Optimization of Electric-Gas Integrated Energy System Based on Reversible Solid Oxide Cell Considering Gas Composition

Power to Gas (P2G) technology can store electrical energy in the form of chemical energy on a large scale, promote the consumption of new energy, and strengthen the coupling between the power system and the natural gas system. Traditional power-to-gas mainly converts electrical energy into hydrogen, but there are problems in transportation and storage of a large amount of hydrogen. Compared with the traditional power-to-gas device, the reversible solid oxide cell (RSOC) has a very high conversion efficiency in both electrolytic gas production and fuel cell power generation modes. RSOC can also convert water and carbon dioxide into natural gas through co- electrolysis and the mixed gas is injected into the natural gas network to achieve efficient conversion and interconnection between electricity and natural gas. This work proposed a integrated energy system of power grid and gas network based on RSOC device. The RSOC part is modelled in detail and output gas composition of Hydrogen and SNG are fully considered. With the frame of Distflow and gas transport, a electricity-gas system is well established. The optimization model is solved with method of linearization to reduce the total operational cost. Result shows the RSOC contribute to energy utilization and cost reduction through flexible conversion between electricity and gas under different wind penetration senarios.