One of the most important alternative sources of energy is photovoltaics. Solar energy, growing everywhere (especially in China) is available in abundance and 100% renewable.
The problem that has always plagued solar energy researchers is not about its availability and renewability, but the possibility of storing it for a long time in a battery. This has so far prevented it from being used for long-term solutions.
A research team from Chalmers University of Technology in Gothenburg, Sweden has developed a special type of fuel able to harness and conserve the sun's energy for up to 18 years. It has taken almost a year to develop and is now providing the first extraordinary results: they called it solar thermal fuel.
In short words? Solar gasoline.
What is it?
Fuel is essentially a liquid version molecule that "traps" thesolar power to use it later. Its main components are hydrogen and nitrogen: when heated, the molecules change density and act as accumulators of a battery conserving the energy collected.
The peculiarity is that upon subsequent cooling (up to room temperature) the fuel molecules continue to hold the solar energy tightly, transforming into isomers.
Whenever it is necessary to dispose of the stored energy, the fuel is passed through a simple catalyst capable of converting it into its original form and making it available for use.
A sort of non-corrosive “liquid for batteries”, a carrier that once “discharged” after passing through the catalyst can be recycled immediately. Nothing is burned like traditional fuels.
It seems to me an absolutely brilliant and extraordinary thing.

The development of “solar petrol” is still in the experimental phase. The first results (which have been astounding) have so far been obtained in the laboratory.