This book covers how magnesium can be used for metal-air-fuel cells for automobiles and powerplants. The automobile with Zinc-air-fuel cell achieved 600km mileage in 2003 and Magnesium-air-fuel cell can give 3 times more energy which is 7.5 times more effective than Lithium-ion battery. Solar-pumped laser regenerates metal Magnesium from combusted Magnesium oxide. The book covers how low-cost desalination with solar-power will be a promising solution to the global water shortage.