The power to gas process concept is promising for the next generation of grid electricity storage and stabilization technologies. The electricity-driven fuel production can be chosen to be the efficient energy carrier for excessive grid power. Here, a reversible solid oxide cells system integrated with methane synthesis (ReSOC-MS) is proposed for the grid stabilization application at MW class. Besides H2, CH4 can be inclusively synthesized at grid surplus conditions as a transportation friendly energy carrier. A control strategy is proposed for this combined system, based on the grid state and H2 tank state of the system for the normal SOFC mode and SOEC mode operating. Simulation results of these two modes operating demonstrate that the ReSOC-MS can achieve an 85.34% power to gas efficiency at SOEC mode and 46.95% gas to power efficiency at SOFC mode.

The power to gas concept is promising for the next generation of electrochemical energy storage and grid stabilization technologies. The fuel produced from electricity-driven fuel production can be an efficient energy carrier for excessive grid power. Here, a reversible solid oxide cell(s) system integrated with methane synthesis (ReSOC-MS) is proposed for the grid stabilization application at Mega Watts class. CH ₄ can be synthesized at grid surplus conditions and can be a transportation friendly energy carrier. A control strategy is proposed for this combined system, based on the grid state and H ₂ tank state of the system for the normal solid oxide fuel cell (SOFC) mode and solid oxide electrolysis cell (SOEC) mode. Simulation results of these two operational modes demonstrate that the ReSOC-MS can achieve 85.34% power to gas efficiency in SOEC mode and 46.95% gas to power efficiency in SOFC mode. Dynamic simulations of stepping grid state for 5000 s operation show that the power to gas efficiency can be higher than 70%, thereby successfully demonstrating the capability of grid-balancing and methane production.