Magnesium fuel cells may displace hydrogen fuel cells if the problem of energy used to purify it can be overcome. Magnesium is a silvery metal that stores about ten times the amount of energy that hydrogen does, and the earth's seawater contains enough magnesium to meet the world's energy needs for 300,000 years.

Scientists around the world are working on magnesium fuel cell development and one of them thinks that a solar-powered laser might pack the punch needed to efficiently purify magnesium for use in fuel cells.