Introduction

Wind Power in France… [sigh]

Despite being the largest country in Western Europe, Wind Energy has not been developing in France as much as one could have imagined. There are several reasons to this, for now let us just hope for some quicker developments in the years to come.  I have gathered a number of interesting documents showing that a number of detailed study were carried out and some prototypes built, before the decision was taken to stop the French Wind Energy program. Let us go through some of them.

You may remember that I already mentioned the French Wind Energy program in an earlier post. In 1974 in Stockholm, René Bonnefille from EDF presents the following paper:

• French Contribution to Wind Power Development – by René Bonnefille from EDF (Stockholm, 1974). (Link to ToC of the conference)

The article is only one page long, I am not providing it here because it is basically a summary of a report in French, see full reference and link below. The message from Bonnefille is clear: as of 1974, France will not continue its Wind Energy program.

• Les réalisations d’Electricité de France concernant l’énergie éolienne, by René Bonnefille (1975). (Link)

This well written and well documented report provides a rather detailed overview of the numerious wind turbine prototypes built in France in the 1950s and 1960s. I won’t re-do the description of the famous BEST-Romani turbine of Nogent-le-Roi (800 kW), or the less known Grand-Vent 100 kW 2-bladed pneumatic turbine, see them in pictures below. You can find out almost all the details about the Nogent turbine on this website, maintained by the son of the former director of the test site.

The report from Bonnefille provides a number of positive arguments about Wind Energy, and highlights the successes of the prototype testing. Therefore, and as written in this nice summary from Les Cahiers d’Eole no. 2, the cost of the electricity produced, about 30% higher than other sources, combined with the growing interest for Nuclear Energy, led to the decision of stopping the project. Actually, as detailed in this PhD thesis by Ms. Gueorguieva-Faye and also reported elsewhere, the role of Pierre Ailleret, director of studies at EDF was key for both wind and nuclear energy. As Diana Gueorguieva-Faye explains, after having well developed both wind ressource and turbine prototype studies, Mr. Ailleret left Wind Energy and focused on Nuclear Energy. Without him some momentum was lost and the program was abandonned. I am providing below the full reference to Ms. Gueorguieva-Faye’s thesis:

• Enjeux autour de l’énergie électrique éolienne en Ardèche.La construction sociale du plateau de Saint-Agrève, by Diana Gueorguieva-Faye (2007). (link)

The Wind Resource of France

Pierre Ailleret took part in the creation of Electricité de France (EDF), after the war. At that time the main focus was hydro-power, and he made efforts towards assessing and exploiting other renewable energy sources, that is: wind and tidal, see (Gueorguieva-Faye, 2007) page 23. He initiated the first large scale wind measurement campaign dedicated to wind ressource assessment in 1947-48, and the first results were published by Louis Serra (also from EDF) in 1953, see three related publications below:

• “L’énergie éolienne: sa valeur et la prospection des sites”, by P. Ailleret (1946), library link.
• “La recherche des sites qui pourraient convenir à une utilisation du vent”, by P. Ailleret (1948), library link.
• “Le vent en France et ses possibilités d’utilisation”, by L. Serra (1953), (library link).

One could say that by taking his approach France had the same thoughts as Sweden in the early 1970’s. First, it remained to be solved how much wind energy was available in France, and if it turned out to be large enough compared to our needs, then turbines should be designed for exploiting it. As to the americans, they did both at the same time, see here.

