Electrical energy is one subject studied in GCSE Science. This is the fifth of six quizzes on that, topic and it looks at some of the pros and cons of alternative electricity from renewable sources.
Since the start of the Industrial Revolution, an ever increasing proportion of our energy has come from non-renewable sources such as oil, coal and natural gas. These fossil fuels were made millions of years ago from the remains of dead plants and sea creatures. When they are used up, it will take millions of years before any more are formed. They lock away carbon which is then released into the atmosphere when they are burnt. This means that the amount of carbon dioxide in the air has increased since we started using more and more fossil fuels. Our needs for energy continue to rise and these resources are running out. Scientists and engineers are exploring the potential of renewable sources of energy for the future.
These alternatives to fossil fuels are based on wind, waves, running water and the Sun. The earliest renewable energy source was hydroelectric. In the north-east of England, a rich businessman installed a hydroelectric system to provide electricity for his home. Water was collected in a small lake on the hills near where he lived. This was then piped down to turn a turbine connected to a generator, creating a small hydroelectric power station.
As well as solving the problem that fossil fuels won't last forever, renewable alternative methods of generating electricity can help to reduce air pollution, particularly carbon dioxide pollution. This gas is known to contribute to global warming and many people, including scientists, believe that our use of fossil fuels could create a runaway greenhouse effect that could eventually lead to the end of most life on the planet.
There are plenty of pros, or advantages, to renewable energy generation - but there are also some cons, or disadvantages. Take, for example, windfarms. People living close to them complain they are noisy and naturalists claim that they are harmful to wildlife as the noise drives animals away and birds are killed by the rotating blades. There are pros and cons for each and every alternative to fossil fuels. You need to know all of the major issues for the exam.