Monday, July 04, 2005

Cheap solar power?

Bill Gross of Idealab has a new company called Energy Innovations, which is introducing an innovative solar generator called the sunflower. Their generator is a "concentrator" which uses mirrors to focus direct sunlight onto a stationary photovoltaic cell (PVC). Since the PVC is the most expensive component of a solar generator, this makes good economic sense if the mirror array is cheap and robust. Gross and company claim to have solved this problem, using cheap microprocessors and a custom bearing array with only two motors. The sunflowers are built in China and are designed to fit in a shipping container. Gross claims that businesses with flat roofs in states like AZ or CA can pay for the machines in only 3-5 years from electricity savings! (Compare to 20 years for ordinary flat solar panels.)


Anonymous said...

Do they have an innovative way to clean the mirrors?

That collector post would be a great place for birds to sit (at night at least).

Steve Hsu said...

I think the PVC part gets very hot, so birds might avoid it during the day.

There are a number of long-term maintenance issues, like cleaning the mirrors, readjusting in case of high winds, etc.

I think it may still be workable if, say, a building owner installs a large number of these on a rooftop and pays for regular maintenance using economies of scale. Perhaps you just need to hose off the machine every few nights. The PVC has an IP connection, so you could monitor the function of a big array pretty easily from afar.

It's early days for this kind of thing, but it appears Gross and company have made some good innovations. They started thinking about the economics and engineering issues right from the start.

Anonymous said...

I am not an engineer, could a magnifying glass be used as opposed to many mirrors bouncing light back up? Once again creating the focal point, much simpler and easier.

Manu Sharma said...

They used lens too but it proved to be more expensive.

From their FAQs

One of our prototypes, the SunPod, used a Fresnel lens to concentrate light onto PV cells. It was highly effective, but the cost of Fresnel lenses was too great to deliver a market-competitive product.

Anonymous said...


I think that this is a good start
for the idia of a technology that
can be improved with an excellent
promising future. Because if we caa
use the sun as a source of energy
for a cleaner and healthier invi-
ronment why not use it. and by the
way the intire earth will thank to
those innovative people

Anonymous said...

It's a great innovation of producing cheap solar power, because it is essentially infinite, so it never runs out, unlike fossil fuels. The amount of solar energy intercepted by the Earth every minute is greater than the amount of energy the world uses in fossil fuels each year. And people can get huge profit by using solar power.

Anonymous said...

The hotter a PVC gets the less power it produces.

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