Integrated Smart Grid concept — Experience in a German distribution grid

The new German energy strategy – the so-called Energiewende – is mainly based on the large scale implementation of volatile renewable energy sources, like onshore wind and photovoltaic. As a consequence there are two tasks to be done. The first, time-based one is to keep the power balance between the fluctuating generation and consumption. This has to be managed by the implementation of a smart market which is coordinating flexible conventional power plants, demand side and – in future – storages. The second, location-based task is to manage the new high power and volatile load flows in the grids. The utmost challenge will occur in the distribution grid. By far the most of the new generation units will be connected there. In order to solve this challenge in an economic way the technical reserves of the existing grid have to be used. This means the transition from a static dimensioned grid to a dynamically operated grid. This approach is based on the availability of on-time load flow information and active load flow management. In general such a grid is a so-called “smart grid”. A very promising concept – called iNES – with a high strategic potential has been developed and implemented in Frankfurt.