Survey of Energy Resources 2007
Wind Energy - Integration into Supply Networks
Electricity systems in the developed world have evolved so as to deliver power to the consumers with high efficiency. One fundamental benefit of an integrated electricity system is that generators and consumers both benefit from the aggregation of supply and demand. On the generation side, this means that the need for reserves is kept down. In an integrated system the aggregated maximum demand is much less than the sum of the individual maximum demands of the consumers, simply because the peak demands occur at different times.
Wind energy benefits from aggregation; it means that system operators cannot detect the loss of generation from a wind farm of, say, 20 MW, as there are innumerable other changes in system demand which occur all the time. Numerous utility studies have indicated that wind can readily be absorbed in an integrated network at very modest cost (IEA, 2005) until the wind contribution on an energy basis reaches about 20% of electricity consumption. Beyond this, some wind power may need to be curtailed on a few occasions if high winds coincide with low demand, but there are no 'cut-off' points. Practical experience at these levels is now providing a better understanding of the issues involved.