As the overarching goal of decarbonising the economy intensifies, the electricity sector faces mounting challenges, particularly in ensuring supply security and grid stability. Large-scale energy storage has become one of the critical challenges of today’s energy systems, driven by the increasing share of renewable energies. This transition necessitates a shift in storage duration requirements, moving from intraday to interday storage solutions.
Exploring the role of storage technologies
The webinar delved into the pivotal question: What role can storage technologies, especially power-to-heat-to-power systems, play in addressing these challenges? Leading research institutions provided a comprehensive technical and scientific overview of state-of-the-art technologies and future advancements.
A key focus was the integration of high-temperature thermal storage and power-to-heat systems, which enable a reliable and cost-effective “on-demand” heat supply from renewable electricity. Adding storage not only stabilises the fluctuating electricity supply but also reduces electricity costs while enhancing grid flexibility. When extended with a power cycle, such storage systems offer even greater flexibility, functioning as a Carnot Battery.
Promising applications and technical insights
The event highlighted promising applications of these solutions for district heating and industrial processes. Additionally, it explored cost reduction and efficiency improvements achievable through optimised storage design and the precise matching of power and storage components. Technologies such as Phase Change Material (PCM) Storage, Molten Salt Storage, Solid Media Storage and Thermochemical Storage were discussed as key innovations in this field.
One of the featured technologies was a utility-scale pumped heat long-duration energy storage system, which demonstrated the ability to provide both:
- flexible, cost-effective long-duration electricity storage and
- essential grid reliability services, including synchronous inertia, short circuit current, reactive power, black start capability, and frequency support.
Unlike other energy storage technologies, this system is uniquely decoupled in terms of power and duration. It can operate at any power level between minimum and full rated power for both charging and discharging, adapting seamlessly to application demands. It was presented as a viable replacement for natural gas-fired power plants.
Case study: Decarbonisation of the Mělník Power Plant
An in-depth case study of the Mělník power plant provided insights into its decarbonisation journey. This included the integration of new power sources, interconnections with renewable energy and storage systems, and the deployment of pilot projects such as a molten salt demonstration unit and advanced supercritical CO2 cycles.
Innovative hydrogen-based storage systems
The event also introduced a hydrogen-based energy storage solution for demand-driven use of renewable energy. By integrating an iron-based storage system with Solid Oxide Electrolyser Cells (SOEC) and Solid Oxide Fuel Cells (SOFC), the efficiency of the system can reach approximately 66%. This approach is particularly suitable for flexible, on-demand power supply applications.
Key takeaways
Heat storage and power-to-heat processes are emerging as critical tools for improving the flexibility, efficiency, and sustainability of industrial heat supply. Their relevance extends beyond industrial processes to broader grid applications, showcasing their potential to support the energy transition.
The event underscored the importance of continued development and of these technologies, which will undoubtedly be followed with keen interest in the future.
