As the world gears up for the ongoing renewable energy revolution, the temporal variability of the renewable sources remains a big headache for designing a reliable electricity grid. A multi-level energy storage infrastructure is thus necessary to maintain high, year-round dispatchability. No technology that currently exists is ideally suited to meet...

Background An aircraft’s auxiliary power unit (APU) provides electrical and pneumatic power for such functions as lighting, ice clearing, engine starting, and cabin air conditioning. The use of dual chamber solid oxide fuel cells (DC-SOFCs) increases efficiency and reduces NOx emissions, but results in lower power densities compared to conventional...