Hydrogen is an energy carrier. Electricity from wind turbines, for instance, can be used for hydrogen production. Hydrogen can be stored, whereas electricity must be used the moment it is generated. Hydrogen can therefore be used for storing energy, which can be converted into energy again by burning the hydrogen in a gas turbine, for example, or by converting it in a fuel cell.
A fuel cell converts hydrogen or natural gas into electricity without any pollution. A fuel cell can make electricity and heat, and water is the only waste product in the process. That is why the use of hydrogen and fuel cells is most environmentally-friendly in the overall energy production provided that the hydrogen is produced from renewable energy sources such as wind energy.
Fuel cells can be used in the transport sector, in small household installations – so-called micro CHP – as uninterruptible power supply systems and, on a larger scale, at CHP plants. Denmark is at the forefront of development of the two fuel-cell types, PEMFC and SOFC, and aims at micro CHP with fuel cells in private households.