Can Sun and Wind Make More Salt Water Drinkable?
Here are four arid regions looking to renewables for the energy-intensive work of squeezing drinkable water from the ocean.
The oceans have long taunted those who thirst.
Records dating to A.D. 200 show that sailors boiled seawater and used sponges to absorb fresh water from the steam. Today, desalination is more sophisticated: multistage flash distillation, reverse osmosis, electrodialysis, and more.
But one thing hasn't changed since the time of the ancient mariners: It takes a lot of energy to squeeze drinkable water from salt water. So even though more than 70 percent of the Earth's surface is covered with water, civilization has quenched its thirst mainly by tapping the one percent of world water that is unfrozen and fresh.
The one notable exception: Oil-rich Saudi Arabia and neighboring arid nations have used their wealth to purify ocean water. Yet their water demand