WP1 – Techno-economic and sustainability analysis (lead UNIGE)
WP1 provided baseline models for the techno-economic analysis and optimisation of sCO2 plants for mid-range power layouts (1–10 MWe size), as well as small-size plants (less than 1 MW), potentially including Tesla-type turbomachinery. Plant optimisation was carried out considering both performance features and eco-design key indicators. WP1 also provided guidelines for identifying the most profitable opportunities in the energy market, based on the Italian grid code (as a representative example of a European grid code).
T1.1 developed models for reversible sCO2 cycles to be employed as energy storage systems, with possible external energy inputs (e.g., CSP or WHR where available). Based on the WTEMP software, proprietary to UNIGE, various cycle configurations were analysed and optimised. From a thermodynamic perspective, the aim was to maximise round-trip efficiency (RTE) while maintaining acceptable plant complexity. From an economic perspective, the objective was to minimise thermal load requirements on heat exchangers and the total thermal energy storage requirement.
Different assumptions and turbomachinery surrogate models from WP2 (developed by POLIMI) were used to carry out trade-off analyses between RTE and CAPEX (estimated through tailored cost functions), identifying the most promising layouts and related design point parameters.
T1.2, led by UNIFI, focused on the environmental and economic assessment of the selected systems and layouts in life cycle analysis terms. The best eco-designs were identified through quantitative multi-objective cost functions, incorporating various key performance indicators (e.g., global warming potential, carbon footprint, emissions, etc.).
T1.3 involved all partners (UNIGE, POLIMI, and UNIFI), who investigated the most promising market niches within the Italian electrical grid scenario, taken as representative of a large EU electrical grid. The study identified the most common climate, geographical, and economic features indicating high profitability potential for such sCO2 storage systems, including configurations such as antenna-type electrical networks.