Solid oxide fuel cells (SOFC) function like batteries that you can continually add fuel to. The Department of Energy's Pacific Northwest National Laboratory revealed a new type of SOFC yesterday, which achieves record-breaking efficiency in converting natural gas into electricity. SOFCs produce electricity by reacting negatively charged molecular oxygen with a fuel source, in this case methane from natural gas. The Laboratory's device combines in-house-developed "microchannel" technology -- allowing for more complete reaction of fuels -- with fuel and energy recycling to boost efficiency. The grouop is focusing on developing smaller, more locally focused systems to save on large-scale energy transport systems, which are generally less efficient. Their current system is designed to power one or a few typical American households, but are designing a larger system that would power 50-100 average American homes.