Analysing Grid-Level Effects of Photovoltaic Self-Consumption Using a Stochastic Bottom-up Model of Prosumer Systems

Self-consumption of the energy generated by photovoltaics (PV) is playing an increasingly important role in the power grid. Prosumer systems consume part of the produced energy directly to meet the local demand, which reduces the feed-in into as well as the demand from the grid. In order to analyse the effects of PV self-consumption in the power grid, we introduce a stochastic bottom-up model of PV power generation and local consumption in the control area of the German transmission system operator TransnetBW. We set up a realistic portfolio of more than 100,000 PV/prosumer systems to generate representative time series of PV generation and consumption as a basis to derive self-consumption and feed-in. This model allows for the investigation of the time-dependent behaviour in detail for the full portfolio whereas measurements are presently only available as aggregated feed-in time series over a nonrepresentative subset of systems. We analyse the variation of self-consumption with PV generation and consumption at the portfolio level and its seasonal, weekly and diurnal cycles. Furthermore, we study a scenario of 100% prosumers as a limiting case for a situation without subsidized feed-in tariffs and local energy storage.

Automated summary

The self-consumption of energy generated by photovoltaics (PV) is increasingly important in the power grid. A stochastic bottom-up model of PV power generation and local consumption was introduced to analyze the effects of PV self-consumption in the control area of TransnetBW, the German transmission system operator. By setting up a realistic portfolio of over 100,000 PV/prosumer systems, representative time series of PV generation and consumption were generated to derive self-consumption and feed-in. The analysis focused on the variation of self-consumption with PV generation and consumption at the portfolio level as well as its seasonal, weekly, and diurnal cycles. A scenario of 100% prosumers was also studied, considering a situation without subsidized feed-in tariffs and local energy storage.