Distribution planning and pricing in view of increasing shares of intermittent, renewable energy in Germany and Japan

In response to the global climate challenge many countries are faced with increasing shares of energy from renewable sources in their power supply. The integration of RES (renewable energy sources) generation however entails technical as well as institutional challenges for power grids. This study relies on recent experiences of German distribution network operators in network planning and network pricing and looks at their transferability to Japan. Distributed generation may cause problems of voltage variation and asset overloading in conventional power grids. Technical solutions for these problems are available and well-known yet require considerable investments. The study presents regulatory incentives for network operators to take efficient means to maintain supply quality. With distributed generation self-supplying customers may contribute too little to network cost and new generators and flexible consumers may cause significant investment by uncoordinated siting and operation. An adequate pricing scheme can serve to sustainably finance the infrastructure while at the same time giving incentives to coordinate network users. This study points out options for network charging in grids with high shares of distributed generation from renewable sources.