Quiz of the Day
Wind & Renewable Energy
Monday, 15 June 2026
Global Wind Day — wind power, renewable energy, weather science
1. What converts wind energy into electricity?
- Geothermal plant
- Solar panel
- Hydroelectric dam
- Wind turbine
Modern wind turbines can stand over 260 metres tall — taller than the Eiffel Tower's main structure. A single rotation of a large offshore turbine blade can generate enough electricity to power a home for about two days. The blades can spin at tip speeds exceeding 300 km/h.
2. Which country generates the highest percentage of its electricity from wind power?
- United States
- China
- Denmark
- Germany
Denmark generates over 50% of its electricity from wind power, more than any other country by proportion. On particularly windy days, Denmark produces more wind energy than it can use and exports the surplus to neighbouring countries. Denmark aims to be completely independent of fossil fuels by 2050.
3. What is the Beaufort Scale used to measure?
- Earthquake intensity
- Atmospheric pressure
- Wind speed and force
- Air temperature
The Beaufort Scale was created by Irish Royal Navy officer Sir Francis Beaufort in 1805. It ranges from 0 (calm, smoke rises vertically) to 12 (hurricane force). Originally it described the effect of wind on a ship's sails. Force 12 was defined as 'that which no canvas could withstand'.
4. What causes wind to blow?
- Ocean currents pushing air
- The Moon's gravitational pull
- The Earth's rotation alone
- Unequal heating of the Earth's surface creating pressure differences
The Sun heats the Earth unevenly — equatorial regions receive more energy than the poles, and land heats faster than water. This creates pressure differences, and air flows from high to low pressure areas, creating wind. The Coriolis effect from Earth's rotation then curves these winds, creating the prevailing wind patterns we observe.
5. What are the traditional Dutch windmills primarily famous for?
- Generating electricity
- Heating homes
- Powering factories
- Pumping water to drain land and grinding grain
The Netherlands once had over 10,000 windmills. They were essential for pumping water out of low-lying polders — without them, about a third of the Netherlands would be underwater. The Kinderdijk windmill network, built in 1740, is now a UNESCO World Heritage Site. About 1,200 historic windmills still stand today.
6. What is an offshore wind farm?
- A wind farm on a mountain
- A wind farm in a foreign country
- A decommissioned wind facility
- A group of wind turbines built in bodies of water
The world's first offshore wind farm was built at Vindeby, Denmark in 1991 with just 11 turbines. Today, the Hornsea projects off England's Yorkshire coast are among the world's largest, with hundreds of turbines covering areas larger than some cities. Offshore winds are stronger and more consistent than onshore winds.
7. What is the fastest wind speed ever recorded on Earth's surface?
- 253 km/h
- 408 km/h
- 512 km/h
- 372 km/h
The fastest reliably recorded surface wind speed was 408 km/h (253 mph) during a tornado in Bridge Creek, Oklahoma in 1999. For non-tornado winds, the record is 372 km/h on Barrow Island, Australia during Cyclone Olivia in 1996. Mount Washington in New Hampshire held the record for 62 years at 372 km/h before being surpassed.
8. What percentage of global electricity did wind power supply by the mid-2020s?
- About 15%
- About 2%
- About 7-8%
- About 25%
Wind power has grown from virtually zero in the 1990s to supplying about 7-8% of global electricity. The cost of wind energy has dropped by over 70% since 2009, making it one of the cheapest sources of new electricity in many regions. Global installed wind capacity has doubled roughly every five years.
9. What is a 'wind rose' diagram used for?
- Showing the frequency and direction of wind at a location
- Measuring wind turbine efficiency
- Decorating weather stations
- Predicting hurricanes
Wind rose diagrams display the distribution of wind speed and direction at a specific location, with 'petals' showing how often wind blows from each direction. They are essential for siting wind farms — placing turbines where wind is most frequent and strong. The concept dates back to ancient Greek and Roman navigation charts.
10. What is the Coriolis effect?
- Hot air rising and cold air sinking
- Wind tunnelling between buildings
- The deflection of moving objects caused by Earth's rotation
- Wind speeding up over water
Named after French mathematician Gaspard-Gustave de Coriolis in 1835, this effect causes winds to curve right in the Northern Hemisphere and left in the Southern Hemisphere. It is responsible for the rotation of cyclones and trade wind patterns. Contrary to popular belief, it does not noticeably affect the direction water swirls in your bathtub — that is too small a scale.
11. Which country has the largest installed wind power capacity in the world?
- Germany
- United States
- China
- India
China has more installed wind power capacity than the next three countries combined. It added more wind capacity in 2020 alone than the entire installed capacity of the United Kingdom. China manufactures most of the world's wind turbines and has some of the world's largest wind farms in its western provinces, including the Gansu Wind Farm complex.
12. What are the jet streams?
- Streams of solar wind hitting Earth
- Narrow bands of strong high-altitude winds
- Ocean currents that affect wind patterns
- Exhaust trails from aircraft
Jet streams are fast-flowing air currents at 9-16 km altitude that can reach speeds of 400 km/h. They were discovered by Japanese meteorologist Wasaburo Oishi in the 1920s using weather balloons. Flights from the US to Europe are often 30-60 minutes faster than the return trip because aircraft ride the jet stream eastward.
13. What renewable energy source produces the most electricity globally?
- Geothermal
- Solar
- Wind
- Hydropower
Hydropower generates about 15% of global electricity, making it the largest renewable source. However, wind and solar are the fastest-growing. Combined, renewables now produce over 30% of global electricity. Many experts predict that wind and solar together will overtake hydropower within the next decade.
14. What is a 'wind shear'?
- The cutting action of turbine blades
- Erosion caused by wind
- A sudden change in wind speed or direction over a short distance
- The sound wind makes through turbines
Wind shear is extremely dangerous for aircraft, particularly during takeoff and landing. It was responsible for several major plane crashes in the 1970s and 1980s, leading to the development of onboard wind shear detection systems. Today, all commercial airports use Doppler radar to detect wind shear and warn pilots.
15. What is a 'capacity factor' for a wind turbine?
- The ratio of actual output to maximum possible output over time
- The maximum power it can produce
- How many homes it can power
- The size of its generator
Wind turbines typically have capacity factors of 25-45%, meaning they produce that percentage of their maximum rated output over a year. This is not inefficiency — it reflects the fact that wind does not blow at full strength constantly. Offshore turbines achieve higher capacity factors because sea winds are stronger and steadier. The best sites now exceed 50%.