A new urban district with over 500 residential units is being built in the sunny South of Germany, in Freiburg, which has become, a centre of solar energy and sustainability. The new district has assumed the role of a test and real-life laboratory for the Fraunhofer Institute for Solar Energy Systems. From the outset, renewable energies and energy-efficient technologies are to be used here. In summer, for example, heat will be generated in solar thermal systems and used directly by the residents. In winter, the heat will come from a block-type thermal power station, which will supply the district with heat for local use. The different types of use and the different heating requirements of the residents pose challenges with regard to the fluctuation of demand and the controllability of the heat supply.
This is where a project EnWiSol_II of the local heat supplier Badenova and the Fraunhofer Institute for Solar Energy Systems comes in: it will develop strategies for making the operation of CHP plants more flexible. This way, the overall efficiency of local heat generation is to be increased. Various operating modes are being tested for the “targeted supply” of energy to buildings with a heat accumulator. The heat stored in the buildings can then supply the local heating network for a certain period of time. Solutions are also to be found for the periods in which the local heating network is not in operation (for instance during maintenance work). In such cases, the buildings’ solar thermal systems are to be able to supply the partners’ local heating grid. All in all, the purpose of testing of new operating methods is to enable the overall system to respond more reliably to uncertainties and fluctuations.
The project is being funded by the Federal Ministry for Economic Affairs and Energy for three years until 2021.