Solar-Powered Laser

"A new kind of efficient, solar-powered laser has been developed by researchers at the Tokyo Institute of Technology, in Japan. They hope to use the laser to help them realize their goal of developing a magnesium combustion engine (...) The idea (...) is to make a powerful laser capable of combusting the magnesium content of seawater. In the process, large amounts of heat and hydrogen are given off. Magnesium has great potential as an energy source because it has an energy storage density about 10 times higher than that of hydrogen, says Yabe. It is also highly abundant, with about 1.3 grams found in every liter of seawater, or about 1,800 trillion metric tons in our oceans, he says (...)"

Source: http://www.technologyreview.com/Energy/19402/