Science & Technology in Action

10th Edition

Wind Turbine Technology

Siemens

Wind power has been the most rapidly growing form of energy in Ireland over the past ten years; installed capacity has risen from about 600 MW (in 2004) to 2190 MW (in 2014). Wind power is generally greatest in Ireland during winter when the demand is highest − in contrast to solar power.
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Contains the full lesson along with a supporting toolkit, including teachers’ notes.

Lesson excerpt

Context 

Since 1968 the world population has increased from 3.5 billion to over 7 billion. The majority of people live in undeveloped or developing countries. With increasing development comes an increasing demand for energy. There is however growing realisation that the use of fossil fuels has had undesirable consequences and that we need to reduce CO2 emissions. Alternative and more sustainable sources of energy will be increasingly required to meet agreed targets. 

Worldwide, solar and wind power are the most rapidly growing alternative energy sources. The chart shows the rapid growth in installed wind power in the past decade or so. 

Wind power has been the most rapidly growing form of energy in Ireland over the past ten years; installed capacity has risen from about 600 MW (in 2004) to 2190 MW (in 2014). Wind power is generally greatest in Ireland during winter when the demand is highest − in contrast to solar power. 

Since wind is very variable the actual capacity is, on average, about 25% of installed capacity. So although wind power sometimes accounts for over 50% of the country’s immediate electricity needs (roughly 3000 MW ± 1400 MW), wind energy currently accounts for roughly 20% of our total annual electricity (18% in 2013) and about 3.5% of our total annual energy use. The target set by Government is for 40% of the country’s electricity to be derived from renewable resources by 2020. 

Background 
In 1800 Volta invented the battery and it was an immediate sensation. Within months several discoveries were made: the heating effect of electric current, electrolysis and electroplating. However the discovery of the magnetic effect of an electric current was not made until 1820. The first practical electric motors were made in the 1830s but they still depended on batteries. 

What was needed was a practical dynamo, but that development took another thirty years (1866). Further improvements in dynamos and alternators led to the first commercial electricity distribution systems (1879) and electric public lighting (1880s). 

For over 1000 years people have been using wind power to grind grain. Its application to the generation of electricity came in 1887 when the Scottish engineer, James Blyth, built a wind-powered battery charger. 

Quiz questions

  1. In Ireland the electricity demand is around 300 MW. false
  2. Wind energy accounts for 50% of Ireland’s total annual energy needs. false
  3. The first wind-powered electricity generator was built in 1831. false
  4. A kilowatt-hour (kW h) is a measure of energy. true
  5. Volta invented the battery in 1800. true
  6. One kilowatt hour is equal to 36 MJ. false
  7. Direct drive generators generally have fewer poles than geared generators. false
  8. The frequency of the electricity supply in Europe is fifty hertz. true
  9. The output of asynchronous generators is first converted to direct current and then to alternating current to match the frequency and phase of the grid. true
  10. The mass of a cubic metre of air is approximately 12 kg. false
  11. The kinetic energy of one cubic metre of air moving at 10 metres per second is approximately 120 joules. false