light and easy

I've always been a big proponent/fan of renewable energy in general and solar power in particular. Hitherto i had always held the idealized belief that solar power is a never-ending and perpetual source of power with zero emissions and is 100% environmentally-friendly. But when i delved deeper into the subject today, i discovered that there may be a darker side to solar power as well as its obvious benefits. You see, currently a lot of solar power is produced by old-fashioned solar panels. The manufacturing of solar panels requires polysilicon, a material which is made from silicon. In the process of making polysilicon, a waste/by-product is produced, called silicon tetrachloride. Now silicon tetrachloride can be processed and recycled safely at high temperatures (1,800 degrees Fahrenheit) and put back into the production process. But this processing entails high investment costs and time. According to a Washington Post article dated March 9, 2008 by Ariana Enjung Cha, in China the problem is some companies that make polysilicon dump the waste/by-product silicon tetrachloride unprocessed in the factory's immediate surrounding countryside areas. Yep, just like that and easy as pie. Unprocessed silicon tetrachloride releases highly toxic and corrosive hydrochloric acid ("HCL" - remember secondary school chemistry class? yep the same stuff, old HCL) and generates fine powder silicon dioxide which is so fine that it can be easily ingested or inhaled. HCL is produced when silicon tetrachloride reacts with water in the soil. Crops cannot grow in this and it is certainly not suitable for people to live nearby. For each tonne of polysilicon produced, the process generates at least 4 tonnes of silicon tetrachloride liquid waste. And some Chinese companies manufacturing polysilicon have been dumping their unprocessed silicon tetrachloride wastes right outside their factories where there are rural communities living on and working the land. Crops die and the peasants complain but nothing is done except denials from the bosses and a promise from the local authorities to "look into the matter". Companies save a lot of money by not treating their silicon tetrachloride wastes. As you can imagine, the margin thins dramatically when you have to foot a huge electricity bill and additional manpower/time spent just to treat your waste/by-product. The solution? Just dump it.
In Malaysia we already have a solar power outfit "First Solar" operating a RM2 billion plant in Kulim, Kedah and it recently expanded its production lines there. Next to come to Malaysia, that is in Malacca where Yours Truly is domiciled, is another solar power outfit called Sun Power, a San Jose, California based company founded in 1985 (First Solar is also a US company). It's a given that they will be manufacturing solar panels which require polysilicon as raw material. Not a problem. Problem is when someone sets up a factory to produce polysilicon here and the aforementioned potentialities ala China, may then surface. If they are importing polysilicon say from China, we will not suffer the ill-effects of indiscriminate dumping of silicon tetrachloride here. I hope.

On a brighter note, there is new technology that doesn't require polysilicon, for example "Solar Paint" developed by Nanosolar (a solar power outfit also based in San Jose, California)and "Solar Ink". Popular Science magazine's Michael Moyer writes: "Imagine a solar panel without the panel. Just a coating, thin as a layer of paint that takes light and converts it to electricity. Popular Science's Innovation of the Year for 2007 is a solar cell that can be printed like paper and applied to roofs or any other flat surface, delivering solar energy at 1/10th the cost of a traditional glass and silicon cell."

One hopes that First Power and Sun Power will invest in Solar Paint/Solar Ink as well as producing traditional solar power panels. Woe betide us if anyone decides to make polysilicon in Malaysia, decides to save some money/increase profits the easy way and not process its waste/by-product silicon tetrachloride but just dumps it all in some kampung. Remember Asian Rare Earth's case in Bukit Merah, Perak during the 80s? I liked HCL better in the confines of my secondary school chemistry laboratory.