the Bloom box is a new kind of fuel cell that produces electricity by combining oxygen in the air with any fuel source, such as natural gas, bio-gas, and solar energy. Sridhar said the chemical reaction is efficient and clean, creating energy without burning or combustion. He said that two Bloom boxes - each the size of a grapefruit - could wirelessly power a US home, fully replacing the power grid; one box could power a European home, and two or three Asian homes could share a single box.