To make electricity, fuel cells require just hydrogen, plus oxygen easily taken from air. A catalyst in the fuel cell splits each hydrogen atom into a proton and an electron, the protons pass through a membrane to combine with oxygen and the reaction produces water. At the same time, the membrane forces electrons to take an external circuit to the other side of the membrane. In doing so they make power. Five main types of fuel cells, with different electrolytes and operating temperatures ranging from 80 C to 800 C, lend themselves to all types of applications.
Obvious uses involve buildings, which consume two-thirds of the nation's electricity.
Besides generating power, fuel cells produce high-quality waste heat that can be used for heating and refrigeration. They already make economic sense where the existing power grid is fully loaded and expansion is costly, such as in rural areas where there is no power grid, or where high-quality assured power is a necessity. Generating power where needed further eliminates huge costs associated with putting in miles of expensive wires on the grid. Using fuel cells to generate decentralized power also minimizes transmission losses and delivery costs. Nationwide, the cost of delivering electricity from all sources runs about 2.4 per kwh.