Power-to-Gas Storage Optimization Through Power Pinch Analysis

Abstract

This work focuses on the optimization of an innovative power storage technology Power-to-Gas using pinch analysis. The concept of Power -to-gas storage is the conversion of power into gas that can be stored in the natural gas network. This concept incurs considerable power losses compared to other storage technologies. Besides, it has a long start time and a long stand-by recovery time that need to be studied. Graphical and numerical approaches have been developed for power optimization. A first graphical approach is presented. Then a numerical approach will facilitate more targeted responses to the problems experienced with the graphical one. This work acknowledges losses of the rectifier AC (alternating current) to DC (direct current), of the inverter (DC to AC), of the charging and the discharging process. This work proposes a new approach of Pinch Analysis Method for the optimization of Power-to -gas storage of a hybrid power system using intermittent and renewable energy. Graphical and numerical tools take into consideration new parameters (standby time, start time) and were applied to determine:The temporal time ratio of charging, discharging, stand-by time and rest;The minimum of outsourced electricity and the maximum of storage capacity.
Different scenarios for energy farms are presented and allow the designers to choose the best alternative for energy systems in a French City. Results show that the best alternative is an onshore wind farm. A sensitive analysis allows us to apprehend the importance of the source’s type in the optimization of the storage system.