The Israelis are building ONE solar energy plant that will supply 5% of their energy needs.

And then there's this from the boys at MIT....

July 31, 2008 11:00 AM PDT
MIT researchers split water to store solar energy
Posted by Martin LaMonica

The key to plentiful solar power is water, says Massachusetts Institute of Technology Professor Daniel Nocera.

Nocera and his MIT colleague, Matthew Kanan, on Thursday will publish a technical paper that describes what they claim is a breakthrough in solar energy storage.


The key to MIT's discovery is a catalyst made from abundant materials that can make oxygen gas by passing an electrical current through water more effectively than previous methods.

(Credit: MIT)The idea is to use the energy from solar photovoltaic panels (or another electricity source) to crack water molecules into hydrogen and oxygen gas. Those gases would be stored and used later in a fuel cell to make electricity when the sun is not shining.

The concept is a closed-loop system: running the hydrogen and water through the fuel cell creates water, which can be captured and used again.

The hope is that within 10 years, a cost-effective system that combines clean energy generation with storage can be engineered and available cheaply to people around the world.

"I'm open-sourcing this to let everybody run with it," he said. "My plan is that when people see it, they'll see it's easy to do and they'll start working it."

Artificial photosynthesis
The core scientific discovery was finding a way to break oxygen out of the water with a relatively inexpensive and benign material, Nocera said. The catalyst--made of a cobalt phosphate--can operate in plain water at atmospheric pressure, giving it more potential than existing methods, he said.

Commercially available electrolyzers already split hydrogen atoms from water. A hydrogen filling station, for example, could use an electric-powered electrolyzer to break off hydrogen from water.

A finished system that MIT researchers envision would separate both hydrogen and oxygen. Once stored, both gases would be fed into a fuel cell using a second catalyst like platinum to make electricity.

John Turner, a research fellow in photoelectric chemistry at the National Renewable Energy Laboratories (NREL), called the work a "significant result."

MIT researchers split water to store solar energy | Green Tech - CNET News.com