*Director of Environmental Services, Energy and Utilities
International, Logica
France is the only country in the world where a wind turbine has been burned by protesters and where the debate about exploiting the strength of the wind stirs up such lively exchanges. This is particularly harmful as France is the second largest European country in term of wind production potential (behind UK), with a capability estimated over 40 00 MW just for onshore production. Meanwhile, Germany and Spain have gone ahead with the installation of more than 2500 MW over the last six months without facing such major difficulties. As a result, the worldwide wind farms capacity will, in the coming months, exceed the 100 000 MW level.
The opponents’ arguments are myriad but to take only the two leading affirmations of French associated grouping: “Regulation of the demand, which is assured neither by hydro nor nuclear means, cannot be guaranteed by intermittent wind turbines. Moreover … for every MW of wind turbine capacity, one needs to build 3MW of thermal power for balancing purposes. The more wind turbines you put up, the more thermal power stations you need to build.”
So in other words the wind turbines would generate two significant issues. The first one being that they cannot participate in network balancing. The second being that wind farms are not necessarily producing at the time of peak consumption, which is usually during the winter in Europe.
The recent publication by RTE (Réseau de Transport d’Électricité – French Electricity Grid) of the document “Supply and demand of electricity balancing forecast in France” provides a serious rebuttal to this position. First of all, it should be noted that the load factor (relationship between the maximum power and the power produced) has for the last years followed a curve that is easy to predict (see diagram below).
If we obviously cannot impeach the wind blowing and thus are dependant of external factor for what’s about the wind farms output, we now can have rather accurate estimates four hours in advance, which is enough time to adapt other generation units including nuclear plants. On top of that, wind generation in France is still below 1 % and thus a variation of 30% of the load factor is still today insignificant in terms of overall national production and therefore easily manageable. This is hardly a cap to new installations when wind production already represents up to 20 % in other countries.More importantly, analysis of wind turbine production during the six winter months of in the years 2005-2006 shows that not only do wind turbines function effectively but they produce statistically 10% more in winter that during the rest of the year (load of 25.9% against 23.5%).
This first analysis, which encompasses a limited sample, is further confirmed by a study of Météofrance (French weather forecast agency) made over the last twenty years. The results of the study cannot be clearer: “the idea that the periods of greatest cold are associated with anticyclonic situations with very little wind is erroneous. The situations studied are all associated with periods of tramontana [FN1] or mistral [FN2] that are sometimes violent.”
Beyond the generally accepted ideas, these two studies therefore provide a total rebuttal to the argument that consists of correlating wind turbine production with the putting in place of thermal power stations to compensate for their stoppage during peaks in consumption. Not only do wind turbines produce effectively during the periods of greatest cold but their share in French national production today is in any case not sufficiently high to affect significantly the balance of the grid.
Once would argue that the situation is different in countries like Denmark where wind production already represents 20% of the national electricity consumption and a further 50% increase is expected before 2025. The same issue will arise rapidly in Spain, which beat its wind production record on the 19th of March 2007 with 8375 MW on line (72% of the maximum capacity). It is true that Denmark exploits at its maximum the ability to balance its position via import/export to neighbours. In particular, the Nordpool organisation is used heavily in order to export the electricity to Sweden during periods of high production whereas Swedish hydro capacity is used the other way around during low production period.
But in all countries with significant wind power production, initiatives are already taking care of the future. In Spain, Iberdrola is piloting a new system to store production temporarily using hydrogen and fuel cells. In Denmark, it is heating networks, which have been adopted as a key driver to improve the household’s energy efficiency, which are going to be used in order to store energy. And in both Germany and Spain, wind producers now are requested to take account of the balancing of the network and to offer system services and implement new control command systems for it.
More generally, the idea that production needs to fit with consumer demand will soon appear essentially obsolete. What the balancing of the network requires is a perfect fit between consumption and production. And the ability to adapt consumption is something which will appear quickly as an obligation and hopefully a reality due to the emergence in Europe of smart metering technologies. To return to France, the current technology allows EDF to switch off 6 000 MW during peak demand. The installation of 30 million smart meters and the development of demand side management propositions by the electricity retailers will allow this figure at least to double in the coming decade.
It seems that France is poorly placed in respect of its commitment to obtain 21% of its electricity production from renewable sources in 2020. France is clearly the bad student of Europe, with a green production that has collapsed from 18% to 12% over the last ten years. While the arguments associated with the visual impact on the countryside, grid reinforcement or the cost of production are admissible, the reports by the RTE and Météofrance clearly demonstrate that wind turbines in fact make a good contribution to a reduction in the emissions of greenhouse gases … a fact that should not displease their detractors.
Foototes
[FN1] Cold, dry wind blowing south or south-west from the mountains in Italy and the W Mediterranean.
[FN2] Cold, dry wind blowing north-south through the Rhône valley to the Mediterranean.