The new electricity law has, among other things, put wind power back at the heart of debates about the energy transition.
We reproduce here the excellent synthesis on wind energy produced by the popularization and awareness platform WattED, a synthesis designed in the form of answers to six arguments commonly used by opponents of this energy source.
The Federal Office of Energy (OFEN) recently re-evaluated the Swiss potential, ten years after its last analysis. Since then, wind turbines have made technical progress and Swiss legislation has become more permissive regarding siting (forest zones in particular). All combined, this raises the theoretical potential from 3 (previously announced) to 30 TWh/year!
30 TWh/year is huge; it's much more than the country's remaining three nuclear plants!
However, this remains a theoretical potential linked to the deployment of more than 4'000 (large, > 4 MW) wind turbines, whereas Switzerland has so far installed a little less than fifty (historically smaller, around 1 to 3 MW), and about thirty were recently unblocked by the Federal Court. Different scenarios generally assume exploiting at most about one third of this potential... the exercise remains interesting nevertheless.
But do we even have the space to install these wind turbines? This is obviously a parameter that OFEN took into account. The analysis considered the following constraints:
- The physical potential relative to the 2019 wind atlas.
- A 300-meter buffer zone around dwellings for noise protection.
- The exclusion of protected zones.
Zones to be examined within planning
Verdict: Switzerland has a considerable potential for electricity production from wind!
There is a confusion here about the meaning of the capacity factor. If it is indeed between 20 and 25% for onshore wind, it does not provide information on the number of operating hours. It indicates the ratio between actual production and the theoretical production if the installation ran at full capacity continuously. In practice, moments with no wind production in Switzerland are very rare. But it is worth keeping this figure in mind when one wants to compare very different production means on the basis of their installed capacity.
Argument 2bis - "On the contrary, I read that they run 98% of the time"
This refers to the availability rate. This, inherited from thermal power plants, tells us the actual operating time compared to the time when conditions are favorable for operation. It is a ratio that allows us to know how much maintenance an installation requires (and wind turbines perform very well on this indicator). By construction, this data does not take into account periods when the wind is too weak or too strong for the installations to operate.
Are these inactive periods important? It depends on the installations. But is the question even relevant? It may be more useful to think at the scale of a whole park than at that of a single turbine.
What interests us above all is the timing. Currently, we face two issues:
Reducing greenhouse gas emissions, and for that we need more decarbonized electricity
In Switzerland, there is now a large shortage of production in winter
In this game, wind power is relevant. 67% of its production occurs in the autumn-winter period, where the need is greatest and where the carbon content of electricity is highest (see the visual below). An ETHZ study also seems to show that Swiss wind regimes are complementary to European regimes.
So, does intermittency pose no problem? If the word intermittency is correct, it may be more understandable to speak of variability. As we have seen, even with a small number of machines like in Switzerland, moments with zero production are almost non-existent (one hour in 2022). However, the variability of injected power is strong, which represents an additional challenge for grid management, already the poor relative of the transition - let us recall that it took 20 years to erect the Chamoson - Chippis high-voltage line (VS). Grid financing (always more essential, despite decentralization) is a key issue on which debates are far from over!
This assertion is often heard, with the German model referenced which aims for a very strong deployment of intermittent renewables (solar, wind). When conditions are unfavorable, they are for now supplemented by fossil plants (whose greening is promised/ hoped for).
Yet, this statement cannot certainly be judged correct in a context like Switzerland. Since wind turbines supply 2/3 of their production between October and March, their production is generally more than welcome in a Switzerland that has become a winter importer for several years. Even if we had too much energy at that time, that would certainly not be the case of our neighbors who would be buyers of decarbonized energy (which has priority).
Interconnections facilitate the integration of intermittent sources. Nevertheless, these will require substantial investments in cross-border transmission lines, alongside the necessary modernization of the domestic grid.
In Switzerland, wind turbines have another powerful ally in our dams, which can quite well offer the service of absorbing a possible surplus to release it later when the wind is weak and demand is strong. Conversely, if they are well filled, they can also cover two anticyclonic weeks during which the wind would not blow.
That is why all low-carbon scenarios from Swiss scientific bodies rely on a substantial deployment of wind power, despite its relative lack of popularity compared to solar.
Other solutions also help improve the integration of intermittent production as long as the temporal shift is not too large: for example electric vehicle batteries or shifting demand (laundry, dishwasher, water heater...). This is already very intuitive for solar panel owners aiming to optimize their self-consumption, but it could also be relevant in the event of massive wind deployment with dynamic electricity tariffs. In addition, very large industrial consumers can accept adjusting their production in exchange for financial compensation (this is called temporary demand reduction).
In all cases, these issues must be thought of taking into account the entirety of the available grid infrastructure.
