A number of solutions to this challenge already exist, but they still need to be put into practice. If the wind or the sun produces more electricity than is needed at a given time, then one solution is to store it mechanically – by using it to pump water upwards or to compress a gas, for example. Later, when the electricity is needed, the stored energy can be used to drive a turbine.
Another interesting possibility is to use excess solar or wind electricity to split water molecules and produce hydrogen gas. Hydrogen can either be used as a fuel or processed to produce methane. It is also a very green and efficient way of generating electricity in a fuel cell. Other solutions are also on the horizon: Helmholtz researchers, for instance, are working on new kinds of solar cells that combine different types of photovoltaic technologies and can directly convert sunlight into hydrogen.
This question was answered by Dr Antonia Rötger, science writer in the communication department of the Helmholtz-Zentrum Berlin für Materialien und Energie.