The article discusses the operation of solid oxide electrochemical cells (SOC) developed in the Institute of Power Engineering as prospective key components of power-to-gas systems. The fundamentals of the solid oxide cells operated as fuel cells (SOFC - solid oxide fuel cells) and electrolysers (SOEC - solid oxide fuel cells) are given. The experimental technique used for electrochemical characterization of cells is presented. The results obtained for planar cell with anodic support are given and discussed. Based on the results, the applicability of the cells in power-to-gas systems (P2G) is evaluated.
 Milewski J., Wołowicz M., Lewandowski J.: Optimization of the working conditions of a laboratory size (100 cm2) molten carbonate fuel cel l. ECS Transactions 51(2013), 1, 37-45.
 Schwarze K., Posdziech O., Kroop S. et al.: Green industrial hydrogen via reversible high-temperature electrolysis. ECS Transactions 78(2017), 1, 2943-2952.
 Pozzo M., Lanzini A., Santarelli M.: Enhanced biomass-to-liquid (BTL) conversion process through high temperature co-electrolysis in a solid oxide electrolysis cel l (SOEC). Fuel 145(2015), 39-49.
 Virkar A.V.: Mechanism of oxygen electrode delamination in solid oxide electrolyzer cel ls. Int. J. Hydrogen Energ. 35(2010), 18, 9527-9543.
 Sun X., Chen M., Jensen S.H., et al.: Thermodynamic analysis of synthetic hydrocarbon fuel production in pressurized solid oxide electrolysis cel ls. Int. J. Hydrogen Energ. 37(2012), 22, 17101-17110.
 Graves C., Ebbesen S.D., Jensen S.H., et al.: Eliminating degradation in solid oxide electrochemical cel ls by reversible operation. Nat. Mater. 14(2015), 239-244.
 Jae S., Gyeong K., Choi M.: Stability of LSCF electrode with GDC interlayer in YSZ-based solid oxide electrolysis cel l. Solid State Ionics 262(2014), 303-306.
 Kim S.J., Kim K.J., Dayaghi A.M., et al.: Polarization and stability of La2NiO4+δ in comparison with La0.6Sr0.4Co0.2Fe0.8O3-δ as air electrode of solid oxide electrolysis cel l. Int. J. Hydrogen Energ. 41(2016), 33, 14498-14506.
 Hansen J.B.: Solid oxide electrolysis - a key enabling technology for sustainable energy scenarios. Faraday Discuss. 182(2015), 9-48.
 Milewski J.: Solid oxide electrolysis cel l co-methanation supported by molten carbonate fuel cel l - a concept. J. Power Technologies 96(2016), 1, 8-14.
 Bartela L., Skorek-Osikowska A., Kotowicz J.: Integration of a supercritical coal-fired heat and power plant with carbon capture instal lation and gas turbine. Rynek Energii 100(2012), 3, 56-62.