The project aims to reduce the capital expenditure (CAPEX) by 30% and operating expenditure (OPEX) by 3-4% for the next generation Concentrated Solar Power (CSP) plants. This is being achieved through:
- Development of a new simulation tool for storage concepts in CSP plants.
- Providing guidelines for increasing the peak operating temperature up to 750 ºC.
- Designing and testing new laboratory-scale Phase Change Material (PCM) and high-temperature concrete storage systems.
- Identifying low-cost solid particle materials suitable for high-temperature CSP applications from a circular economy perspective.
- Designing and testing an advanced packed bed storage system capable of using multiple materials, reducing cost and storage volume.
A major technical goal is to develop novel Thermal Energy Storage (TES) solutions to enhance CSP plant efficiency and reduce costs. Over 50 performance indicators (PIs) were identified, categorized into technical, economic, and environmental indicators. The most relevant KPIs were selected and implemented into a simulation tool to assess the environmental and economic impacts of various TES concepts. This tool was validated using commercial software (SAM), showing good agreement between the simulation results for molten salt TES and concrete TES systems.
For the high-temperature concrete TES, a new formulation was created, capable of withstanding temperatures up to 750 ºC. The formulation showed good thermal conductivity and compressive strength, with an innovative modular storage tank design proposed to improve integration into CSP plants.
In the PCM storage concept, several units were manufactured and tested in a laboratory-scale setup. A study was also conducted to identify suitable PCM materials for storage. For solid particle storage, various waste materials were tested for compatibility with molten salts, and thermal aging tests showed changes in salt properties when in contact with materials like black slag, indicating potential salt degradation.
A novel radial flow packed-bed storage system was developed and tested. Results showed good thermal performance with a radial temperature difference of around 30 ºC. The system was evaluated with air as the heat transfer fluid (HTF), and temperature profiles showed effective charging and discharging at temperatures of 450 ºC.
Lifecycle assessments (LCA) and Life Cycle Cost (LCC) studies were conducted for several TES concepts. The results indicated that systems with thermal storage had lower environmental impacts compared to those without storage. LCA studies for various scenarios of reducing the amount of solar salt used in thermocline storage demonstrated the environmental benefits of alternative TES solutions, such as solid particles.
Additionally, economic indicators such as Levelized Cost of Electricity (LCOE), CAPEX, and OPEX are being studied to confirm the advantages of these TES technologies. These studies are key to evaluating the overall feasibility and sustainability of the proposed solutions in CSP plants.