You raise a number of very interesting points, Pete. I obviously cannot 
answer them all especially as I'm not in the US of A. I'll therefore 
speak more in generalities than give you specific answers.

The overall balance sheet of windfarms is very difficult to establish 
because it depends on the amount of wind, obviously. No typical turbine 
produces any output with wind speeds under 4 m/s and very few reach full 
output at 10 to 12 m/s and they stop producing at 20 to 25 m/s. This 
implies that the best sites require average wind speeds of 8 to 12 m/s, 
without excessive amounts of gusts exceeding 20 m/s. In Europe, the best 
places are hilltops or offshore in the North of Scotland or parts of 
Denmark. The cost of the electricity produced in these places is not 
much more than from conventional power stations and it is possible to 
make them economically viable. At the other extreme, on this island of 
Cyprus, we have four windfarms and none of them are economically viable 
because the highest average wind speeds are just over 4 m/s. The cost of 
the amortisation, maintenance and running costs including manpower 
exceeds the selling price of electricity (already very high) by a factor 
of two. So the answer to your first question is really how long is a 
piece of string?

The cost in energy is reasonably favourable with the well sited 
windfarms. A typical turbine, with an estimated lifetime of 25 years, 
including the spares over that time, will produce about 20 times as much 
energy as it takes to make, transport it and install it, over its lifetime.

Provided that the conventional electricity is sufficiently flexible to 
be adjusted to variations in the electricity production from wind farms 
or solar farms, I personally consider them to be a useful addition to 
our armoury of electricity production methods, if everything is 
correctly managed. On the other hand, a badly managed system where the 
grid is not flexible in that supply and demand makes the viability of 
windfarms much less obvious.

I am not too familiar with corn cultivation and I understand that you 
export much more than you consume. However, I do recollect, a few years 
ago, that increased biofuel production from corn caused a shortage and 
exports to e.g. Mexico suffered to the extent that they were 
insufficient to meet the demands of the Mexican population for their 
staple food. In my opinion, this is very wrong; food demands and 
supplies should have first priority and only anything left over or of 
poor quality should be used for making biofuels. However, with the 
question of wind, you ask for the environmental viability. It is well 
known that ethanol production from corn is heavily subsidised, 
suggesting that the product is far too expensive to add to gasoline. 
Nevertheless, the amount of carbon emissions of machinery used in 
ploughing the fields, sowing the seeds, harrowing, irrigating, 
harvesting the corn and transporting it to the distillery, is far 
greater than the carbon emissions would be from the gasoline that is 
saved! And this does not take into account the carbon emissions used in 
manufacturing the chemical fertilisers which are also spread on the 
fields. For me, this is called shooting oneself in the foot!

In my opinion, the production of ethanol from corn is a total anomaly as 
a means of providing fuel. The fact that it is costing the country a few 
zillion dollars in subsidies is also an anomaly and the money could be 
better spent in providing better conditions of life amongst the 
poverty-stricken, although this is a political point which I am not 
qualified to promote.

I hope this information will clear your mind of a few of the questions 
you ask.

Brian

On 25/08/2014 17:03, Pete wrote:
> Sorry to dredge this up after it's been quiet for a few weeks, but...
>
> I've been on vacation.  Spent 2 weeks driving around the US of A.  This conversation struck me, because among all of the amazing things things I saw, 2 were rather significant because they seemed un-natural.
>
> Wind farms.  LOTS of wind farms.  Corn.  INSANE amounts of corn.  Both left me with the same thoughts of a wasteful use of resources.
>
> Wind farms.  What did it cost to build them?  Operate them?   Not just in dollars, but in energy, too.  At least half of them, probably more, weren't even spinning regardless of the wind action.  If we had spent those dollars cleaning up toxic chemicals or even Ebola vaccines, we could be saving many lives each day instead of jousting the windmill of maybe reducing global temperatures by a degree in the next 100 years.  Or maybe spend those dollars on research into viable clean energy to replace fossil fuels.
>
> Corn.  No way the country is eating that much corn.  Sure the energy balance for corn-ethanol is getting better (thanks to GMOs - uh-oh!).   But again, is this the BEST use of those resources?   Could we be growing better food in those fields, making fuel from something that has a better energy balance, spending the money more efficiently?
>
> And another point was made that has always made me wonder.  We generate a LOT of heat to make energy.  Has anyone ever studied if that has more effect on climate change than the emissions?
>
> Pete
>

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