KEY POINTS:
The lure of the perpetual motion machine has - like the car that runs on water - long captured the imagination of the dreaming classes.
Alongside such fantasies, local electricity distributor Vector was positively downbeat this week in starting trials of a personal household windmill which "could" provide a quarter or more of one's electricity needs.
It was almost as though their hearts weren't really in it. Only a quarter? If you're selling a dream, punters want it in technicolour.
I did have to wonder why a company in which I have a few modest shares would consider promoting something that could do them out of business, and me out of a dividend.
Then I read the small print and saw that Vector had an exclusive marketing deal with the turbine's British manufacturers. So there was money to be made whichever way the wind blows.
Maybe if I was living out in the sticks, the lust for a personal windpowered electricity generator might be more highly developed. But the thought of plonking a tower atop my suburban house and attaching a 2.1m diameter wind paddle to it at great expense, then praying for the wind to keep blowing in the hope of cutting my power bill a little, seems daft.
As I wrote a year ago when the former parliamentary Commissioner for the Environment waxed lyrical about the concept, why go all survivalist when you have the national grid? Surely one of the advantages of living in towns is that we don't have to till our own field or rub two sticks together to make fire.
Last month, Vector said it had bought a 19.99 per cent shareholding in NZ Windfarms. To me that's the sensible way to harvest wind energy - on a grand scale using giant windmills on a windswept hillside, out of sight and far away.
The idea of a whirlygig on the roof, pumping out power for nothing pushes all the right emotional buttons in this age of fossil-fuel phobia. But a quick search on the internet shows that even those who want these micro-wind generators to be a success have their doubts.
The maker of Vector's windmill claim it can pump out 2000 to 3000 kilowatt-hours a year or about a quarter of the average New Zealand household's needs.
But independent tests reported in the London Observer suggest these micro-turbines produce only 10 to 25 per cent of the output claimed.
The BBC's Justin "Ethical Man" Rowlatt, whose mission is "to live an ethical life", wanted a windmill but was told by the experts that the wind-power at his home on the highest hill in London was enough only to run a light bulb.
Of course if people have a spare $8000, plus whatever installation costs are, to dabble in such toys, why should the rest of us care? Well for one good reason. The effect their trendy status symbols will have on the rest of the community.
First, the visual pollution. It's all very fine to put one atop Waitakere City's new council building and pretend it can hardly be noticed. But imagine a forest of them atop suburban homes.
Anyway, the experts say that because of the turbulence caused by neighbouring roofs, these little windmills don't work very well at suburban roof level.
Ideally, says the British Wind Energy Association, they should be at least 10 times the height of your neighbour's roof, up "a very tall tower." Very tasteful.
But ugliness is not the only problem. We're assured the turbine in question, the Swift, is "virtually silent," emitting less than 35 decibels of noise while in action. Silent? The British Building Research Establishment says 35 decibels is the noise level heard through a single-glazed window in a busy suburban street.
Would you want to live next to that sort of silence day and night? And that's presumably the non-noise when it's brand new. I recall the squeaky weather vane next door when I was a kid. What happens when the bearings start rusting and the owner loses interest?
I'm all for saving the planet. But there must be an easier way.
