Monday, February 23, 2009


Scott Bridges reckons Andrew Bolt is dishonest in noting wind speeds at Wonthaggi, Victoria, site of a wind farm:
Of course, Andy has selectively selected some days this week that show poor wind speeds, during a heatwave that features hot north winds and not the prevailing south-west winds for which the turbines were designed. He has also completely ignored wind data for the rest of January and previous months that show much more robust gusts of wind.
Bridges' linked data actually supports Bolt's argument, with January wind speed means of only 8 km/h at 9 AM and 15 km/h at 3 PM. According to a fact sheet provided by the wind farm, a wind speed of 12 km/h "is too low to justify operation of the machine". So, based on wind speed data from the Bureau of Meteorology, on average the Wonthaggi wind farm generated no power at 9 AM in January. Further, the "south-west winds for which the turbines were designed" blew on only parts of five days throughout the whole of the month. Bolt was essentially correct.

Bridges should more thoroughly research the stuff he posts; he is being paid to debunk dishonesty, after all, not write it.

Update: Rather than admit that Bolt was right, and Bridges wrong, Tobias Ziegler points to an error in my "statistical reasoning". Fair enough.

Bolt's point was that wind speeds at Wonthaggi were, for selected days, quite low. The BOM wind speed data show that for 23 of January's 31 days the 9 AM wind speed was below the wind turbines' stated threshold speed of 12 km/h. If the wind speed data and threshold speed are correct, anyone visiting the Wonthaggi wind farm at 9 AM on any of those 23 days would have seen the turbines standing idle. Further, on 15 occasions in January the 3 PM wind speed was below 12 km/h. Bolt's point is valid.

Update II: Bridges isn't about to admit he's wrong:
The argument seems to be that there is barely a wisp of breeze at this arbitrarily chosen moment each day so therefore the turbines are useless.
So Bridges' argument seems to be that the Bureau of Meteorology wind speed measurements are not representative of wind speed reality. This ignores that BOM does not take a wind speed measurement at "an arbitrarily chosen moment" but rather twice a day takes a ten minute reading each of which is averaged to produce the morning and afternoon wind speeds. Surely BOM scientists deserve some credit for knowing what they're doing.


Anonymous WB said...

I read that Scott piece as well. Talk about not landing a punch. His argument is that Bolt was selective in his quotes of windfarm power and Scott went ahed and did the same thing. But in his case, since he's apparently so anti-anti-wind farm, his argument is the more vulnerable of the two. Cos a crap power source that isn't reliable is just that - a crap power source. So Scott makes a lousy argument against Bolt and actually provides support to Bolt's argument about crap power from wind. I'd say incredible but he is a Victorian school teacher, and unless they're in TISM they're just not very bright.

11:33 AM  
Anonymous Dan Lewis said...

Will someone please tell me if I was supposed to be offended by the remark calling me a windmill...

1:28 PM  
Anonymous Anonymous said...

Anonymous...the term Barrister doesn't have to command the ultimate respect, like the term doctor did 30 years ago. Many (not all) of the Barristers I know are single (or divorced) 50 year old men, bonking their secretaries and pissing their not insignificant income up against a wall. Mehaul.

8:17 PM  
Anonymous Anonymous said...

Wind farms output is typically around 20% of what they are theoretically capable of. Not enough wind -> no power. Too much wind -> no power (they must be stopped to avoid damage). Bridges et al may whine about technicalities, but at th end of the day, wind farms are not a reliable source of electricity.

2:18 PM  

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