Consider a giant sponge, with limbs and tentacles that reach to the horizon. It dips into distant rivers, it delves for deep waters, it digs ditches to catch the rain—all to slake its insatiable thirst.
Clearly, this is no ordinary sea creature quietly snuffling the currents. We have met this sponge, and it is us. We humans are the thirstiest of creatures, and we’ve developed a nearly insatiable taste for this simple but delectable arrangement of hydrogen and oxygen atoms. But we need more. So much more.
We’re not talking about just drinking or bathing. Without water, we’d have practically no energy. Without energy—and therefore cars, planes, laptops, smartphones, and lighting—we wouldn’t be doing much.
In almost every type of power plant, water is a major hidden cost. Water cools the blistering steam of thermal plants and allows hydroelectric turbines to churn. It brings biofuel crops from the ground and geothermal energy from the depths of the Earth. Our power sources would be impotent without water.
Don’t believe us? Plug your iPhone into the wall, and about half a liter of water must flow through kilometers of pipes, pumps, and the heat exchangers of a power plant. That’s a lot of money and machinery just so you can get a 6–watt-hour charge for your flashy little phone. Now, add up all the half-liters of water used to generate the roughly 17 billion megawatt-hours that the world will burn through this year. Trust us, it’s a lot of water. In the United States alone, on just one average day, more than 500 billion liters of freshwater travel through the country’s power plants—more than twice what flows through the Nile.