This story is just attempting to highlight a very important and shocking interview on the bad economics and science behind wind farms in Ireland.
Val Martin from Kingscourt in Co. Cavan has just given a shocking radio interview on windfarms that is surely worthy of some debate on this site and elsewhere in the national media. (He was interviewed here: http://www.blogtalkradio.com/youngdan/2011/01/20/wind-e...artin .) David Bellamy, the well known environmentalist, says that 'wind power is a swindle' (1) and if you listen to the radio interview you might end up agreeing! And this is not an unimportant fact right now in Ireland because the government here have advanced plans to spend as much as 20 billion euro destroying the Irish countryside with these monstrosities, paid for via artificially increased ESB bills to pay the huge subsidies to the wind farm companies.
To give you some idea of the way that wind farms could end up costing us money, in maintanence and actually in using up electricity, rather than generating it, consider two simple issues:
Obviously all power sources will have to use some power to generate power but in conventional ESB stations these are well known, accounted for, and generally not all that significant. Say for example you take the very simple question of heating the building that the power station is in, which is obviously necessary in case equipment freezes etc. Well while obviously your average power station, in say Ardnacrusha, is quite large its after all only one building and surely doesn't cost gigantic sums of money to heat. On the otherhand the largest wind turbine currently manufactured is said to generate 16,300 MWh (2) a year while Ardnacrusha for example produces 332,000 MWh a year which means that even if you install the biggest turbines possible you still need about 20 of them to correspond to one power station, at best. But you have to heat each one of the turbines as well - they have heating coils going through them, they cannot afford to have them freeze etc - and these are enornous things exposed on the side of mountains. You can imagine that that simple thing, while small for a normal power station is a major headache for the wind farms. During the recent bad weather in the UK it was found that the wind farms were using up more electricity than they were generating, because of this simple issue (3).
b) Maintenance of the Machinery.
Again there is always going to be a cost associated with keeping equipment running reliably but there are particular problems again for the turbines. In Ardnacrusha for example you have 4 turbines, being fed by water flowing through pipes of 6 metres in diameter, to maintain. It wouldn't strike you as an enormous headache to do that and don't forget they are set into artificially created concrete channels which are not likely to create unexpected conditions. Remember now that for the wind farm you have to multiply that maintenance by 20, because a very conservative minimum of 20 turbines corresponds to one power station, and the diameter of the blades on some of these 6mw turbines are 126 metres! (4) To keep very advanced esoteric equipment like that maintained obviously requires either huge over the top and very expensive engineering specs when they are built (they talk about, for example, 500 tons of concrete for the foundation for each turbine) or they use very unusual and, of all things, electricity intensive ongoing maintenance procedures. So for example the wind farm operators routinely turn the turbines, via electricity from the grid, when they would otherwise be static because they need to for maintenance reasons. Otherwise they would run into enormous problems with buckling and warping of the blades (due to their weight or the sun etc) if they remain static for too long.
Here is a quote on this serious long term maintanence issue:
"'In large rotating power trains such as this, if allowed to stand motionless for any period of time, the unit will experience "bowing" of shafts and rotors under the tremendous weight. Therefore, frequent rotating of the unit is necessary to prevent this. As an example, even in port Navy ships keep their propeller shafts and turbine power trains slowly rotating. It is referred to as "jacking the shaft" to prevent any tendency to bow. Any bowing would throw the whole train out of balance with potentially very serious damage when bringing the power train back on line.
'In addition to just protecting the gear box and generator shafts and bearings, the blades on a large wind turbine would offer a special challenge with respect to preventing warping and bowing when not in use. For example, on a sunny, windless day, idle wind turbine blades would experience uneven heating from the sun, something that would certainly cause bowing and warping. The only way to prevent this would be to keep the blades moving to even out the sun exposure to all parts of the blade.' So, the point that major amounts of incoming electrical power is used to turn the power train and blades when the wind is not blowing is very accurate, and it is not something the operators of large wind turbines can avoid.
'[Also, there is] the likely need for a hefty, forced-feed lubricating system for the shaft and turbine blade assembly bearings. This would be a major hotel load. I can't imagine passive lubrication (as for the wheel bearings on your car) for an application like this. Maybe so, but I would be very surprised. Assuming they have to have a forced-feed lubrication system, given the weight on those bearings (40 tons on the bearing for the rotor and blades alone) a very robust (energy-sucking) lubricating oil system would be required. It would also have to include cooling for the oil and an energy-sucking lube oil purification system too.'
--Lawrence E. Miller, Gerrardstown, WV, an engineer with over 40 years of professional experience with large power train machinery associated with Navy ships." (5)
- yaw mechanism (to keep the blade assembly perpendicular to the wind; also to untwist the electrical cables in the tower when necessary) -- the nacelle (turbine housing) and blades together weigh 92 tons on a GE 1.5-MW turbine;
- blade-pitch control (to keep the rotors spinning at a regular rate);
- lights, controllers, communication, sensors, metering, data collection, etc.;
- heating the blades -- this may require 10%-20% of the turbine's nominal (rated) power;
- heating and dehumidifying the nacelle -- according to Danish manufacturer Vestas, "power consumption for heating and dehumidification of the nacelle must be expected during periods with increased humidity, low temperatures and low wind speeds";
- oil heater, pump, cooler, and filtering system in gearbox;
- hydraulic brake (to lock the blades in very high wind);
- thyristors (to graduate the connection and disconnection between generator and grid) -- 1%-2% of the energy passing through is lost;
- magnetizing the stator -- the induction generators used in most large grid-connected turbines require a "large" amount of continuous electricity from the grid to actively power the magnetic coils around the asynchronous "cage rotor" that encloses the generator shaft; at the rated wind speeds, it helps keep the rotor speed constant, and as the wind starts blowing it helps start the rotor turning (see next item); in the rated wind speeds, the stator may use power equal to 10% of the turbine's rated capacity, in slower winds possibly much more;
- using the generator as a motor (to help the blades start to turn when the wind speed is low or, as many suspect, to maintain the illusion that the facility is producing electricity when it is not, particularly during important site tours) -- it seems possible that the grid-magnetized stator must work to help keep the 40-ton blade assembly spinning, along with the gears that increase the blade rpm some 50 times for the generator, not just at cut-in (or for show in even less wind) but at least some of the way up towards the full rated wind speed; it may also be spinning the blades and rotor shaft to prevent warping when there is no wind. (6)