19.08.2022 | Test your energy knowledge

When wind becomes electricity

Wind power is a renewable source of energy that’s strategically valuable in Switzerland since it can be generated in winter. The Swiss Federal Energy Strategy 2050+ sets the target of 4.3 TWh electricity production from wind power by 2050. Is that realistic? We’ve put together a few facts and figures on the subjects of wind power in Switzerland and generating electricity from onshore and offshore wind turbines. Put your knowledge to the test here.

 

1. What percentage of Swiss electricity production does wind power currently account for?

A)    Just under 10%

B)    Just under 5%

C)    Less than 1%

C – Less than 1 %

According to statistics published by the Swiss Federal Office of Energy (SFOE), 146 GWh of electricity in total were generated from wind power in Switzerland in 2020. This covers the consumption of 40,000 Swiss households, or accounts for 0.2% of all electricity produced in Switzerland (c.f. Suisse éole). 

2. How many wind turbines are there in Switzerland at present?

A)    41

B)    87

C)    248

A – 41

There are currently 41 wind turbines in Switzerland, with an installed capacity of 87 MW. The largest wind farm is located on Mont Crosin in the Bernese Jura near St. Imier. There are 16 wind turbines there, with a total capacity of 37.2 MW. Other large-scale wind farms are located in the Rhone Valley (in the canton of Valais), near Entlebuch (in the canton of Lucerne) and on Gütsch (above Andermatt, in the canton of Uri). Axpo’s only wind turbine in Switzerland at present is located in Entlebuch. It is operated by Axpo’s subsidiary CKW. Together with CKW, Axpo is planning six additional wind farm projects in Central Switzerland and in the canton of Aargau. Some 20 turbines will someday produce clean electricity for over 30,000 households. 

CKW’s ‘Lutersarni’ wind turbine in Entlebuch is the largest of three wind turbines in Central Switzerland

3. When was wind power first put to commercial use in Switzerland?

A)    1964

B)    1986

C)    1989

B – 1986

Switzerland’s first wind turbine was commissioned in 1986 near Soolhof (Langenbruck) with a capacity of 28 kW. It was run by Ökozentrum Langenbruck, a non-profit eco-centre. 

4. How tall are onshore wind turbines on average?

A)    40 to 70 metres

B)    120 to 180 metres

C)    Over 200 metres

C – Over 200 metres

Onshore wind turbines can be over 200 metres tall from the ground to the hub – or even taller if you include the rotor blades. You can see what exactly a wind turbine looks like in this video.

The rotor blades of onshore wind turbines can be as large as a football field.

5. The Swiss federal government is keen to promote intense growth in Switzerland’s wind power capacity in line with the Swiss Federal Energy Strategy 2050+. How much electricity should wind power account for in 2050, according to this strategy?

A)    630 GWh

B)    2,300 GWh

C)    4,300 GWh

C – 4,300 GWh

You were definitely paying attention when reading the introduction to this quiz. According to the SFOE, there is potential for strong growth in wind power capacity in Switzerland. By 2030, it is expected that wind turbines will produce around 600 GWh of electricity per year. The aim is to increase this figure to 4,300 GWh by 2050 (c.f. SFOE Energy Prospects 2050+). There are suitable sites on the Jura mountains, not to mention in the Alps and pre-Alpine areas and on the western Swiss Plateau. 

6. What is the optimum wind speed for a wind turbine to achieve maximum capacity?

A)    8 to 10 m/s

B)    12 to 15 m/s

C)    20 to 25 m/s

B – 12 to 15 m/s

Wind turbines harness the airflow’s kinetic energy. Modern wind turbines consist of the mast, the nacelle (which protects the mechanical equipment) and the rotor (usually with three rotor blades). These blades start rotating from a wind speed of 2 metres per second (m/s). A wind turbine produces electricity from 4 m/s. Maximum capacity is reached at 12 to 15 m/s (c.f. Suisse éole). Wind turbines are usually shut down during storms to prevent damage. Rotor blade tips can reach speeds of over 200 km/h. How much electricity is produced depends on the wind speed (electricity production proportionate to the wind speed cubed). If the wind speed is doubled, 23 (i.e. eight times) as much energy is produced. 

7. How long can a wind turbine produce electricity for (what is its service life)?

A)    Between 10 and 15 years

B)    Between 20 and 25 years

C)    Between 30 and 35 years

B – Between 20 and 25 years

A wind turbine can generate electricity for roughly 20 to 25 years before it needs to be replaced by a new one (c.f. Axpo).

In modern wind turbines, almost all the components (including the tower) are made of steel. The only exception is the rotor blades, which are usually made of fibre-reinforced plastics. The service life of steel is very easy to calculate. A wind turbine’s service life also depends on the average strength of the wind it is exposed to. You can find out how a wind turbine is built here.

However, a wind turbine’s service life can be extended. This is known as ‘repowering’ and means that technologically outdated wind turbines are replaced by more powerful ones. This makes better use of sites that are already available. Other advantages include the fact that more electricity can be generated using fewer turbines, with significantly less noise pollution compared to older turbines (c.f. Suisse éole).

What is the difference between onshore and offshore wind turbines? Offshore wind turbines are located in the sea and are making an increasingly important contribution to the energy transition. Offshore wind power refers to electricity generation by wind turbines at sea. More electricity can be generated offshore because the wind speed at sea is more constant than with onshore wind turbines on dry land.

8. How much more electricity does an offshore wind turbine produce compared to an onshore one? 

A)    Twice as much

B)    Three times as much

C)    Four times as much

A – Twice as much

Offshore wind farms can produce twice as much electricity as onshore ones. This makes them extremely reliable when it comes to electricity generation. Offshore wind turbines produce eco-friendly electricity for more than 90% of the year, making them a source of renewable energy (c.f. German Offshore Wind Energy Foundation).

Axpo’s Global Tech I offshore wind farm is located off the North Sea coast in the German Bight.

9. Which European country uses the most wind power to cover its energy needs?

A)    Germany

B)    Denmark

C)    Portugal

B – Denmark

In 2022, wind power production accounted for 16% of all electricity consumption in Europe (c.f. Wind Europe). In 2022, wind power had a 48% share of the electricity mix in Denmark (the EU’s leading wind power nation), followed by Ireland (38%), Germany (27%), Portugal (24%) and Spain (22%). Incidentally, the countries that dominate the global wind power market are China, the USA, Germany, India, Spain/Portugal and the United Kingdom. As is the case with solar power, China is the most important market. The highest growth rates are currently being recorded in Asia.

10. The Beaufort scale is used to measure wind speed. How many classes are there?

A)    8

B)    13

C)    15

B – 13

The Beaufort scale (Bft) is a scale used to split wind speed into 13 classes from 0 (Calm) to 12 (Hurricane) (Hurricane). It is not based on exact measurements, but rather on the observed effects of the wind. It is named after Sir Francis Beaufort (1774 – 1857) and is widely used to describe wind speed. For your information: 6 is described as a strong breeze, 7 as a near gale and 8 as a gale. 

8-10 correct answers

Tornado: Wind is more than just a moving air mass to you. Your knowledge of wind power is superb. That’s something you can be proud of!

 

4-7 correct answers

Windbreaker: Your knowledge is like the wind. Unfortunately, the wind isn’t always strong and tempestuous. Sometimes there’s simply none at all. Your answers were just as mixed. Would you like to change that? Then find out about renewable energy and wind power here.

 

1-3 correct answers

Tea-light: It would appear that all your knowledge on the subject was blown away by the 13 classes of the Beaufort scale and the light went out. Surely you can do better than that? You can find information about renewable energy and wind power here.

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