Now let us continue with Ailleret’s 1946 and 1948 studies. If you follow my posts weeks after weeks (I doubt it, but..) you will be glad to hear that he refers to the Eiffel tower measurements shortly described in this post. His aim is to gather a set of consistent measurements across the country, also from isolated locations. Therefore he proposes not to rely only on typical manned weather stations. Instead, he suggests to use at each site the same type of instrument: a cup anemometer linked to a wattmeter, which measures the available wind energy (times the Betz limit) between two readings. The anemometer was calibrated in a wind tunnel, see a picture of the instrument and an example of readings:

The guiding principles for placing the measurement stations are the following:

1. Measurements should be carried out at already existing long-term measurement stations (Eiffel tower for instance).
2. At several stations, measurements will be carried out at different heights above the ground.
3. Coastal areas are great places to measure wind, so 21 measurement stations will be located on lighthouses.
4. Stations that do no measure enough wind, or that measure wind conditions very similar to neighbouring stations will be relocated to t other places.
5. Finally, at a small number of stations measurements will be carried out using some Richard Frères anemo-cinemographes to get an indication of turbulence.

In 1953, Louis Serra uses this measurement dataset, and writes a wonderful paper were he ends up deriving the first European Wind Atlas ! Let us go through some of the main steps of his analysis. As I wrote a little earlier, Ailleret started to research Wind Energy because it was possibly a nice complement to hydro (nuclear wasn’t a thing yet). So Serra starts by focusing on the monthly variations of the wind speed observed at the Eiffel tower between 1890 and 1909 (and again, he refers to the work of Angot). This 20 years period is reffered to as “the normal period”. He compares then the mean wind speed annual profile during the normal period to the one observed during the 1946-1953 period and finds them quite similar. See below how the data look like. He also compares the mean wind speed over the two periods: 8.8 m/s in the normal period, compared with 7.8 m/s between 1946 and 1953.

He goes on by plotting the mean wind energy profiles at the locations where measurements are available at several heights, and by grouping those that have single height measurements, but are in similar locations. Judging from the plot below, coastal of lighthouse stations have similar profiles (the shear exponent is approx. 0.2).

Follows a wonderful discussion about the two main wind climate of France (oceanic and mediterranean), where it appears that those are likely little correlated. By roughly scaling the measurements with height using the previous Figure, he derives a nice wind energy map of France:

Louis Serra does not stop here. He continues by providing some results of wind profile experiments using smoke rockets (“fusées fumigènes”) ! See the report if you are curious (the results are not that conclusive). But his major contribution is the first European wind map, derived by combining a number of national studies, see below:

• “The potentialities of wind power for electricity generation (with special reference to small-scale operation)” by Golding and Stoddart (1949) link.
• “A report by Proff. Rezzani” for Italy (if you know what is this reference, let me know please !!, it may actually be from Vezzani, reffered many times in this wonderful 1954 WMO report).
• “A study by R. Wartena” for Belgium and the Netherlands (it may be the brochure mentioned here).
• Climate databases for Spain, Denmark and USSR.

Serra concludes by considering how many turbines could be installed across the country, and derives regional net energy production. He also mentions that the monthly wind energy production complements nicely the hydro production, see below.

Thoughts

It could be the that the French wind energy program came too early, and got overtaken by the nuclear program which was fitting better in the 1960’s context. After all Denmark gave up too, in 1962. The French prototypes were not the only ones plagued by fatigue and blade issues, and it feels a bit sad to see that as the momentum in the French projects was at its lowest point when the industry picked up in the US. The program launched by Ailleret achieved some great results though, and its claims for a strong French wind power sector are still very much actual. It just seems that some key people either retired, or switched to other fields (nuclear), and that was enough for bringing down the program.

One could question whether modern wind energy would have been a thing without the – yet unsuccessful – but huge investment from the US federal government in its 1970’s program. Before that, the pionneers (Juul, Golding, Hütter, … and I will now add Romani) had only prototypes without strong backup from the industry or the state. Hard to tell why the momentum fell so low about wind in France, why France did not follow along the US program, together with the other european countries. It really has not been the lack of support from grassroot environmentalist movements, maybe was it just the huge effort of developing civil nuclear that absorbed all attention, I don’t know, but, let us just change that in the years to come :).

Anecdotically, how interesting to consider that Juul measured the site conditions at Gedser using one the anemometers designed for the Ailleret campaign 🙂 !

Comments/questions are welcome,

Rémi