Hydrogen/Fuel Cell
Hydrogen is the simplest element and consists of only one proton and one electron. It's also the most plentiful element in the universe. However simple and available, hydrogen doesn't occur naturally as a gas on the Earth - it's always combined with other elements. Water, for example, is a combination of hydrogen and oxygen (H2O). Hydrogen is very high in energy production, yet an engine that burns pure hydrogen produces almost no pollution.
The fuel cell, which has been highly touted as the future energy source to fulfill our needs, combines hydrogen and oxygen to produce electricity, heat, and water. Fuel cells are often compared to batteries. Both convert the energy produced by a chemical reaction into usable electric power. However, the fuel cell will produce electricity as long as fuel (hydrogen) is supplied, never losing its charge.
Fuel cells are a promising technology for use as a source of heat and electricity for buildings. In the future, hydrogen could also join electricity as an important energy carrier. An energy carrier delivers energy in a usable form to consumers. Renewable energy sources, like the sun and wind, can't produce energy all the time. But they could, for example, produce electric energy and hydrogen, which can be stored until needed. Much like electricity, hydrogen can also be transported to locations where it is needed.