An overview of hydrogen gas production from solar energy

Hydrogen production plays a very important role in the development of hydrogen economy. Hydrogen gas production through solar energy which is abundant, clean and renewable is one of the promising hydrogen production approaches. This article overviews the available technologies for hydrogen generation using solar energy as main source. Photochemical, electrochemical and thermochemical processes for producing hydrogen with solar energy are analyzed from a technological environmental and economical point of view. It is concluded that developments of improved processes for hydrogen production via solar resource are likely to continue in order to reach competitive hydrogen production costs. Hybrid thermochemical processes where hydrocarbons are exclusively used as chemical reactants for the production of syngas and the concentrated solar radiation is used as a heat source represent one of the most promising alternatives: they combine conventional and renewable energy representing a proper transition towards a solar hydrogen economy.