Hydrogen consists of two hydrogen atoms with the molecular formula H2. It is the lightest and most abundant chemical element. Hydrogen is a gas under standard temperature and pressure. Energy density is high per unit mass, but low per unit volume. The latter makes hydrogen difficult to store and transport efficiently. The most common methods of storing hydrogen are either to compress it and store under pressure at 200-700 bar, or alternatively to store it in a liquid state, which it reaches at -253˚C.

Today, hydrogen is used as a resource in the chemical industry, for example in ammonia production which then can be used to produce fertilizers. Another area where hydrogen is of big use is in refineries where crude oil is transformed into petroleum and diesel. Hydrogen has been used in industries for more than a century, resulting in a great deal of experience and knowledge on how to handle the gas safely.

In addition, hydrogen is an energy carrier, similarly to electricity. This means that hydrogen is not a primary energy resource. Instead it can be used to store, transport or supply energy. Hydrogen provides great flexibility since it can be produced out of any form of energy source. Today, the source of production of hydrogen is primarily natural gas, but in the future renewable energy from sunlight, wind, biogas and biomass will be used to a greater extent. Furthermore, hydrogen is generated as a by-product in chemical industry. This could function as a source of hydrogen during the introduction phase, before large-scale hydrogen production from renewable sources can be achieved

A future area of use for hydrogen is as energy in fuel cells. A fuel cell is a transformer of energy which efficiently can be used to transform the hydrogen’s chemical energy into electricity and heat. The only by-product is pure water. The efficiency of a fuel cell is high, which often compensates for the loss of energy when producing hydrogen.

Fuel cells powering electrical engines can replace combustion engines in vehicles and be used to heat houses. They can also be used in smaller units, such as cell phones, computers or power devices for leisure boats. There is, or will be within shortly, commercially viable technology for both portable and stationary appliances.

Did you know that…?

• Hydrogen is more than 14 times lighter than air and disappears quickly in open spaces.
• Hydrogen combusts rapidly without producing any smoke.
• In order for there to be a risk of explosion oxygen must penetrate a closed container of hydrogen.
• It was not hydrogen that caused the airship Hindenburg to burn so fiercely, but the impregnation of the covering.