Deterministic power imbalances - measures to minimise the impact of high PV and battery storage penetration and electricity market rules

Assuming current market rules remain unchanged, the increasing penetration of photovoltaic (PV) systems and battery storage systems is expected to lead to an increase in Deterministic Power Imbalances (DPI) and thus Deterministic Frequency Deviations (DFD). The original cause of DPI can be traced back to covering continuously changing loads with generation based on hourly market products. This will increasingly be overshadowed by the balancing of continuously changing PV feed-in using fast battery storage, also based on hourly or quarter-hourly market products. Due to the scale of the problem − DPIs of up to 6 GW within a quarter of an hour are projected for 2030 based on a PV ramp of 13 GW/quarter hour − an effective solution must be found and implemented in the coming years. None of the promising countermeasures discussed in this paper offers a simple solution that can be implemented by transmission system operators (TSOs) alone. To sufficiently reduce the impact of DPIs, the option “additional provision of balancing energy” appears unsuitable due to the limited temporal responsiveness of aFRR. The option “trading with 5-minute products” has the potential to significantly reduce DPIs. However, implementation remains uncertain in the near future, especially within the European context. The option, “Requirements and incentives for ramping”, is generally considered to be a suitable countermeasure for significantly reducing the impact of DPIs. It is currently considered to be the option with the fewest obstacles in terms of implementation and is therefore discussed in greater detail as a potential solution.