The fluctuations in wind output are less than those of demand, and wind peaks often occur at the same time as demand peaks. Nevertheless, the steady export of power throughout this period, which averaged around 1000 MW to Sweden, Germany and Norway, is maintained even when there is little or no wind generation, such as during the March 3-5 period. When the wind generation increases substantially, such as on March 7 and March 13, exports rose at the same time and almost exactly matched the wind generation. It appears, in other words, that the system operators do not allow for wind in the scheduling and prefer to export most of the production rather than use less thermal generation. Exports continue even when increases in wind output are matched by increases in demand, as is often the case.
Demand, wind output and power exports: The spikes and troughs of electricity demand in Denmark follow an expected daily pattern, with most consumption in the middle of the day and the least in the middle of the night. Although the fluctuations are substantial, they are predictable, and the lower level of demand during the two weekends during the 14 days in March represented by this graph is clearly visible.