Energetic optimization and local stability of heliothermal plant models under three thermo-economic performance regimes

Solar power plants have the advantage of not producing greenhouse gases into the atmosphere. In their operation, some design and construction parameters can be identified for improving their performance. In this work within the context of Finite-Time Thermodynamics (FTT), we analyze a Müser–Curzon–Ahlborn heat engine model by maximizing economic-objective functions which not only provide optimal operation modes, but also they can reduce the energy dissipated in the form of heat towards the atmosphere. In our thermo-economic study we take into account both investment as well as operation and maintenance (O&M) costs. From operation data of three commercial tower-power plants: Eurelios, Gemasolar and Ivanpah, we find optimal values of solar concentration (Cⁱ) for each economic-operation regime, accounting for the effect of internal irreversibilities (through a lumped parameter R). The Cⁱ-values that we found are in the range of current reported values for the three power plants aforementioned. Besides, we present a local stability analysis for the three aforementioned solar plants and we show that for large size plants, disturbed isothermal branches return faster to their respective steady states, in less dissipative regimes, (e.g. the ecological regime).