systems.
How Latent Thermal Energy Storage Technology Works
Developed by German company Rubitherm, the prototype uses latent thermal energy storage technology. Unlike traditional systems that store energy by heating water or other materials (sensible heat storage), latent storage harnesses the power of phase change.
At its core is SP31, a salt hydrate with a remarkable property: it absorbs large amounts of heat while melting and releases that energy when solidifying, all at a nearly constant temperature. This phase-change process allows far more energy to be stored in a compact space compared to conventional methods. Think of it as a thermal “battery” that charges and discharges using heat instead of electricity.
Pictures of the prototype taken in Messina at the CNR premises before being shipped to Montserrat.
Modular Design and Cost-Effective Components
What sets the HYSTORE concept apart is its modularity. The prototype incorporates a low-cost plastic heat exchanger, proving that cutting-edge energy storage doesn’t require expensive or complex components. Each module operates independently, making it easy to scale systems up or down based on specific needs.
The module tested at CNR has a 10 kWh storage capacity and has been rigorously evaluated under part-load conditions—simulating the fluctuating energy demands of real-world operation.
Thermal Storage for Grid Stabilization and Peak Demand Reduction
These tests reveal something crucial: thermal energy storage can do more than just store heat. It can actively stabilize the electrical grid. While batteries often dominate discussions about grid management, thermal storage systems like HYSTORE play a vital complementary role.
By storing heat during periods of abundant renewable electricity (such as sunny or windy hours) and releasing it later, the system reduces peak electricity demand. This makes the grid more stable, efficient, and resilient—particularly important as heating and cooling become increasingly electrified.
Real-World Demonstration at Montserrat Pilot Site
HYSTORE isn’t confined to the laboratory. The prototype has already been shipped to the Montserrat pilot site, where it will be demonstrated at Technology Readiness Level 7. Over the coming year, real-world results will showcase the tangible benefits of this technology in actual operating conditions.