Challenging silicon's grip on solar

[OKIsItJustMe]

http://media.cleantech.com/2418/jin-zhang-and-solar-cells

Challenging silicon's grip on solar

February 6, 2008 - Exclusive
By Massie Santos Ballon, cleantech.com

A nanotech researcher recently thrust into the limelight gives us a tour of his lab.

Jin Zhang, a chemistry professor who works with nanomaterials at the University of California Santa Cruz, didn't expect the attention his lab's most recent publication garnered.

Within two days of a university announcement of his new nanotech solar innovation, the story was on 80 websites, and Zhang was fielding calls from around the world.

"The Internet spreads news faster, and to more people," he commented, pondering a call from China at 2 a.m. in the morning and a man from Israel who called and talked to the scientist for three hours.

...

Zhang skipped lunch to speak with Cleantech.com in his office about the efficiency of his new method, solar's interest in nanotechnology and how academia and investors can work together to make the work commercially viable.

...

[DCKit]

1. You always find the best stuff.

How are NanoSolar et al doing in bringing to market their $1.50/watt thin film solar? As far as I know, prices have been relatively stable over the past eight years, despite there being two or three announcements each year that affordable production is beginning on product-x in the next six months.

[OKIsItJustMe]

6. It takes some gleaning

There's a great deal of chaff, but I can usually find a grain or two of wheat.

[Dogmudgeon]

2. But the change will be toward cadmium

Most of the new photovaltaic technologies depend on exotic cadmium-based alloys.

If you thought plutonium was bad, wait until you see what cadmium can do!

We should strongly support basic research in these technologies, but the actual industrial-strength building of solar energy should be centered on "heliothermal". Yet it's not nearly as "sexy" from an investment point of view, and only Abengoa/Solucar appears ready to install capacity. (And they're Bechtel affiliates.)

The Internet and Nanotechnology -- they're sexy, as you can see in the article. Someday, these technologies may reach commercial potential, but not any time soon. While scientists and engineers continue their work, there are a dozen genera of technology that we can work on to provide mass-scale power.

--p!

[DCKit]

3. It is my understanding that the risk is confined to the manufacturing process.

The cadmium (a fraction of what's in a NiCad AA cell for each full panel) is said to be chemically locked with the other materials on the panel.

I'm no fan of Cadmium, but like any other toxic or dangerous element that's contained in different molecule with others (Na + Cl = salt), the risk and toxicity are lessened or eliminated.

That's what I've heard. I'll wait until there's more information before running out to buy any solar panel containing Cadmium.

[Dogmudgeon]

4. Cadmium is dangerous in nearly all of its forms

Different forms may vary, but they are almost all highly toxic. And the most common stable forms and breakdown by-products are the most highly toxic.

Well-manufactured materials pose very little risk. The risk is in the waste products of the manufacturing process, as you noted, and disposing of the products, in this case, solar cells. A few years' exposure to the elements, and a significant hazard could be created.

That is why I am a much stronger proponent of heliothemal (it sounds cooler than "solar thermal", dunnit?) power. It is much lower-tech and has a higher energy yield. It would be easier to bring to the marketplace.

Some of the articles I see would have us believe that by 2014, we will be able to buy a 10 kWH solar panel array from Home Depot for $495 and install it with hand tools. Useful solar energy is a lot further off than that. Even with heliothemal technology, it's going to require a major effort in a short period of time.

--p!

[jpak]

8. Environmental and safety issues associated with CdTe modules are insignifcant

http://www.pv.bnl.gov/art_164.pdf

SUMMARY

As CdTe PV modules reached commercialization, vocal opposition emerged based on concerns about potential emissions of cadmium from them. In this short article I discuss the pertinent technical issues and conclude that CdTe PV modules do not present any risks to health and the environment during their use, and recycling the modules at the end of their useful life completely resolves any environmental issues.

<more>

and much more here

http://www.nrel.gov/docs/legosti/fy98/24057.pdf

[OKIsItJustMe]

5. Not in this case at least (titanium and zinc oxides)

...

There are two general methods for making solar cells using nanostructures: thin films of titanium oxide (TiO₂) or zinc oxide (ZnO) doped with nitrogen, or quantum dot solar cells. Zhang's lab found that combining these two methods to produce thin films of metal oxide doped with nitrogen along with quantum dots increases the solar conversion by a factor greater than sum of the separate processes.

...

[jpak]

7. No it is not.

CdTe PV is a small niche within the much larger PV market.

CIS PV, thin-film Si PV and concentrating solar-thermal electric are (and will be) the big players in solar energy (along with plain old solar thermal for domestic hot water).

nice try though...