Hydro-electric power is what keeps most of Western civilization going. In recent times books have been written that say when the earth runs out of oil, people will have to turn to alternative methods for transportation, and that the hydrogen in water can supply all humanity’s transportation needs. We learn that in Vedic times, thousands of years ago, robots were powered by hydraulic energy. Obviously this was done using subtle energies not possible to access today. Hydrogen power is at present deemed to be outrageously expensive.