Solid Oxide Fuel Cell Power System Cycles

Abstract

Reviewed are power system concepts employing the solid oxide fuel cell (SOFC) at atmospheric pressure in simple cycle; in an atmospheric pressure hybrid cycle with a gas turbine (SOFC/GT); and in a pressurized SOFC/GT hybrid (PSOFC/GT). Estimates of power system performance are presented and discussed. Simple atmospheric pressure SOFC systems designed for combined heat and power (CHP) application can approach 50% electric generation efficiency (net AC/LHV) and 80% fuel effectiveness [(net AC + useful heat)/LHV]. Pressurized SOFC systems with intercooled, recuperated, and SOFC-reheated GT cycles can approach 70% electric generation efficiency, while the atmospheric pressure SOFC/GT hybrid cycle and a simple pressurized SOFC/GT cycle can approach 55% and 60% generation efficiency, respectively. These high levels of efficiency are extraordinary in that they are achievable at the MW capacity level.