Survey of Energy Resources 2007
The way in which wind energy has developed has been influenced by the nature of the support mechanisms. Early developments in California and subsequently in the UK, for example, were mainly in the form of wind farms, with tens of machines, but up to 100 or more in some instances. In Germany and Denmark the arrangements favoured investments by individuals or small cooperatives and so there are many more single machines and clusters of two or three. Economies of scale can be realised by building wind farms, particularly in the civil engineering and grid connection costs and possibly by securing 'quantity discounts' from the turbine manufacturers. Economies of scale deliver more significant savings in the case of offshore wind farms and many of the developments involve large numbers of machines. Fig. 12-5 gives an indication of typical parameters for offshore and onshore wind farms. The offshore project uses machines with the same rating as the onshore project but machine outputs for offshore installations are expected to increase in the future - to 5 MW, and possibly more.