Renewables account for a growing share of generated electricity. Efforts to integrate diverse energy sectors such as transportation and heating are making strides. These advances are giving rise to new challenges, particularly for distribution networks. Operators have to manage volatility, tame simultaneity, and avoid peak loads in consumer demand. Load shifting and intermediate energy storage can help strike the right balance between power generation and consumption, prevent loads and production levels from spiking, and deliver affordable energy. All this can be achieved by coupling different sectors and enabling the various players to collaborate. Such coordination and scheduling of energy use within a district or energy cell is necessary to take advantage of these flexibilities.
As part of a project that goes by the name of ENsource, the ZSW is looking into the value-adding benefits of optimizing entire districts’ or energy cells’ operations, and how this compares to optimizing individual power plants. This research effort addresses the matter on two levels – how to optimize energy management and take advantage of flexibilities centrally and locally at distributed plants, while also accounting for costs and system efficiency. Current energy market prices (see the figure below) are factored into the equation to determine how the central management entity interacts with smart distributed subunits. This entails demand-side management where the distributed units draw on price signals (2) based on dynamic energy market prices (1) and optimize their operations accordingly. The idea is to afford these smart distributed subsystems – that is, buildings equipped with control systems, combined heat and power, PV storage systems, and the like – as much autonomy and control as possible. The subunits also take into account the given power plant’s properties, load and, if necessary, yield forecasts (3) for their optimized generation and consumption schedules. They forward schedules and “flexibility bands” (4) to the central management entity to assess if these serve the higher purpose of overall optimization. The iterative process and this higher-order coordination of flexibilities creates a de facto internal market that cuts energy procurement costs and load peaks for the overall system. It can serve to generate additional revenue or save on purchased energy. Flexibilities could also be marketed externally (5). Given a suitable compensation structure, the district can behave in a way that serves the system.
The Urban ENergy Systems and Resource Efficiency project, or ENsource for short, is being pursued by the ZAFH, a network that brings together universities and non-university research institutes. The ZSW has joined forces with eight applied science universities in Aalen, Biberach, Heilbronn, Mannheim, Pforzheim, Reutlingen, Rottenburg and Stuttgart. The University of Stuttgart, and the Albert Ludwig University Freiburg, and the Fraunhofer ISE are also partners in this project. It is funded by the Baden-Württemberg Ministry of Science, Research and Arts (MWK) and the European Regional Development Fund (ERDF) to create value as part of the “Investing in Your Future” program.