Storage facilities are a must if Switzerland is to cover its electricity needs using renewable energies such as solar energy, yet conventional storage systems such as batteries are not sufficiently mature for this task. Moreover, they contain environmentally harmful and rare materials, and are too bulky.
Fortunately, the sun's energy can also be stowed in the form of liquid hydrogen, which stores a high energy density, is easy to transport and can compete with the price of conventional fuels. Hydrogen could be traded at five euros per kilogram, while producing the same amount of energy as four litres of crude oil, traded at eight US dollars in 2013.
The solar-to-fuel method
This method consists in using solar energy to split water molecules (H2O) ) into their components oxygen (O) and hydrogen (H2). The hydrogen thus becomes the energy carrier. One kilogram contains the same amount of energy as 2.8 kilograms of petrol. Hydrogen can be burned in a fuel cell at any given time, rain or shine.