The PGS institute is investigating the cost structure of BESS in order to improve its economic viability. For that reason, battery performance and ageing tests are carried out in the institute’s laboratories in order to identify each battery type’s characteristic electrical and aging parameters. Sophisticated battery models are derived from the obtained data which allow simulations of the complex behavior of each battery type involved in the project. These battery models are utilized to develop real-time optimization of the hybrid BESS operation, which is implemented as model-predictive-control (MPC). This MPC aims at minimizing the total life cycle-cost of BESS operation by controlling the load allocation among the different battery types in an intelligent manner. The optimized operating strategies are also used to develop simpliƄed heuristics, which can be implemented on industrial type, low-cost hardware with possible cost beneƄts. Additionally, PGS contributes to operation concepts and examines the BESS operation economics. Therefore, the BESS is integrated into the energy market and will be operated under realistic market conditions. All aspects provide the foundation for an extended evaluation of economic parameters, and new insights into design considerations for MW-scale BESS. PGS also carries out a two-fold analysis of the power-electronic interface for such a BESS. One aspect deals with the optimized operation of the conventional approach using a low-voltage (LV) inverter followed by a step-up transformer. The second aspect of the PGS investigation pertains to the novel concept of medium-voltage (MV) voltage-source converters (VSCs). The main aim of this concept is to increase the use of silicon by employing suitable power-electronic converters and to decrease the use of iron and copper, mainly found in the bulky line-frequency step-up transformers, hence reducing the overall system cost. Topics related to trading potentials of the BESS are conducted by the IAEW institute. Currently, the most beneƄcial trading option for BESS in terms of economic outcomes is the provision of primary reserve control. Alternatives such as secondary reserve control, participation in the electrical spot market and pooling with various different generation units are also considered. The EBC institute investigates the thermal energy ƅows of the BESS. Thermal models for all types of batteries are developed, which provides holistic simulation opportunities in combination with the electrical models. Another part of the analysis covers the electrical power consumption of the heating, ventilation and air conditioning (HVAC) system as this causes the largest share of the BESS’s self-consumption.
Coupling of Heat and Electricity Market: Combination of Heat and Electricity Systems in Household The growing share of Ć…uctuating renewable electricity generation requires Ć…exibility and balancing capacities in the electricity network. Storage systems and demand side management (DSM) are valuable solutions to provide the necessary balancing capacities. Larger on-shore wind parks are connected on medium to high-voltage levels and off-shore installations will be connected directly to the transmission grid. Within the last two decades, over 1.5 Million PV systems were installed in Germany. Most of those are placed in the low-voltage distribution network. Consequently, Ć…exibility solutions have to be found at the different levels of the electricity grid. For the low-voltage system, so called prosumer households, which are producer of their own electricity while still connected to the grid, could deliver additional Ć…exibility through directed demand-side management. In particular, the Ć…exibility gained from the interaction of the electric and the thermal system with the corresponding storage systems is of great interest.
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Table 1: Basic cost assumptions for scenario calculation
Chapter IV | 103