A complex, three-phase power grid is operated as a microgrid at RIZ Energie, fed from renewable energy sources as far as possible. Three photovoltaic generators, with 2.16 kW peak power each, provide a significant contribution from solar energy. For intermediate energy storage, stationary batteries of various technologies are charged, or the traction battery of the University's electric vehicle is ‘refueled.’ Various switchable loads can be integrated into the power grid as energy users. Electronic loads allow different use cases to be emulated, from single-family homes to small commercial operations. The energy supply from renewable energy sources is supplemented by a wind generator with 5.5 kW peak power.
Intelligent control of the individual components is achieved using a predictive energy management system that figures in weather, demand and usage projection data. An example of an important application area is grid-serving control, where the microgrid communicates with external partners via the built-in smart meter gateway like a smart grid, and either consumes or releases electricity depending on the state of the higher-level grid, or the market.
The automation and communication structure is PLC-based, with direct coupling to the management level of the microgrid. This allows the complex interaction of data acquisition from meters and network states, regulation and control, and yield-and-demand forecasts to be mapped in an energy management system.