Solar Infeed During Low Demand Hours - A Problem?

This paper addresses negative electricity prices resulting from the integration of renewable energy sources into power systems. We show that a significant share of renewable capacity, particularly solar and wind, are unresponsive to negative prices. The study presents two scenarios for future excess generation in the German electricity system: a business-as-usual scenario and a scenario with enhanced demand-side flexibility. Results show that without increased demand flexibility, the system could face excess generation, i.e. supply exceeding demand at the lowest price currently allowed (-500E/MWh), of up to 15 GW by 2027, with negative prices causing significant market disruption. Conversely, the extended demand flexibility scenario could mitigate these issues significantly. The findings underscore the necessity for demand-side flexibility and efficient curtailment of RES output.