A criticism often made of wind turbines is their impact on local fauna, especially birds and bats. Last year, it was notably a golden eagle that lost its life, struck by a blade at Mont-Crosin (BE), followed by powerful images that, circulating in the media, helped shape public opinion. Beyond the understandable emotion following the death of such a rare and noble animal, it is appropriate to look at the figures in detail to take a step back.
The figures obviously vary greatly depending on a whole series of parameters (country of installation, blade size, proximity to avian zones...), but for Switzerland, the only study on the subject seems to indicate around twenty bird deaths per year per turbine, or about one thousand at present - and possibly several tens of thousands in the case of a massive deployment of wind power in Switzerland. Of course, these accidents often also concern "common" birds (much more widespread than the golden eagle of Mont Crosin) - kinglets, thrushes, mallards...
Once this absolute observation is established, it is necessary to look at these figures in relative terms to answer the following question: Is that a lot?
To answer, let's compare with other dangers looming over avian fauna. And among these threats, one that we particularly cherish in our regions: the cat!
Again, figures vary greatly depending on parameters (country, cat habits, ecosystems...) but overall, we obtain a range of 20 to 250 birds per year per cat. In Switzerland where the number of cats is around 1.7 million, OFEN articulates the figure of 30 million birds killed per year. Certainly, we've never seen a cat attack a white-tailed eagle but quantitatively - it's a completely different scale - 1000x more!
By the way, if your cat has outdoor access, consider keeping it inside on spring mornings and equipping it with a colorful collar (www.pikpik.ch).
As for the trio coal - oil - gas that wind power must help replace, their impact on wildlife is just as massive. According to Audubon (USA), two-thirds of North American bird species are threatened with extinction by climate change. A completely different scale!
Given these figures, it is difficult to find this argument rational for slowing wind power, even though every bird killed is one too many. And how to compare the "value" of a peregrine falcon to thousands of tits, bats, lizards or shrews?
Fortunately, researchers are multiplying initiatives to try to limit the impacts of wind power (painting blades, installing radars...). Sometimes this will be at the expense of wind production, which will lead to further environmental and financial trade-offs!
It's true that a modern wind turbine is quite a machine; given the significant efficiency gains, they have continued to grow, each requiring thousands of tons of concrete and steel. But there is no point in looking at the absolute balance without relating it to the kWh produced! The good news is that this has been studied for a long time, taking everything into account from raw material extraction to the decommissioning of installations.
Result? According to the IPCC, it is the lowest-carbon energy in the world; a kWh of wind will have emitted 40 to 100 times less CO2 than if it had been produced with gas or coal.
But an impact is not measured only at the CO2 level; we must take into account other parameters such as biodiversity (cf post 4/7) or the availability of raw materials. Here, we must admit that it is a bit more problematic: we know that solar and wind require immobilizing more minerals than historical production modes. The IEA keeps reminding us that the raw materials are there, but that we risk missing the transition if we do not extract them quickly enough (in addition to promoting recycling of the quantities already present in our society).
One element on which there is an urgent need to improve availability is copper, crucial for solar, wind and the indispensable development of the grid. Another important element for wind turbines: certain rare earths (Neodymium, Praseodymium, Dysprosium, Terbium). They are not really rare, but their extraction and refining are complex and polluting, and very few countries do it. This leads to a major risk of dependence on China, by far the world leader in the field, which could cut the tap at any moment.
Can we make wind turbines without rare earths? Yes, but performance suffers, more of other materials are needed, and maintenance is more frequent (increasing travel and costs)... Again, a matter of trade-offs!
As for end of life, there is no problem for what represents the vast majority of the weight: steel, copper and concrete, we are used to that. The painful part is the blades made of composite materials, currently non-recyclable. You may have already seen photos of wind turbine blade graveyards buried by the hundreds? This happened in the past in the USA, but never in Europe, where it was always forbidden.
There are still few turbines at the end of life, but the question of blade management will arise in some pioneer countries at large scale, hence valorization projects. And science is working on new alloys aimed at 100% recyclable turbines within 10 years (which does not mean, however, that we will remake a new turbine with an old one).
A wind turbine is big and can be seen from afar, that's for sure. Their increasing size, the result of technological advances, has a specific aim: to maximize energy production per resources invested. Power being dependent on wind speed and the surface swept by the rotor, you have to go high and aim wide. This race for gigantism is not industrial vanity: it optimizes many indicators - such as the material consumption we discussed last week. To reduce it, one must tend toward the most efficient installations possible. More discreet wind turbines are therefore possible, but more resources will be needed to obtain the same production. You begin to know the principle: AR-BI-TRA-GE.
