The European Union has the goal to reduce greenhouse gas emissions by 80% to 95% compared to 1990 levels by 2050, mainly by introducing more shares of renewable energy sources. Solid oxide technologies are key enabling technologies for allowing for such integration. Solid oxide cells (SOCs) devices are efficient and clean power generator and highly efficient converter of electricity to hydrogen (SOFC), fuels and chemicals using high temperature electrolysis (SOEC). These devices can balance the fluctuating nature of electricity from renewable sources by changing dynamically operation mode between SOFC and SOEC (rSOC) in a reversible way. Although their development still faces various problems with high-temperature materials compatibility, durability and integration processes, SOCs are expected to enter the commercial markets in the near future.The enhanced efficiency and durable electrochemical energy conversion in SOC systems can be achieved by suitable material choice and processing and a reliable integration and joining technology.