Desalination takes a surprising amount of energy, but in California many communities are actually using just as much energy to pump fresh water to where it’s needed.
John Lienhard, a professor of water and food at MIT, offered a potentially better solution at our EmTech conference this morning. Like so much in energy efficiency, it’s a hybrid approach. He suggests building a system that involves both pumping and desalination.
Desalinating enough seawater to fill 1,000 one-liter bottles consumes the same amount of energy as running a microwave continuously for three hours. Even in theory, the minimum amount of energy you need would still require the equivalent of running a microwave for an hour (see “A Cheaper Way to Clean Water” and “How Carbon Wonder-Materials Are Promising to Revolutionize Desalination”).
The only way to use less energy than that, Lienhard says, is to find less salty water, also known as brackish water. And it so happens that many places have vast underground reservoirs of it. Texas, for example, which consumes a few million acre feet of water per year, has 2.7 billion acre-feet of brackish water. Why wait for breakthroughs in materials to make desalination widely affordable? Instead, pump that brackish water a relatively short distance to the surface and then desalinate it. In many places this might slash energy use and make desalination more affordable.
10 Breakthrough Technologies 2024
Every year, we look for promising technologies poised to have a real impact on the world. Here are the advances that we think matter most right now.
The worst technology failures of 2023
The Titan submersible, lab-grown chicken, and GM’s wayward Cruise robotaxis made our annual list of the worst in tech.
AI for everything: 10 Breakthrough Technologies 2024
Generative AI tools like ChatGPT reached mass adoption in record time, and reset the course of an entire industry.
Scientists are finding signals of long covid in blood. They could lead to new treatments.
Faults in a certain part of the immune system might be at the root of some long covid cases, new research suggests.
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.