ASTERIX-CAESAR: the innovative solar and energy storage technology led by CENER.
Behind the funny name chosen by CENER researchers for this new project lies one of the most promising technologies to make a real leap towards the long-sought total decarbonization of the energy system. The motto of this project refers to the “magic potion” of the famous Gaul warrior as the necessary recipe to create new adaptive solar power plants, capable of storing thermal and electrical energy during periods of high renewable generation and low demand (low price periods) and delivering electricity to the system during the hours of higher demand and lower renewable generation (high price periods marked by fossil fuels), without which it seems impossible to imagine a truly decarbonized energy system.
The innovative ASTERIX-CAESAR technology, based on an original idea from CENER and whose development is being led by this internationally renowned technology center, consists of the combination of concentrating solar thermal power plants (CSP) with tower technology – the most efficient and flexible solar power plants already featuring long-term thermal storage systems – with compressed air energy storage systems (CAES), in a hybrid combined-cycle configuration capable of providing an exceptionally competitive electrical energy storage technology (“the magic potion”) that in turn provides a breakthrough in solar-to-electricity conversion efficiency.
But the ASTERIX-CAESAR project goes even a step further and achieves a crucial conversion efficiency boost by using low-value surplus power from the grid – a clever trick that removes the compressor work of the topping Brayton cycle and results in much higher “expansion” efficiency than state-of-the-art combined cycles. This break-through approach reduces the maximum power cycle temperature (TIT) to about 800°C (compared to the classic combined cycle TIT of over 1,000°C), adds efficient electrical energy storage (CAES) to the power plant, and increases the peak solar-to-electric conversion efficiency to about 40%. A summary of all the technologies and their impact on the proposed technology can be seen in the following diagram.
The ASTERIX-CAESAR project has been submitted to the HORIZON program of the European Commission (HORIZON-CL5-2022-D3-03-01) in a proposal led by CENER, which has been awarded a grant of approximately 5.5 million Euros. CENER, in its role as National Renewable Energy Center, has coordinated a consortium with a large Spanish participation, maximizing the return of European R&D funds to the national academic, research and industrial network, which will receive slightly more than half of the grant awarded (2.9 million). Likewise, the project has a large number of European companies, R&D centers and universities that contribute to the project with the necessary experience and knowledge in different key aspects required for the development of the proposed technology.
ASTERIX-CAESAR partners are currently negotiating the Consortium Agreement to establish the main conditions that will govern the development of this technology and the Grant Agreement with the European Commission, essential steps for the project to be launched on October 1st, 2023 with the kick-off meeting to be held at CENER’s premises in Pamplona (Navarra).