Energy Storage Systems for Very High Altitude Very Long Endurance Solar Aircraft

Solid oxide fuel cell (SOFC) systems are forecast to achieve excellent energy efficiency and performance targets, and to be able to achieve commercially viable economics through the next decade. The NASA Glenn Research Center (GRC) has been working on SOFC technology for the aeronautics’ industry for several years and their approach is significantly different than the approaches being pursued by the Department of Energy’s Solid Energy Conversion Alliance companies. The NASA Bi-Electrode Supported Cell (BSC) SOFC technology has the potential to provide a significant increase in power performance per weight (W/kg) and increased reliability of the fuel cell stack. ENrG has an agreement with NASA to continue development and commercialization of the technology. For applications such as very high altitude, very long endurance solar aircraft, the BSC technology offers the potential to significantly reduce the weight of the fuel cell stack compared to PEM technology and increase the conversion efficiency of both the fuel cell and electrolyzer. In addition to the direct savings from the use of the NASA SOFC technology, the use of SOFCs has enabled our team to identify several other significant weight reductions from the balance of plant needed to operate the fuel cell stack and fuel storage system.