Renewable hydrogen produced using solar energy to split water is the energy fuel of the future. Accelerated innovation in both major domains of solar energy (photovoltaics and concentrated solar power) has resulted in the rapid fall of the solar electricity price, opening the route to a number of practical applications using solar H2.
New thermochemical water splitting using concentrated solar power (CSP) as well as CSP coupled to electrolysis has the potential to convert and store solar energy into clean hydrogen using a tiny fraction of the world’s desert area to meet our present and future global energy needs. Photovoltaics, in turn, has the versatility required for supporting the creation of a distributed energy generation infrastructure in developing countries especially now that the price of PV solar electricity has fallen to unprecedented low levels. In all these cases, solar H2 will be used to store energy and release it on demand either for fuel cells (to power homes and boats) or internal combustion engines and turbines (for powering cars, trucks and in thermoelectric power units). Referring to several examples as well as to new technologies, this article provides insight into a crucial technology for our common future.