a word on domestic wind turbines …

From Real Goods, who’ve been doing the sustainability thing for almost 30 years:

We generally advise that a good year-round wind turbine site isn’t a place that you’d want to live. It takes average wind speeds of 8 to 9 mph [3.6-4 m/s, or 12.9-14.5 km/h] and up, to make a really good site. That’s honestly more wind than most folks are comfortable living with.

— Solar Living Sourcebook, 12th ed., p.80

you go, Glen!

Congratulations are due to Glen Estill, who got his two Vestas V82s on the Bruce Peninsula running today. Glen is a pioneer of wind energy in Ontario, and we’re all grateful to him for his tireless work for the industry.

Update: further to my wind turbines from space obsession, I found Glen’s original V80 turbine at 44° 56′ 46.42″ N, 81° 15′ 47.12″ W.

say something, anything …

It really annoys me that Natural Power Consultants have been so quiet about a blade failure at Crystal Rig. Not merely has it taken them two months to start repairs, but they haven’t come out with a news release saying what happened, how unlikely it is to happen again, and reassuring everyone that this is a) very unusual, and b) fully under control.

Wind farm operators aren’t alone. The actions of one in one country affects the industry worldwide. I mean, we’re even seeing questions in Ontario based on the Altamont experience. So, c’mon people, get hep.

Swift Turbine Specs Look Dubious

“Oh no, not again!” I’m saying to myself, and really hoping that — just once — I’ve done my sums wrong.

You’ve seen my rant about how the initial public specification of the WindSave rooftop wind turbine was an impossibility (and, in fairness to them, how the corrected specs are much more like the thing). And you may have seen that I’ve written about the Swift before. But the Renewable Devices Swift was all over the blogosphere (a hateful word, I must say) today; both Treehugger and sustainablog were on it.

So I download the very pretty PDF spec sheet. Here’s the technical table from the document, which is dated 19 November 2004:
swift wind turbine spec, from document dated 2004/11/19
So that’s a diameter of 2m, rated wind speed of 10.5ms-1, and a rated power of 1.5kW. Plugging that into my simplified Cp equation

Cp = P / ( 0.48106 d2 v3 )

which gives:

Cp = 1500 / ( 0.48106 × 22 × 10.53 ) = 0.67

As this is higher than the Betz Limit of 0.59, the claimed power output of the Swift wind turbine is theoretically impossible.

I don’t know how to put this, but rooftops are sheltered places; if they get any wind at all, it tends to be turbulent and highly directional. You get huge updrafts, none of which help generate power. I know of some very open sites that struggle to get the 3.5ms-1 cut-in speed of the Swift, and that speed is at 50m+, not on a rooftop.

Renewable energy, for me, is about using the appropriate technology for the right location. Devices like the Swift are a distraction from the whole conservation/renewables agenda.

big, real big

RePower 5M
RePower have installed the world’s largest wind turbine, the 5MW RePower 5M. With blades 126m in diameter on a 100-120m tower, this isn’t for the home scale wind enthusiast.

Their site’s incredibly slow just now, as it has just been discovered by SlashDot …

The Cyborg’s Windmill

Steve Mann's Wind Turbine
We spent the day helping wearable computing guru Steve Mann put a wind turbine on top of his Existential Technologies Research Lab (a.k.a. 330 Dundas St. West), smack-dab downtown in Toronto.

We installed a True North Power Lakota turbine. We had David Cooke and Doug of TNP guiding us, and the installation went without a hitch.

The picture above links to more pictures of the day’s activities. There are also Steve Mann’s Urbine pictures (and, if you really want bigger versions of my pictures, they are on scruss at eyetap).

Yet another Scottish rooftop turbine

Anent the WindSave turbine, yet another similar product has appeared: the Renewable Devices Swift. It’s Scottish too, and again there are few details. The Scotsman has the story.

Someone commented here that one could build such a device cheaply from parts from any DIY store. This isn’t quite the case. Properly formed blade sets are not trivial to make, and while you could build your own generator, weatherproofing it and making it CE-compliant would be hard.

learning about wind turbines

If you want to learn about wind energy, you might want to visit the Danish Wind Energy Association, the British Wind Energy Association, the American Wind Energy Association, the Centre for Alternative Technology, or the Canadian Wind Energy Association. All these folks have been proposing and living energy generation solutions for years.

wind-farm.org, however, is a hilarious mess of nonsense. It has been put together by a very few antis who managed to scrape up hosting and a CMS package. They also use that Never doubt that a small group of thoughtful, committed citizens can change the world… Margaret Mead quote that coincidentally appears on many pro-renewables sites. I’m half tempted to post to the forums under an assumed name, but I’m minded what Big Fred N. said: Battle Ye Not With Monsters, Lest Ye Become A Monster.