A hybrid power system combining a solid oxide fuel cell (SOFC) and a gas turbine (GT) has the potential for very high efficiency in converting fossil fuels to AC electricity. Such a hybrid system offers an important and attractive feature: increasing the efficiency as compared to simple cycle fuel cell systems, and improving the efficiency and, at the same time, reducing the relatively high emissions as compared to gas turbine power systems. SOFC/GT hybrid systems have been considered for a number of power generation applications, e.g., distributed generation and on-site power plants. SOFC/GT hybrid systems can be integrated with a gasifier to form highly efficient coal-based central generation power plants. This paper discusses the development of planar SOFC technology for hybrid systems, several examples of hybrid system concepts and their performance characteristics, and key identified technical challenges.