Retrofitting parabolic trough CSP plants with PV and electric heaters for flexible dispatch and enhanced profitability

• An open-source co-simulation framework (ASDELSOL) was applied to optimize retrofitted CSP/PV/eTES plant operation using real market pricess. • The techno-economic impact of PV ratio, electric heater capacity and auxiliary tank volume was quantified for three hybrid configurations. • Electric heaters and auxiliary storage enhance flexibility, but their CAPEX limits NPV gains within a 12-year horizon. This study evaluates the techno-economic viability of retrofitting Concentrated Solar Power (CSP) plants with Photovoltaics (PV) and Electric Thermal Energy Storage (eTES)—thermal storage charged via electric heaters—to enhance dispatchability and profitability under current market conditions. Using the dynamic tool ASDELSOL, a predictive control strategy combines daily solar-resource classification with hourly electricity-price segmentation. Three configurations are assessed: (1) CSP + PV; (2) CSP + PV with a direct electric heater to TES; and (3) CSP + PV with an electric heater feeding an auxiliary thermal tank. In Scenario 1, baseload operation is benchmarked against price-driven optimization; the latter raises Net Present Value (NPV) across all PV ratios, peaking at €36.86 M for 25% PV. Scenarios 2–3 are analyzed under economic optimization, quantifying the influence of heater sizing and auxiliary-tank volume. While these components increase operational flexibility, their added cost does not pay back within 12 years; extending the investment horizon shifts the optimum toward higher PV ratios and improves the appeal of more integrated layouts. Overall, CSP–PV retrofits operated with market-responsive control are cost-effective, and adding electric heaters plus auxiliary storage can yield additional value under favorable market and investment assumptions.