Economics of Public Charging Stations in Solar-Covered Parking Lots Under the German GHG Quota

This paper analyzes the charging station business case for a solar-covered parking lot, in particular regarding the German economic instrument greenhouse gas quota (GHG quota). It thus combines two legislative changes that have occurred in Germany: the obligation for parking spaces to be covered by solar energy systems and the economically improved possibility of additional revenue for solar energy systems combined with charging stations through the GHG quota. This charging station business case is examined in scenarios with different power and quantity of charging points for different values of the GHG quota. The aim is to determine the minimum utilization required for the charging station in order to be more economically viable compared to feeding power directly into the grid. The analysis shows that the GHG quota can reduce the required minimum utilization of the charging stations by up to 55%. With the current GHG quota value of about 150 €/t_CO2eq, most of the scenarios considered are at an average charging station location more economically viable, for example the AC5 scenario with an AC charging point at every fifth parking space. A charging price that is reduced by 50% during simultaneous solar power production incentivizing charging in such situations can further increase the economic viability depending on the value of the GHG quota value.