From toothpaste to solar energy
By Abigail Klein-Leichman January 13, 2009
While searching for an ingredient to make toothpaste flow more easily, an Israeli chemist came across a novel way to produce inexpensive, clean solar energy. 3GSolar, the company born of that serendipitous discovery, is now poised to light up the developing world.
"There are maybe a billion and a half people living without electricity," Dr. Jonathan Goldstein, the British-born inventor and battery scientist who founded 3GSolar in Jerusalem in 2003. "Many governments of developing countries are keen on bringing people forward to improve their living standards."
Goldstein's deceptively simple solution is set to revolutionize dye-sensitized solar cell (DSC) technology, invented in 1988 by Swiss scientist Michael Graetzel. The cells are photovoltaic (PV), meaning they convert radiant energy - such as sunlight -- into electricity with the help of a layer of semiconductor.
"As a battery scientist, I saw why nothing commercial had come out of the invention: Cells were tiny and nobody knew how to scale them up to be something practical," Goldstein tells ISRAEL21c.
He knew that if he were able to make a larger DSC, it could be a cheaper and more available alternative to silicon, the relatively expensive and scarce semiconductor currently used in most solar-energy panels. Silicon solar panels are also costly to produce.
Here's where the toothpaste tinkering came in handy. Goldstein had invented a toothbrush with toothpaste preloaded in its handle. In looking for ways to ease the flow of paste to brush, he learned about a cheap white powder called titanium dioxide - and discovered that it not only solved his toothpaste problem but also had a track record in DSC technology. If treated with an absorbable dye, titanium dioxide becomes sensitive to light.
"You can easily screen-print thin layers of titanium dioxide on surfaces and churn out plates of this material and then oven-bake the layer on firmly - it can even be baked on in the air, with no need for expensive equipment," he explains.
Extracting generated current
Goldstein's low-cost current collector enabled building tablemat-sized cells and extracting the generated current.
Initially, 3G was funded by an Israeli government incubator program. In its second year, it caught the attention of New York-based venture-capital fund 21 Ventures. With a staff of 18 scientists working on the project, the concept quickly took shape.
"We're on schedule for pilot production in early 2009, with initial plant production in Israel in 2010," says Goldstein, adding that 3GSolar is on track to be the first PV manufacturer in Israel. It is also soon to become the first Israeli company on the Toronto stock exchange.
Government officials in Senegal and India are eagerly awaiting the first panels. "There is a lot of interest because PV is clean energy and it's always there on the roof if you get a blackout," says Goldstein. "People like to have that security."
He has an ambitious yet prudent business plan. "We will build ourselves up slowly within those [developing] markets and then move to industrialized countries in our second generation," he says. "These countries may buy just one or two panels per family -- not for air conditioning, but for the basic needs of someone who might have electric light in his home for the first time."
The glass-based titanium-dioxide-treated panels are expected to debut at half the cost of similarly sized silicon panels. "We believe as we make more plants, that will drive our cost down even more," says Goldstein.
He envisions maintaining a plant, and R&D facility in Israel, as well as licensing the technology to countries that will be using the panels. "The manufacturing plants can be put in anywhere because all you need is a screen-printing machine and some sort of oven," he explains.