I’ve always been curious about vertical-axis wind turbines, or VAWTs, which haven’t received much attention in the wind-energy market because of failed attempts in the past to commercialize them. The smaller versions are generally designed for rooftop use on high- or low-rise office buildings, apartment complexes and homes, but they can be made much larger for use in a wind-farm model.

Many of the companies selling these products — assuming they have product for sale — are either small private companies or publicly traded over the counter. Lacking credibility or a track record, and often failing to provide adquate information on their products, these companies tend to be dismissed and eventually they fade away after trials and tests fail to result in sales. It doesn’t help that many wind experts dismiss the technology as experimental, unproven or disproven after two decades of government testing.

That said, I do think there are many home and building owners in cities who would be curious about the use of small vertical-axis turbines in an urban context, given the fact these products require less space than traditional turbines and are touted as less noisy. 

This is why I was pleased to see that McMaster University in Hamilton, Ontario, is evaluating a 2.5 kilowatt vertical-axis wind turbine from Cleanfield Energy Corp. of Mississauga. The turbine is designed for residential and commercial use, helping homeowners and businesses offset their energy use with wind power without needing the height and pole required for traditional turbines. McMaster’s department of mechanical engineering is studying the performance of the Cleanfield Energy turbine in urban wind conditions.

There’s a vertical-axis turbine from another company called Windaus Energy Inc. in Brantford, Ontario, that McMaster would also be wise to test out. Ditto for a much larger VAWT system from Calgary-based Sustainable Energy Technologies Corp., which is publicly traded on the TSX Venture Exchange. Heck, if you’re going to test one might as well test a few for comparison.

I will be very curious to see the result of the university’s study, given the lack of information about these intriguing but equally suspicious wind-power products. For an interesting history and update on vertical-axis wind turbines check out this June 2004 article in Mechanical Engineering magazine. It’s quite optimistic about the prospects for VAWT systems.

Perhaps this is just a case of good technology, bad marketing. BTW: I welcome any comments from people who have some experience with VAWT systems.

Silicon shortages may be slowing down the growth of solar PV sales in the United States, but this doesn’t make the growth that has happened any less spectacular. The U.S. Department of Energy reports that 2004 shipments were up 65 per cent, while there was a five-fold increase in imports of modules and cells. Of interest is that the proportion of shipments of thin-film technology jumped from 6 per cent in 2002 to 12 per cent in 2004 — and growing.

It will be interesting to see 2005 figures to get a true sense of how the silicon shortages have affected supply.

(UPDATE: Click here to get some figures on the Chinese solar market, which includes associated figures on silicon production.)