The role of residential photovoltaic-coupled battery storages in the energy system from a regional perspective

The electric energy systems face a fundamental transformation triggered by the tackling of climate change, the long-term depletion of fossil fuels and the cost-decrease of renewable technologies. Especially photovoltaic (PV) energy installed on rooftops has become a major driver of the current energy transition. Residential buildings are often additionally equipped with battery storages raising the self-consumption of PV energy by the balancing of load and production. The increasing decentralization of the energy generation systems represents a challenge for the grid infrastructure, which has not been dimensioned for the feed-in on low voltage level in the past. This dissertation assesses the impact of residential PV-coupled battery storages on the energy systems from a regional perspective under consideration of the great multitude and heterogeneity of the systems. The divergence arises from the differences in equipment, PV sizes, battery capacities, efficiencies and consumption loads, but also from locally varying meteorological conditions. For reproducing this spatial variance, the raster-based land surface processes model Processes of radiation, mass and energy transfer (PROMET) is extended by a residential consumption, a PV and a battery storage component. This allows a physically based simulation of the energy flows considering the individual parameterization of the residential buildings and their spatiotemporal dependencies. The application of this model approach shows that the choice of the battery charging has a crucial influence on the regional integration of rooftop PV but also on the increase of PV self-consumption. The utilization of daily, dynamic feed-in limitations yields the highest reduction of residual loads while also maximizing self-consumption. The application of this charging strategy should be supported especially for larger PV and battery storage systems in order to reduce grid impacts. Apart from the battery management, the PV and battery expansion plays an essential role for their grid integration on regional scale. The diversity of residential energy systems offers further balancing potential due to the spatial variance in their residual loads. The highest regional grid-balancing is obtained when 30% of the buildings is equipped with PV systems. In this case, the additional utilization of battery storages reduces this effect to the benefit of higher self-consumption rates and therefore does not contribute to the reduction of grid excesses. This is different for high PV installation rates, as grid balancing diminishes. For this reason, financial support for batteries should be adjusted to the regional PV installation rates. Apart from the management strategies and expansion rates, the climatological and consumption-related boundary conditions have crucial impact on residential batteries and their potentials for increasing self-consumption and grid-relief. Both factors will undergo significant changes in the future. Scenarios until 2040 project that climate change affects the battery utilization in winter, whereas the effects of efficiency enhancement of domestic appliances dominates in the summer. The resulting increase in PV excesses could rise grid stresses further. In order to reduce potential losses, these developments should be considered in the dimensioning of batteries. The results show that the spatial variance between residential energy systems has a crucial impact on PV-coupled battery storages on regional scale. The developed approach, which is based on the extended utilization of a land surface processes model, offers the possibility to simulate the interactions between the residential energy flows for a multitude of buildings and to map regionally adjusted strategies for the integration of PV systems.