Thermal Energy Storage for On-demand Solar Trigeneration (TES4Trig)

Priority topic: 
Thermal energy storage
Project summary: 

The EU SET plan for CSP aims at electricity production costs of 10 c€/kWh for annual radiation of 2050 kWh/m2 by 2020. According to IRENA, in 2018, the levelized cost of electricity (LCOE) from CSPs was 18.69 c€/kWhe, while 0.5 GWe of new CSP plants were commissioned globally. To further reduce costs, the implementation of highly efficient, flexible CSP technologies equipped with thermal energy storage (TES) is necessary. Furthermore, significant cost reductions can be attained by combined cooling heating and power (CCHP) schemes that can receive additional revenue by covering the heating and cooling demands of utility, commercial or residential consumers.

TES4Trig aims at unifying the above strategies into a single innovative CCHP system driven by solar parabolic trough collectors (PTCs), based on the integration of the Organic Rankine Cycle (ORC) and Ejector Cooling Cycle (ECC) with a cost-effective TES system. In state-of- the-art large CSP plants, mostly molten salts TES systems are deployed. In TES4Trig, a concrete TES is proposed which has the potential to be more economic, simpler and environmentally friendly, but requires investigation to overcome operative barriers, accompanied with new PTC component designs and cost reductions.

Solar energy that is stored during periods of excess solar availability is used on-demand to produce electricity and domestic hot water (DHW) throughout the whole year, while space heating and cooling are additionally produced in winter and summer, respectively. The system will include a control system in order to enhance its flexibility and efficiently adjust electricity, cooling and heating outputs depending on the consumer needs. Within the project, the individual subsystems (PTCs, TES, ORC-ECC module) will be designed and integrated into a TES4Trig prototype, which will be demonstrated on-site of a consumer in Greece, in order to prove its feasibility and evaluate its actual performance in a real operating environment.

National Technical University of Athens
"DEMOKRITOS" National Center for Scientific Research Solar & other Energy Systems Laboratory
Aachen University of Applied Sciences Solar-Institut Jülich
CADE Soluciones de Ingeniería, S.L.
Protarget AG