Show us the money!

Models are only as valid as the data and assumptions used in their construction. If the author's view really withstands scrutiny, then the models should be beyond criticism. So let's see them.

Sylvia.

I would be pleased to learn Professor Diesendorf’s view on accidents and fatalities in the wind industry.

A partial list of accidents and fatalities can be found at the following site and click on “accidents statistics.”

http://www.caithnesswindfarms.co.uk/

The summary has been updated to Nov 30th 2007. It is admitted that data is incomplete; however, it does represent the “tip of the iceberg.”

Could Professor Diesendorf provide southern hemisphere data? Discuss most frequently observed accidents in Australia. To bring the wind data in line with the Switkowski report could we know please the fatality rate for wind generation expressed as GWe/year.

Mark Diesendorf's criticism of Tom Quirk's use of a "reliability figure" is unwarranted. This is essentially the same methodology that NEMMCO applies in its annual statement of opportunities (SOO). Indeed in its 2007 SOO, NEMMCO assumes only 8% of the capacity of SA wind farms.

NEMMCO is an independent body, run by power system boffins, with no axe to grind in respect of technological outcomes. They are influential in setting market parameters (e.g. intervention from time to time and the price of VoLL (the market cap price)) and, as such, one would generally expect that, with their influence, the market will be driven to provide the capacity they believe is required.

The 92% haircut to wind farms is therefore a real cost because that capacity must be found elsewhere. If a kW of wind costs $2,700 (recent Australian prices) then it also requires a further 0.92kW of back-up from, most cheaply, a gas turbine at say $600/kW for a total cost of $3252/kW.

My point here is that it is all very well for wind backers to talk about geographical diversification and new forecasting tools but if the independent, and expert, market operator is only prepared to assign a firm capacity to wind farms of 8% then that haircut is real and represents a real cost to our society. Under these circumstances the debate about achievable penetration levels is, largely, a wasted one. Any additional MW of wind gets the 92% haircut and its backers should contemplate that off-takers should sensibly be heavily reducing the price they are prepared to pay for its electricity (excluding the renewable credit).

The wind debate is rife with mis-information and confusion, but intermittency is truly a big issue the wind industry and our politicians need to face squarely.

1/. Wind Energy pure lacks an energy storage system, which is available to all power stations, coal, oil, or nuclear. gas less so. In the "coal pile" beside/inside the station.

2/. Present wind energy technologies are "out of date" their mechanical principles go back at least to 1185 in UK, and possible to 635 AD and before in Iraq ! A fan, a gearbox, and something driven.

Modern wind energy technology pioneered by Honneff in 1932, The Third Reich 1935-45 and Trimble's Windmills 1972-82 used two rotor contra rotation to eliminate gearboxes, and improve overall aerodynamic efficiency. Some Timblemills are still operational
Work is now starting in UK to develop larger machines with better electrical technology.
See the files on axialflux@yahoogroups.com for articles/references.

3/. The best application for wind energy is heating/cooling, as when the wind blows energy loss/gain to a building increases. This can be "balanced" by a wind turbine supplying energy to the building.

No mention here has been made about response time.
Whether geographical spread helps or not there is one factor that
has not been discussed.

When wind farm output falls, to the cube root of wind speed mind you,
can the the thermal power stations be cranked up at the same rate ?

The change in level can be very large, a drop to one third in wind speed
means a drop to 1/27th in output.

Then as the base load station starts picking up the load, the wind picks up.

These are just the factors that start an oscillation which can cause
loss of system control.
I believe this is what happened in Germany.

One suggested answer is gas fired turbines, but even those have to
be kept running, just in case.