NextBillion - An Initiative of the William Davidson Institute at the University of Michigan

Thursday, July 18, 2013

There are plenty of scientists out there trying to solve our impending energy crisis. Many of their creations never leave the lab. Here’s one that is on its way to commercialization — and just fixed one of its biggest problems.

Veteran biochemist Daniel Nocera has been working for decades on an “artificial leaf” — a silicon wafer that can create energy from sunlight and water the way real leaves do. Nocera unveiled an early version of the leaf in 2011. This week he announced a much-improved version.

Here’s how the leaf works: you stick it in a quart of water, and it splits the hydrogen and oxygen. The hydrogen is collected and stored in a fuel cell. A single leaf in a quart of water can provide 100 watts of energy, 24 hours a day.

That’s just enough energy for the estimated 3 billion people in the world who lack dependable access to an electric grid. The problem with the old version of Nocera’s leaf, however, was that it required clean water — something else those billions lack dependable access to.

But Nocera’s new leaf will work in dirty water, too. It’s self-healing, meaning it prevents bacteria from forming a foothold on its surface.