Big Wind Meets an Ill Wind - The answer to our electricity needs is not blowin’ in the wind.

“Not only aren’t the maintenance issues of the wind turbines considered, neither is the maintenance impact on the existing coal and gas fired units... those units used to go up and down slowly over the course of a day to reflect the increasing/decreasing demand of the grid. Now with wind entered into the mix, the coal and gas units are expected to go up and down like yoyos. Metal and thermal fatigue is a fact of life and like it or not, dragging wind into that mix will greatly shorten the life of these other power units.”

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Excellent, excellent point! I had never considered that aspect, but had only considered the raw loss of efficiency as the major cost of cycling those units, as they require a certain amount of time at any given output level to attain best efficiency at that level.

I attend the annual power conference almost every year and this is an issue that is just starting to get some attention.... there are a number of technical papers out now that address it fairly well. Given however that fatigue is one of those issues that never seem to get on the radar until problems occur, I suspect that it won't get dealt with until it seriously rears its ugly head and bites the appropriate authorities squarely in the a$$....which now that I think about it, shouldn't be too difficult given how deep they get their neck in the sand.

The basic problem with wind turbines is that it’s almost impossible to step back far enough to grasp the big picture… metal fatigue being a case in point since it is typically not something that happens immediately. You mentioned ‘the raw loss of efficiency as the major cost of cycling’….I’ve been studying overall efficiency as well but just ran into a new aspect of that this past year that I had never heard discussed before. The issue works like this…. Most jurisdictions with wind turbines also have other sources of electrical supply i.e. coal, gas, hydro, nuclear etc. and each have their characteristics (such as the one for gas that I mentioned in Post 15 which in that instance is so significant, it virtually negates all the electrical supply by wind turbines… but I digress). The problem with nuclear is that it does not lend itself to being increased or decreased in terms of output… it is only good for flat line base load supply. The problem is the spring and the fall for many jurisdictions….demand drops because air conditioning isn’t required and it is too early to need winter electrical heat. It is also the time that the wind typically blows hardest. Since almost all jurisdictions give wind power priority to the grid, this means that the electrical systems are way over supplied and because most nukes are quite large, it means having to pull units off line. This isn’t good and if you know something about nuclear power, the reasons are obvious….pull a nuke off line in response to a temporary spike in wind and you will be 3 days trying to put it back on line. Trying to run a grid with this kind of unpredictability as a fact of life makes for a highly inefficient system and in fact, once again a review of the big picture will tell you that operating under this condition with wind is significantly less efficient than having no wind at all. If the wind dies and the grid has nukes down, it means putting coal and gas back on line to make up the shortfall and if all of the headlong rush into wind was to try to reduce greenhouse gases, all of that ‘benefit’ is long gone. This gets back to a fundamental issue…. Should the control strategy for grids be driven by the available supply? Or by the instantaneous demand? I think the answer is obvious. Incidentally, here is a short section out of a program on Ontario’s publicly funded television network where this issue was discussed…. http://ww3.tvo.org/video/176598/green-energy-act-green Incidentally, the fellow describing the problem is with the Ontario Society of Professional Engineers (an organization that has a vested interests in all this as they are looking for engineering jobs amongst other things that they do)……first they lobbied for the engineering jobs that they thought the rush into wind would bring and now they are looking for the engineering jobs that involve solving all the problems that wind has wrought.

Oh and here is a very interesting link that has to do with overall grid stability with wind turbines feeding into it.... a pretty interesting response from the neighbouring countries to Germany, no?

http://www.thegwpf.org/poland-czech-republic-ban-germanys-green-energy/

Your example of bringing a nuke up and down is an extreme case of the raw loss of efficiency I intended to portray. That type of situation applies with any drastic change of output of a coal or any other generation unit. Some more, some less, however, there is always an extended period of time when efficiency is significantly lower any time a base unit has drastic change of output. For gas units, the time and efficiency loss is on the low end. Nukes are on the high end.

Thanks for bringing this all up, and thanks for the links. I will be checking them out later on.