Fuel cells convert the chemical energy stored in fuels into electricity and heat. They can be fed by fuels that are readily available as well as by waste-streams from industrial processes, thus reducing reliance on foreign oil and on an electricity grid that is ageing and increasingly pushed beyond capacity. As there is no combustion, fuel cells do not produce any emissions at their point of use, and because there are no moving parts, they are quiet and reliable. Due to their high efficiency, fuel cells are considered the most efficient means of converting any fuel to useful power, which they can provide at scales ranging from mW to multi-MW. They can be used in stationary applications such as generating electricity for industrial and residential applications where in many cases, the produced heat can also be used in transport, powering vehicles, buses and trains as well as off-road vehicles (e.g. forklift trucks) and in portable applications such as laptops, toys and cell phones.