ESRI Energy Research Seminar
Venue: ESRI, Whitaker Square, Sir John Rogerson’s Quay, Dublin 2
Multi-criteria evaluation of transition pathways towards a sustainable energy system
Speaker: Professor Jutta Geldermann, University of Göttingen, Germany
Authors: Katharina Stahlecker, Jutta Geldermann
Germany’s long-term energy policy targets envision an energy efficient system primarily based on renewable energies. Thereby the greenhouse gas emissions should be reduced by 80% until 2050. This transition towards a sustainable energy system involves multiple conflicting criteria. Technically feasible options need to be assessed considering economic and social sacrifices and environmental impacts. Within the publicly funded project NEDS, researchers from different disciplines are developing feasible transition pathways towards a sustainable energy supply in 2050 for the German federal state of Lower-Saxony. The aim of this research project is to evaluate the sustainability of different scenarios and transition pathways. Multi-criteria decision analysis is used to simultaneously consider technological, economic, environmental and social criteria. Due to the long-term nature of the decision problem, the analysis needs to take uncertainties and path dependencies into account.
Professor Jutta Geldermann
Jutta holds the Chair of Business Administration, especially Production and Logistics, at the Faculty of Economic Sciences of the University of Göttingen. After her diploma in “Industrial Engineering” at the University of Karlsruhe, she had worked on her PhD and her habilitation (post-doctoral lecture qualification) at the French-German Institute of Environmental Research and the Institute for Industrial Production at the University of Karlsruhe. She is an internationally renowned expert in the fields of multi-criteria decision support in the context of cost-effective and ecology-oriented design of production and logistics systems. She is experienced in many third-party funded projects for the EU, numerous ministries on national and regional level and for the industry, including SME. She is member of the board of the energy research center of Niedersachsen (efzn).
Operating Strategies for Battery Storage Systems in Low-Voltage Grids to Limit the Feed-In Power of Solar Power Systems Using Fuzzy Control
Speaker: Tobias Lühn, University of Göttingen, Germany
Authors: Tobias Lühn, Jutta Geldermann
Germany’s energy turnaround is leading to an increasing integration of photovoltaics (PVs) throughout its distribution grid. Because the power generation of PVs fluctuates greatly, distribution system operators (DSOs) are faced with the challenge of preventing grid component overload and voltage range violations. One solution might be to integrate battery storage systems in private households and reduce active peak power at the grid connection point. Since peak shaving is often impossible with the conventional operating strategy of the storage system, PV-plants must sometimes be throttled back. In this study, we introduce a fuzzy control system (FLC) that reduces peak feed-in and thus also energy losses due to throttling back PV power. The FLC uses solar surplus and battery charge level as input parameters, and standardizes them to ensure easy adjustment to different combinations of PV plant sizes and storage capacities. To obtain good results, the set of numerical parameters of the membership functions is enhanced by evolutionary programming. This grid-optimized operating strategy is only applied on days with high solar forecasts. To evaluate the robustness of the grid-optimized operating strategy, we simulate load flows for a complete year in MATLAB with a high time resolution using real-world measurement data from a PV plant and the power consumption of a household. Based on the simulation, we then perform an energetic and economic assessment of the two operating strategies. Our results show that even small electrical storage capacities (<<5 kWh) reduce energy losses considerably and produce only small losses in selfconsumption. Thus, there is an economic benefit for plant operators who switch from the conventional to the grid-optimized operating strategy. Moreover, solar forecast inaccuracies and variations in load and generation profiles have a negligible impact on the performance of the control algorithm.
Tobias Lühn
Tobias received his diploma in industrial engineering and management from RWTH Aachen University, in 2012. Since 2012, he has worked as a research assistant at the Chair of Production and Logistics at the Faculty of Economic Sciences of the University of Göttingen. His research focus is on the integration of renewable energy, especially photovoltaics, into the low voltage grid.