Wind Turbines

Some Estimates

Windmills or Wind Turbines are showing up all over Bruce and Huron County and down toward Orangeville.  Our area is the home of many naturalists and also people who work at what we've come to call "Hydro" or Ontario Power Generation which runs a nuclear power plant near us.

From naturalists I've heard that the turbines hurt birds on their natural flyway up the Bruce and from Hydro people I hear that they are a drop in the ocean for power production even though their company allows them to 'hook' to the grid..  Let's leave the power generation alone for a while.

Naturalists have quoted to me that Wind Turbines account for 800,000 to 1,900,000 bird deaths per year.  I don't know what the correct figure is, but I know that those numbers are not accurate.  When somebody quotes me a range that the high number is more than double the low number, I know they have not done their homework.  If they really had a good estimate it would be in terms of some number ... let's say like 1,200,000 plus or minus 10,000.  I'll make some estimates too, but not that far off.

Some people also quote the speed of the turbines at their tip.  One  friend used about 160 miles per hour at the tip.  That conjures up a race car image careening around a NASCAR track to me at least.  How could a poor bird avoid the blades?  A huge circular saw is envisioned.  The better question is what do we see with our eyes?

If you look at the Turbines along Highway 21, they seem to be going at a modest pace don't they?  Now let me give you an analogy.  Remember when kids actually would skate for fun on ponds like Fairy Lake? We've all played 'crack the whip' as kids.  As soon as we learned that it's better to be at the centre of the whip and not on the end, we learned an important lesson in physics.  An unsuspecting child could be hurled across the pond in an instant.

If you are the last person out on the end, then you are apt to be tossed across the ice and take a terrible fall or risk being called a chicken for letting go quickly, but if you are on the other end, you are hardly moving and can smile at the inexperienced kid at the end.  In any event, the slowest skater could avoid that whip like action of the kids quite easily and so can birds avoid the turning of the blades, if they are not going at warp speed and they are aware of the flashing light at the top.

Some of the early placement of these turbines caused trouble, but with new designs and warning lights, they seem to be quite safe for the birds.  It's very difficult to do a real study so antidotal information abounds.  For example, I read one study which estimates the number of Wind Turbines in the world and then assigns two bird deaths per year to each and comes up with about 1,400,000 bird deaths per year due to collisions.

So I'll concentrate on some more precise estimates of speed at the tip as a starter.

The diameter of some these turbines is as much as 200 feet plus or minus a few feet..  So from our grade school mathematics we know that the circumference of the circle swept by the blades is 3.1459*200 (Pi times the Diameter) or about 628 feet.   Now to be going 160 miles an hour, how many turns of the blades will we have to have in a minute's time?

160 miles per hour is 160*5280 = 844800 feet in one hour.   So 628 being the distance of one turn will produce about 1345 turns in an hour or about 22 turns in a minute at 160 mph.  That's really moving and that's at the tip.  Of course at the center things are quiet just like the first kid in the 'crack the whip' fun on the lake.

So what gives?  Have we ever seen 22 turns in a minute as we drive by?  I've not seen anything going that fast and I've counted 1000 one, 1000 two etc out of curiosity.  I think it's possible, but I've not seen it so my friend's figures seem to be off a tad or he's out in a terrific wind.  Let's take something more reasonable.  Let's say 40 miles per hour at the tip.

We'd have ((40*5280)/628)/60 = 5.6 turns in a minute which I've seen.  I also think I've seen 15 turns with modest winds.  I think if the blades are moving faster than something reasonable, they disengage them from the gear system and the birds won't be flying anyway because the wind would be too high.  Pull off to the side and time them some time.  You can spare a few minutes.  Keep in mind also that there are 3 blades at work too.  To give my friend his due, the prevailing wind direction is from the west and the birds fly north, but he's talking world wide fatalities.

Now I don't have anything to say about the efficiency of wind systems as yet, but I refer you to the numerous Wind Turbine sites for further details on the bird issue.  It appears to me that a multi-pronged attack on the problem of power generation is better than numbers that we have to believe without thinking. How about some really good minds working on the coal fired emissions with a decent budget?

It's worth a little cost to see what happens, don't you think?.  Last time I checked nuclear power was costly and it takes years to produce a new and safe plant like we have near us.  OPG across Ontario is generating 12,062 Megawatts for Ontario presently with more demand coming.  They are using all sorts of sources.

How about the eye appeal of the Wind Turbines?  Well, lets see what they look like vs. what we've gotten used to looking at.  Notice the trouble the birds will have at night with these wires?  They don't go away with Wind Turbines either.  They run perpendicular to the fly-way

A good source of information can be obtained from the European Renewable Energy Council.

Wire Jungle crossing Highway 21 South of Port Elgin.  Majestic eh?

Mike Sterling