Financial Viability of Grid-connected Solar PV and Wind Power Systems in Germany

The German electricity sector is in a period of transition, spurred by the German government's endeavor to maintain a sustainable, secure, climate-friendly and affordable energy supply system. The most important aspects of this Energiwende are the phase out of nuclear energy, promotion of renewable energy technologies, and reduction of greenhouse gas (GHG) emissions. As a consequence, huge investments in power generation systems and infrastructure are needed. Wind and solar photovoltaics (PV) are important renewable energy sources for achieving the goals, but power generation depends on spatial and meteorological conditions on site. For new build PV systems, the level of on-site solar irradiation is crucial, whereas the yield of wind turbines is mainly determined by the wind speed on site. In the model-based analysis with the RETScreen software, we distinguish between three different regions in order to take differences in climatic and geographical conditions in Germany into account. For each region, six locations with specific site conditions are used for the calculations. Projections are made for the base year 2015 and the future year 2030. We find that PV systems achieve levelized cost of electricity (LCOE) below 11 €-ct/kWh in 2030, with a GHG reduction potential of 133-289 €/tCO2. The LCOE of wind power ranges from 5.1-16.1 €-ct/kWh and the related GHG mitigation costs from 101-321 €/tCO2. In light of these results, it seems to be possible to restructure the German electricity generation system in a cost-effective and environmentally efficient way. Due to decreasing unit investment costs and increasing capacity, solar PV and wind power become increasingly competitive against conventional power generation. Hence efforts are needed to enhance and optimize the grid integration of wind energy and PV and to maintain the long-term security of electricity supply during the transition process.