In Switzerland, the models used by OFEN for its studies are machines ranging from 92 m in diameter for a height of 100 m, to 160 m in diameter for 150 m tall. The maximum potential we find, on the Energyscope site, is 30 GW. In that case, this would represent a wind park covering an area roughly equivalent to that of French-speaking Switzerland, excluding mountainous zones. But no scenario speaks of such production. A recent study shows a technical capacity of 18 GW (see the first post in the series). This would then be an area larger than the canton of Vaud. The current strategy aims for a few hundred wind turbines, equivalent to a region the size of the canton of Obwalden (or half of the Jura).
These areas are impressive, but the notion must be clarified. If we set aside the visual impact and focus on land artificialization, namely mainly the access road and the concrete base, this represents 1% of the area. A very large part of the area between the masts remains intact. It can be used for agricultural needs or left to biodiversity capable of coexisting with these giants.
Those are the numbers, but let's come to the heart of the matter: degraded landscapes. And here, it is a matter of tastes and colors. The rotation of the blades induces a stroboscopic effect that can be unpleasant for residents exposed to it. With noise, it is one of the reasons why the minimum distance must be 300 meters from dwellings. At present, no study can show other health impacts (nor on dairy cows that graze below). It is therefore above all an aesthetic question. Judgments will also vary depending on the quantity deployed and their height. Inevitably, turbines with capacity >4MW will impact the landscape more than old models <3MW.
Wind power is visible and reminds us of the weight of our energy consumption.
Wind power faces a lot of opposition, often for false reasons, but also for acceptable reasons - notably landscape impact. But compared to the ravages that major climate change will cause, compromises will have to be made regarding some "undesired" solutions in order to move forward.
To see what the specific future planned for wind power is in a transition aiming to exit fossil fuels, we reviewed all scientific 2050 scenarios for Switzerland.
Compared to the technical potential, around 21 GW (> 4000 turbines, covering an area equivalent to the canton of Bern), scenarios generally place themselves in an "acceptable" range from 0.7 to 4 GW (although one study goes against the tide by pointing to the economic and functional optimum in exploiting the maximum potential). And moreover, the "WindExpress" law voted in Bern pushes for an acceleration of procedures for new sites until at least 0.6 GW are installed.
Even if we would remain very far from exploiting the total technical potential, this still means between 200 and 1000 wind turbines, which would remain a very strong acceleration compared to the 41 painfully installed so far. It is also necessary to put the Swiss trajectory into its European context. Projecting to 2030, the Swiss are an exception in terms of wind power. If our technical potential is demonstrated, it must nevertheless be nuanced by another explanation: our population density. It is difficult to install a turbine without bothering anyone.
International decarbonization scenarios also rely on a significant deployment. In our French neighbors, they talk about 43 and 74 GW of onshore wind, which is of the same order of magnitude for a country 15x larger. At the global level, according to the International Energy Agency, wind will have to produce more than a quarter of electricity!
Whether we like it or not, if we look at the facts, it seems impossible – at least in the short/medium term – to decarbonize without wind at our latitudes, and more broadly at the global level.
However, the European sector, world leader, is currently in great difficulty (rising raw material and capital prices, procedural obstacles and delays, supply chain in crisis). This is noted in particular by the IEA in its technology risk matrix for the transition (see slideshow). Chinese competition is desperate to grab the market as was the case for photovoltaics. But Europe will surely want to support its industry - financially or regulatorily - to avoid the same situation...
Bundesamt für Energie (BFE). (2016), Studie über die Migrationsintensität von Vögeln und die Anzahl der Kollisionen in der Nähe von Windkraftanlagen am Standort Peuchapatte (JU), https://www.admin.ch/gov/de/start/dokumentation/medienmitteilungen.msg-id-64688.html
International Energy Agency (IEA). Global Energy & Climate Model: Net Zero Emissions by 2050 Scenario (NZE). https://www.iea.org/reports/global-energy-and-climate-model/net-zero-emissions-by-2050-scenario-nze
Intergovernmental Panel on Climate Change (IPCC). (2018). IPCC WGIII AR5 Annex II: Metrics and Methodology. https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-ii.pdf
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Schwarz, M., Jain, P., & Schaffner, C. (2022). A quantitative assessment of the Axpo Power Switcher. ETH Zurich Energy Science Center. https://powerswitcher.axpo.com/resources/202205_Final%20Report_A%20quantitative%20assessment%20of%20the%20Axpo%20Power%20Switcher.pdf
Swiss Energy Charts. Swiss Energy Charts. https://www.energy-charts.info
United Nations Economic Commission for Europe (UNECE). (2021). Life Cycle Assessment of Electricity Generation Options: Etude multicritère pondérée. https://unece.org/sed/documents/2021/10/reports/life-cycle-assessment-electricity-generation-options
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