Monday, March 10, 2008

Even renewables may have their environmental downsides

As this article from the Washington Post highlights.

Polysilicon is a core component in any photovoltaic cell, and its manufacture is quite a toxic process, with one of the major by-products being silicon tetrachloride, an extremely noxious and poisonous chemical that is difficult to handle, and even more difficult to recycle back into the manufacturing process. The capital equipment costs simply to handle this one chemical is one of the main reasons why the production of polysilicon is so expensive in the Western world.

Now many manufacturers source their polysilicon from China. I hope, if they read this, they may think again.

See, by trying to manufacture as cheaply as possible, even something as green as a photovoltaic cell can be highly toxic to the environment.


Peter said...

Well, at least they have just decided they don't want our carrier bags any more. No more plastics going Chinawards!

Just a shame that they are not quite so diligent in other areas... or the numpties who seem keener to look green than actually concern themsleves with the full story, especially provenance chains.

An interesting insight from a plastics recycler just added to the Plastic Bags category. Not a big fan of most claimed eco-alternatives as they just poison the recovery chain.

I'm not encouraged. It's obvious that we need joined-up thinking across the board at high level, based on clear science and a commitment to the enviROI above any agendas or targets. But sadly froth, knee-jerk and spin are all we seem to be getting.

Jim's Words Music and Science said...

Thanks for highlighting this problem.

There is a solution (other than hoping the Chinese "do the right thing").

Recently-developed commercial products in the US use "solar paint" or "solar ink" to make solar panels without silicon. The materials are layered organic and inorganic devices. These extremely light weight and are very cost effective, making solar power now "cheaper than electricity from coal", it is claimed. However, these relatively small companies need to expand production capacity dramatically, and I think that they should get significant tax credit to do so.

For more details, see this blog entry on Nanosolar
and this collection of articles:

Best wishes! Jim