Photos: Green innovations from the 'Stonehenge of Silicon Valley'

The mouse, the PC, Ethernet, and a lot of printer technology came out of the 'Stonehenge of Silicon Valley,' the Palo Alto Research Center. Once part of printing company Xerox's research team, the now-independent research business comes up with innovations and then tries to commercialise them, and its latest ideas are in solar tech and water purification.

Roughly half of PARC's revenue still comes from contracts with Xerox, but work with third parties is expanding. It developed mini-solar concentrators (above) with rapidly growing solar concentrator company SolFocus, which will adopt them for its next generation of concentrators. They've been reduced in size to 2.5cm across, down from the standard 15cm. At the smaller size they can be made on a single substrate, cutting down on cost.

Another solar innovation out of PARC is its printed solar contacts (the wires that shuttle power from the solar cell to your home), which are much thinner than ordinary ones (below). This means fewer shadows on the solar cell and, therefore, more power. The contacts aren't on the market yet, but the company is working with the solar industry to commercialise them.

But perhaps more groundbreaking is PARC's water purifier (bottom). Water is funnelled through a spiral channel at a high rate of speed, and the rotational force of the water pushes floating particulates and biological matter to form a stream within the stream of water. The matter stream is then ejected and you get purified water.

The purification system, PARC theorises, could be superior to membrane purification systems because there is no membrane to get clogged up. Clogging is a major problem with conventional systems.

On the left and in the background you have a conventional solar cell. On the right and in the foreground is a solar cell with contacts. (Photo: PARC)

PARC's water purifier (Photo: PARC)