[Large Scale]



Principles of Operation, Current Status, Environmental Aspects and Planning, Economics

Large Scale Wind

Principles of Operation

The principles of operation of a wind farm can be found in the beginners guides (BG) under Wind. The general dimensions of the turbines used in large scale operations though are of interest:

Capacity: 600kW - 1.3MW

Tower Heights: 35m - 68m

Rotor Diameters: 44m - 62m

Rotor Speeds: 13/19rpm - 18/27rpm

Blade Lengths: 19m - 29m

Keeping these figures in mind some very interesting conclusions can be made, for example that it will take 5100 wind turbines to replace the Hunterston nuclear power plant and that they will need to cover 0.63% of the area of Scotland which is approximately 8.24 times the size of Glasgow.


Current Status

Before 1989 there were no Wind Farms in the UK, after the introduction of the Scottish Renewables Obligation (SRO or Non Fossil Fuel Obligation for England and Wales - NFFO) at the end of that year, developments began. The developments listed in table 1 are currently operating in Scotland. It can be said that the past three years have seen great increase in wind farm utilisation. With the introduction of the ROS (Renewables Obligation Scotland) even more developments can be expected. Currently most development is focussed around the advancement of onshore wind, which is a relatively well-developed technology; installation and integration now cause no great problems. Onshore wind yields lower costs, yet it has been proven that offshore wind farms can produce more energy and are thus could prove more efficient. In the future it is expected that power generation from offshore wind will increase, to what extent and how quickly this happens may depend on available funding and incentives. This is of special interest as, according to an October 2000 CADDET study, 20% of the UK's electricity needs can be covered by offshore installations. Types of wind turbine available on the market can be found at the following link: http://energy.sourceguides.com/businesses/byP/wRP/lwindturbine/byB/mfg/byN/byName.shtml


Table 1: Wind Farms operating in Scotland

Environmental Aspects and Planning

There have been many misconceptions around wind turbines, in general and wind farms in particular. The beginners guide to wind energy addresses these and explains the various reasons people are concerned about the environmental aspects of wind farms. When it comes to actually deploying wind turbines though, the story is a bit different. In theory many people read and understand various explanatory information packs about wind energy, but when it comes to projects starting in their area opinions change. The truth is that turbines are big and imposing structures and if one is close to one (50m or so) a humming noise can be heard due to the blades turning. On the other hand, big installations are not placed next to inhabited areas so as not to cause those sorts of problems. Most opposition comes from factors concerned with preserving natural habitats, national forests and beautiful landscapes. Some believe it is the way of the future and that it can even bring tourism and others believe that it can destroy landscapes forever. To list the considerations that need to be addressed when planning for a large wind installation:

It is obvious that many things have to be looked into apart from the economics and the payback period. In most cases projects that get approved have complied with the regulations concerning the above aspects in addition to being economically and technically viable.



It is very hard to put a price tag on a wind farm. The cost is site specific taking into account the types of turbines needed the cost of the land used (whether it be rented or bought). For the farm to be economically viable maintenance has to be taken into account, construction costs, transportation of parts, interest rates on the bank loan needed (in almost every case a bank has to lend the developers money) and so on and so forth.

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