Techno-economic feasibility of solar power plants considering PV/CSP with electrical/thermal energy storage system

Renewable-energy power generation can mitigate global climate change and contribute to achieving the goals of carbon peak and carbon neutralization. A solar power plant with flexible output and low power-generation cost is the desired goal; however, it is unclear which combination modes have superior economy and reliability in current economic scenarios or cost reduction scenarios. In this study, a solar power plant with many combinations, comprising a photovoltaic (PV) plant, inverter, concentrated solar power (CSP, including solar field, thermal storage system (TES), and power cycle), electric heater, and battery, is proposed. The levelized cost of energy and loss of power supply probability are selected as the evaluation criteria, and the capacities of each component are set as decision variables. In the current and cost-reduction scenarios, the feasibility analysis of the system is evaluated, and the optimal combinations and capacities of the components are acquired via multiobjective optimization. The obtained results are as follows. In the current scenarios, a system comprising TES has better economy and reliability than that comprising a battery, and the integration of CSP into the PV system can most economically improve the reliability. With the cost reduction of the energy storage, there is a strong competitive relationship between the battery and TES when the battery cost is reduced to approximately 160 USD/kWh. A solar power plant with integrated CSP is an effective method of enhancing generation reliability, although the battery cost is reduced to 60 USD/kWh. In cost-reduction scenarios, the advantages of the battery gradually become apparent, e.g., a PV plant with a battery has greater competitiveness than that with a TES. The integration of batteries into solar power plants is a promising future endeavor, while integrating CSP in a power plant would still be advantageous in current scenarios.

Automated summary

This study proposes a solar power plant with multiple combinations, including photovoltaic (PV) plants, thermal storage systems (TES) and batteries. By conducting multi-objective optimization, it is found that, in the current economic scenario, combinations including TES have better economy and reliability, and integrating CSP into PV systems can most economically improve reliability. With the reduction of energy storage costs, there is a competitive relationship between batteries and TES, but solar power plants with integrated CSP remain effective in enhancing generation reliability. In cost-reduction scenarios, batteries gradually show their advantages and integrating batteries into PV plants becomes more competitive.