Renewable energy sources like wind, sun, biogas, hydropower and geothermal energy are becoming increasingly important for meeting the world's energy needs. Hydrogen plays a role as energy storage in this development.
Not only is hydrogen an environmentally friendly source of energy, it is also suitable as a storage medium – i.e. for energy produced from regenerative sources such as sun or wind. These are subject to natural fluctuation: the wind does not always blow – let alone always evenly or strongly – and the sun only shines during the day and only intensively enough in the temperate zones.
To ensure reliable power supply, solar and wind energy must thus be stored so that they are available when needed. Hydrogen plays a significant role in this process. Through the electrolysis of water using energy generated from wind or sun, hydrogen can be produced and compressed, or left in liquid form, as long as necessary. If energy stored in this form is needed, the hydrogen can be combusted into electricity and heat with no emissions – or with the aid of fuel cells, reconverting it into electricity. Hybrid power plants that use wind power and hydrogen to generate and store energy are already completing their first trials.
