The Potential of Combined PV and Air Source Heat Pump Systems in German Residential Buildings
Abstract
Heat pumps are considered a cornerstone of the process of decarbonizing building stock. Especially in combination with electricity provided by rooftop photovoltaic (PV) systems, a large-scale roll-out of heat pumps will constitute a valuable element in the EU’s endeavor to increase both energy efficiency and the share of renewable power utilized in buildings. However, the installation of both PV systems and heat pumps is subject to various constraints, e.g., roof shapes for the former and available space for the latter. Therefore, we are investigating the feasibility of extensively implementing air source heat pumps combined with PV. This paper introduces a detailed spatial analysis of the available space around buildings that could be available for heat pumps, and couples it with an overview of the rooftop PV potential of these buildings. The analysis is carried out for two example regions in North Rhine-Westphalia, Germany. The results for the city of Cologne show that the combination of an outdoor air source heat pump with rooftop PV is feasible for 47% of residential buildings. In rural Winterberg, the share of suitable buildings is 74%. This illustrates both the potential for a large-scale roll-out of heat pumps in combination with PV in some regions, as well as the relevance of limiting factors such as available space in others. Furthermore, the results underline the importance of detailed spatial analyses for assessing the potential of the large-scale roll-out of heat pump–PV systems in Germany.