Tuesday, March 1, 2005

Breakthrough in solar photovoltaics

In the quest for cleanly produced power, photovoltaics (a.k.a. solar panels) are one of the primo sources. However the issue that has dogged every "alternate" electric power generating system is the cost. Thems that makes the rules (because thems are the ones with the gold) have proclaimed that an alternate electric power generation must cost competitively with the existing power generation systems.

This situation creates a "moat" around existing power generation systems, making for a very tough hurdle to jump. For nearly any product to become "cheap", the rules of mass market capitalism says that the product must achieve mass production. But to achieve mass production it has to be selling pretty well in the market, and it won't sell well in the market if people aren't buying the product because it's more expensive than the existing technology.

The rule of thumb I've heard several times is that an alternate electric power generation system must cost under $.05 per kilowatt hour of capacity.

Breakthrough in solar photovoltaics

THE HOLY Grail of researchers in the field of solar photovoltaic (SPV) electricity is to generate it at a lower cost than that of grid electricity. The goal now seems to be within reach.

A Palo Alto (California ) start-up, named Nanosolar Inc., founded in 2002, claims that it has developed a commercial scale technology that can deliver solar electricity at 5 cents per kilowatt-hour.

The company in question is
Nanosolar, Inc.

The technology is interesting, and has these salient points:

  • Thin film: Many solar panel companies use thin-film technology, and strangely Nanosolar doesn't mention them in the discussion of their competitive stance. Thin film allows for flexible solar panels that use less materials to produce.
  • Roll-to-roll based printed production: On their web site they show a machine with rollers processing sheets of plastic. This makes it easier to produce the panels.
  • Nanotechnology to produce the photovoltaic surface

Traditional solar panel production works similar to the way semiconductor chips are made. It involves producing silicon wafers, cutting them into slices, and assembling them into panels. Comparitively the roll-roll technology allows the panels to simply roll out of a machine.

But, the technology isn't as unique as Nanosolar makes it out to be. Namely Uni-Solar has been using this combination of technology for a very long time.

What makes Nanosolar different from Uni-Solar is the nanotechnology. But they don't say much about it on their web site.

UPDATE (March 17, 2005)) A commenter says he understood Nanosolar's special technology is the ability to construct several layers, each reactive to different light frequencies. This is what I would assume they are doing, but I am by no means an expert, merely an interested bystander. What I understand is the traditional solar panel technology is dependant on crystal silicon. It is the size of gaps between atoms in the crystal matrix that determines which light frequency the panel is reactive to. With a pure crystal all the atoms in the crystalline grid are at the same distance apart, so traditional solar panels can react to only a narrow band of light frequencies. To increase the absorption power it's required to use a crystal matrix where the inter-atomic gaps vary. For example the Ovonics approach is to use an "amorphous" semiconductor, where the crystal has two or more elements in it, and the differing elements results in an uneven gap-size in the crystalline grid. This makes an Ovonics solar panel react to a wider range of light and have higher frequencies. Similarly if a panel were made of several layers, each reacting to a different light frequency, it would have a similar effect. I think.