The problem is that copious amounts of water are used in creating most every type of energy. Plus, energy is used to pump the water to the power plants to create energy. But water is becoming scarce.
IEEE has a comprehensive mini-website with detailed articles on the coming conflict between water and energy.
The era of easy energy and plentiful water is ending; a new way of husbanding these resources must begin. Two islands stand out as compelling test cases. In Malta, a smart grid will monitor both water and electricity to elucidate the connections between the two. And Singaporeans have learned to accept the fact that their urine—treated and cleaned up, of course—is now part of what emerges from the tap.
Are these the kinds of solutions we need to keep the human machine and all its thirsty tentacles sated? We think they’re a start. How we plan—or fail—to resolve the competition between water and energy needs will become one of the defining issues of this century.