Created by R.G., ZHAW, on 30.09.2024
PV systems on rooftops in the Central Plateau produce the most when the sun is shining. This means in the summer months around midday. Without seasonal storage options, this energy cannot be used directly in winter. As a result, there is usually an oversupply of PV electricity in summer and an undersupply in winter, when it is needed. Based on its own assumptions and using the total energy statistics for 2021 published by the Swiss Federal Office of Energy, the Solalpin interest group has calculated such a scenario for the year 2050. Swiss electricity consumption in monthly resolution for 2021 and 2050 is shown in the graph below. The light grey bars show the potential for PV on existing buildings by 2050, according to their calculations. Their sole use does not generate a high proportion of production in winter. The pink arrows show that there may be a gap in production during the winter months that will need to be filled by renewable sources.
Alpine PV offers support to fill this gap. It produces a considerable proportion of its energy in precisely those months in which a gap is expected. The qualitative graphic from BKW clearly shows the difference between Alpine, facade and rooftop PV systems. This indicates that Alpine PV systems can contribute a important part to a stable electricity supply in winter.
Alpine PV can close part of this gap and reduce future imports from other European countries. The second figure from Solalpine shows the scenario mentioned at the beginning, this time with Alpine PV yield. In this case, imports would only be needed for a few months in the depths of winter. It is therefore still important to rely on a mix of different renewable energy sources in order to guarantee the stability and security of the future electricity supply.
