Spatially and temporally resolved potential analysis and allocation optimization of power-to-gas plants in Germany

Kurzfassung

In order to meet emission reduction target, the energy system transitions into higher shares of RES and the use of conventional power plants is reduced. The rising share of RES increases the demand for flexibility options in the power grid. Power-to-gas plants are a much-discussed option that could provide the power grid with flexibility. Power-to-gas plants can be operated with surplus electricity to feed hydrogen and methane into the gas grid. In this way, power-to-gas plants contribute to the avoidance of congestions in the electricity grid. Since power-to-gas plants are intended to feed into the gas grid, the storage capacity of the gas grid represents a limiting factor for allocating power-to-gas plants. The aim of this work is to determine the spatially and temporally resolved installable capacity of power-to-gas plants at the level of MV Grid Districts. The installable capacity is calculated separately for the gas transmission grid and the gas distribution grid. Regionalization methods and load profiles are used to spatially and temporally resolve the installable capacity. The potential for feeding hydrogen and methane into the gas grid is determined in order to allow optimizations for the allocation of power-to-hydrogen plants and power-to-methane plants. The integration of the installable capacity into the power grid model eTraGo allows an optimization of the allocation of the power-to-gas plants considering the gas grid. The three research questions investigated are: how does the spatial distribution of the installable capacity of power-to-gas plants affect the allocation of power-to-gas plants, how does the temporal distribution of the installable capacity of power-to-gas plants influence the allocation of power-to-gas plants, and what is the impact of the maximum permitted concentration of hydrogen in the gas grid on the allocation of power-to-gas plants. The research questions are answered using six optimization cases. To determine the temporal influence, calculations are carried out for different periods of the year as well as for the entire year. Optimizations are performed with different permitted concentration of hydrogen in the gas grid to determine their impact on the allocation. The influence of the spatial distribution of the installable capacity of power-to-gas plants is investigated using all six optimization cases. The installable capacity of power-to-gas plants per MV Grid District strongly depends on whether the district includes only the gas distribution grid or also the transmission grid. The installable capacity of power-to-hydrogen plants feeding into the transmission grid is on average 860 MWel per MV Grid District. But the installable capacity of power-to-hydrogen plants feeding into the distribution grid is on average 1.5 MWelThe same applies to power-to-methane plants. Therefore, the plants are mainly built for feeding into the transmission grid. Increasing the maximum allowed hydrogen concentration in the gas grid results in fewer but larger plants built. In summary, the determined installable capacity of power-to-gas plants feeding into the gas grid can be used to determine an optimal allocation of power-to-gas plants taking into account the gas grid.