Impact of a yearly reference period on the sliding feed-in premium for onshore wind in Germany

In Germany, support for onshore wind is calculated based on technology-specific monthly market values. To increase market integration of renewables, changing to a yearly reference period is under consideration. This reference period increases the price exposure and thus the overall risk for generators. To understand the effects and quantify this risk, we examine an individual turbine's average annual income at three locations in Germany between 2012-2018, as well as the maximum difference under the two alternative reference periods. We find no difference in income for strike prices between 0-15 EUR/MWh and a lower income under the yearly reference period for strike prices close to the nationwide market value (15-45 EUR/MWh). Starting from 45 EUR/MWh, we observe increased incentives for market integration. Furthermore, we find a maximum income loss of 3.6-3.9 EUR/MWh. Thus, although a yearly reference period could affect the income negatively, the difference is rather marginal.