This GCSE Geography quiz takes a look at wave generators. The demand for energy resources is rising globally but supply can be insecure, for example, conflict in the middle eastern countries could lead to oil shortages. Our traditional energy resources are also finite and at some point in the future, coal, oil, gas and nuclear fuels will no longer be available. The use of fossil fuels as energy resources also releases large quantities of carbon dioxide into the air which may be contributing to global warming. Many industrialised countries have agreed to reduce their carbon footprint.
The impact of these issues has been to promote research into strategies that can increase energy supply and decrease the dependency on the supply of energy resources from outside of a country. The emphasis of this research has been to develop ways of using renewable sources of energy as this helps to solve both problems.
The research is mainly carried carried out by the wealthier countries. The research done in different countries depends on the local resources available. Countries that have high average rainfall and fewer sunny days would be unlikely to research solar power and it would not make sense for a landlocked nation to research wave generators!
In the UK, we are surrounded by sea so developing wave generators to produce electricity could be a good idea. The sea is seldom so calm that there are no waves, but often the weather is so wild that the waves are tens of metres high. This poses a problem for wave generators as they need to be able to survive the most extreme weather but be able to generate electricity even when the sea is quite calm. This illustrates one of the main disadvantages of almost any form of renewable energy - since most of them depend on certain weather conditions, they cannot generate a constant supply of energy.
Anything floating on the sea will bob up and down as the waves pass underneath them. Researchers who are trying to make wave generators rely on this movement to generate electricity. Off-shore wave generators are designed to be anchored out at sea, a little way off the coast. They consist of lines of floats (sometimes called 'ducks') that are all connected to a shaft. The floats move up and down as the waves pass, turning the shaft which turns a generator, producing the electricity. A small on-shore wave generator has been invented, but building these on a useful scale would harm the environment in several different ways.
Unfortunately, there are many disadvantages to wave power that need to be solved before wave generators can be used on anything other than a small scale. There is a lot of energy in the sea but it isn't easy to harvest. To produce a lot of electricity would need huge numbers of these floats and that could interfere with the passage of ships and boats. They need to be anchored firmly and it is very possible that the floats could break loose from their moorings and be lost or pose a hazard to shipping. A lot of research on wave power is carried out in wave tanks. These are like very large scientific swimming pools! Scaling up the wave generators from the models used in these wave tanks is very difficult, the full size versions never seem to produce the expected amounts of electricity.
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