Importance of renewable resource variability for electricity mix transformation: A case study from Germany based on electricity market data

The success of the German electricity mix transformation depends on the variable renewable energies solar photovoltaics and wind. Their extensive exploitation until 2030 and beyond is a cornerstone on the road to climate neutrality, which Germany aims for in 2045. We use actual electricity generation and consumption data from 2015 to 2021 to analyze the development and potential of renewable energy shares in the German electricity mix and discuss future challenges for implementing the transformation until 2030. Current electricity consumption mostly exceeded renewable electricity generation, leading to consumption-supply mismatch and large residual loads. Renewable electricity generation met the net electricity consumption in 0.16% of all hours analyzed. No day renewables met net electricity consumption; substantial residual loads always occurred. The natural variability of the territorial availability of solar and wind was identified as the main reason for the high residual load shares. Results of a high-resolution wavelet analysis illustrate in detail the extend of the temporal, territorial variability of wind and solar along the studied timeline. Together with the annual gross electricity consumption values discussed for 2030 of 650-800 TWh these findings were used for projecting the future consumption-supply mismatch. The most optimistic scenarios show that only strict compliance with the targeted expansion and moderate increase in electricity consumption enables the achievement of set energy goals. Missing expansion targets and increasing electricity consumption challenge the 2030 renewable generation targets in 47% of the most optimistic scenarios. It is concluded that the natural variability of solar and wind will continue to be a major challenge for meeting Germany's electricity consumption in the near future.

Automated summary

The success of the German electricity mix transformation depends on the development and utilization of renewable energies. However, the current consumption of electricity exceeds the generation from renewable sources, leading to a supply-demand imbalance and significant residual loads. The natural variability of solar and wind power is identified as a major challenge for meeting Germany's electricity consumption in the near future.