Hydrogen Production from Solar Energy

Solar energy is potentially the most abundant renewable energy resource available to us and hydrogen production from solar energy is considered to be the ultimate solution for sustainable energy. The various methods for utilizing solar energy for hydrogen production are examined and both their advantages and disadvantages are compared. The technology of splitting water using solar energy can be divided into the four main topics: photochemical systems; semiconductor systems; photobiological systems; and hybrid and other systems. Concentrated solar energy can also be used for the direct decomposition of water to produce hydrogen. As a result of the great potential promised by solar energy technologies, low cost, high efficiency hydrogen production systems utilizing solar energy are the subject of intense investigation. The most common method of solar-based hydrogen production utilizes photovoltaic (PV) cells in combination with water electrolysis. In this system, PV cells are used to create electrical energy. An electrolyzer passes this electric current through water, causing the water molecules to separate into hydrogen and oxygen gases. Older electrolyzer designs are operated using water premixed with a caustic electrolyte, most often potassium hydroxide.