Wednesday, 26 September 2007

Rudd critic tosses out some numbers on wind

Brandenburg Windfarm, Germany

Critics of nuclear energy sometimes point to Germany's planned nuclear phase-out policy as an example of the industry's limited future. Let us put aside the very credible discussions regarding the possibility of that policy being reversed for a moment and turn the tables.

How are German renewables performing?

As reported in the Herald Sun, Terry McCrann digs into the performance record of one of the largest wind powered systems in Europe.

Germany's E.ON Netz operates the grid which has one of the biggest 'feed-in' wind power sources in Europe. Each year it produces a WindReport. The latest makes interesting, sober, reading.

Germany has 18,300MW (megawatts) of installed wind capacity -- close to half Australia's total installed electricity generation capacity, about double Victoria's.

E.ON Netz draws on 7600MW of that.

In the precise German way, it tells us that maximum feed-in was 6234MW at 9am on 15/12/05.

Sound great? Except when you read the minimum feed in, at 12.15pm on 27/05/05. Just 8MW. And no, I'm not missing a nought or two.

Some 7600MW of installed capacity delivered just 8MW. When the wind don't blow, the electricity don't flow.

On average across the year, the 7600 MW of installed wind capacity produced 1327MW. That's an operational level of 18 per cent of capacity. In rational terms, it's insanity.

Indeed as E.ON Netz notes, installed wind capacity went up 12 per cent in the year but actual wind power fed in to the grid went up just 1.5 per cent. Because of lower "wind availability".

The way you 'solve' this is that 'traditional' power stations with capacities equal to 90 per cent of the installed wind power capacity must be permanently on line to guarantee power supply.

So not only do you have to install six to seven times as much wind capacity as the output you will actually get, but you also have to build 'shadow' coal/gas/nuclear(?) as well.

That's one power station for the cost of 12 or so.

Did I say insanity? Unless you can build big enough batteries to store the power generated when the wind does blow.

Funny I should say that. E.ON has actually pioneered exactly such a battery. It's the size of four shipping containers, uses 'undisclosed' chemicals and can produce all of 1MW for four hours.
See this link for projected vs. actual performance for any day (just select via the calendar on the right side of the page). Interested that they seem to always exceed the projection, but fall WELL short of the 7,600 MWe capacity. The 18% number looks about right from my perusal.

As much as I hate to be baited into nuclear vs. renewable discussions, the data bears careful digestion. Just as I've said from the beginning, when you objectify and quantify the discussion and base it on demonstrated performance - the picture becomes MUCH more clear. I've learned something though. In my previous back-of-the-envelope calculations, I was crediting wind with a 30% capacity factor. Seeing the 18% above, I guess I should pull that number back a bit.

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