A recent report by NanoMarkets suggests that the growth rate of thin film solar pv, will continue to outshine the rest of the solar sector. They predict that the thin-film photovoltaics (TFPV) market will produce the equivalent of 26 gigawatts (GW) by 2015 and will generate well over $20 billion in revenues in that same time frame. What's particularly interesting is that the report points to cadmium telluride as being the fastest growing part of this niche and will be the largest part of this niche - with $8.7 billion in sales.

A few years ago, I was pretty dubious about the prospects for thin-film. Ok, it cost less, was flexible, often expensive polysilicon-lite or free, less weighty and easier to install. On the other hand, it worked at lower efficiency, typically half, so you'd need to buy twice as much of the stuff by surface area to get the same power output, which in my books made it a non-solution. Still, all of those factors can't be decisive if it continues to grow so fast.

Having said that, if I was to put my sceptical hat on, the thin-film report writing business seems to be a very popular one right now - shades of the fuel cell report business in the late 90s or even the mobile phone WAP business technology market that somehow never, ever, appeared. This report published last month by EUPD Research concluded that " . . . less than 50 percent of the 60 companies that have announced their intention to start commercial thin film production by 2010 will keep the timeline".

And they have a point. As with any forecast, the further it goes out into the future, the more likely it is to be wrong.  Both demand and the pace of technological change are slippery customers. That's why one can justifiably have more confidence as a cautious investor in the near forecasts, out to 2 years, than the longer ones, 2- 10 years.