Although I am not qualified to judge how realistic this plan is from a scientific or business standpoint, this detailed description of a potential method for obtaining energy from magnesium in seawater using lasers powered by the sun is both fascinating from a science & technology perspective and inspiring from a human perspective. Maybe, just maybe, we can think of technological ways to unscrew our species and this planet before it's too late. Five G2 class stars out of five!
I'm not sure if an English translation is in the works or not, but there is an English Web site for anyone who's interested: