Distribution network tariffs — The effect of decentralized generation and auto-consumption

Decentralized generation on the owners premises can be used on-site which we call auto-consumption. In a system with energy based (volumetric) network charges this reduces network income and in turn causes higher network charges on remaining usage with redistributional effects among customers. We estimate the effect from PV auto-consumption in Germany to be small in many network areas but significant in others leading to significant regional unequality. The effect may be self-enforcing and could increase strongly with pronounced shares of PV and auto-consumption. Further analysis should address the causal links to inform modifications to network charging for higher cost causality in power systems with high shares of (renewable) decentralized generation. Meanwhile a higher fixed component in network charges could be a pragmatic way to mitigate effects and serve a more equal participation of auto-consumers in network financing.