In some European countries wind power is contributing significantly to the energy mix. At EU level, wind is the second largest source of renewable energy after hydro. Since its early stages in the 1990s the development of wind-generated electricity can only be described as breathtaking. In 2010 the biggest producers were Spain (44,165 GWh) and Germany (37,793 GWh), followed by UK (10,183 GWh) and France (9,969 GWh). All data for this brief analysis covering the period from 1990 to 2010 have been taken from Eurostat.
To get a feeling for the tremendous growth of the sector we may note that at EU level wind power has soared by a whopping 537,000 % during the past two decades, delivering some 149,000 GWh in 2010. The result of this incredible surge is that in some countries like Germany, Spain, and Denmark wind can no longer be considered a negligible contributor to the energy grid.
Fig. 1 gives an overview of the annual changes of power produced from windmills during the period in question.
One stiking feature of this graphic is that the changes may also be negative, indicating that in the year n less energy has been produced than in n-1. This may happen as the amount of wind is fluctuating over the years. However, the negative growth rates are generally quite small, because new capacities are added every year. Moreover, with growing capacities in various areas the influence of prevailing calm tends to get weaker.
The other noteworthy issue is that the growths rates are slowly getting smaller. This is not surprising as the countries in our selection have already sizeable quantities of wind mills operating and the extra capacities added are small compared to the existing ones.
Fig. 2 gives an overview over the indexed production of wind-generated electricity with 1990 = 100.
The picture gives a vivid impression of the potential of this source of renewable energy. Although Spain and Germany are the top producers of wind energy, the top performers are Portugal and Italy. It may be noted that the countries selected are significantly outperforming the EU average. The reason is that in some Member States like Poland (1700 GWh), Bulgaria (680 GWh), Romania (310 GWh), and the Baltic states (550 GWh in total) wind power is still in its infancy stage, contributing very little, both in absolute and relative terms, to primary energy production. That may, however, be expected to change in the future. In Malta and Slovenia wind-generated electricity is virtually non-existing.
In spite of being an ever growing contributor to the energy grid wind power faces some intrinsic weaknesses which, paradoxically, tend to become more serious the bigger its contribution becomes. The main source of concern is the fluctuating availability of wind in the atmosphere. This, in turn, leads to fluctuations in the energy supply which put additional strain on the entire grid. Conventional power plants have to be kept in reserve in order to counterbalance the variable inflow from wind energy. This is one of the most pressing challenges to be tackled in the near future, if wind power is to be not only a significant but also a stable and reliable player in the whole energy mix.