Energy Sources

Date: 2015-10-07; view: 491.

UNIT 3. Energy sources and problems of survival in post-industrial society

Work in pairs or small groups. Discuss the following questions. Sum up your partner's answers.

1. How long does your weekend last? You always look forward to it, don't you? Where do you and your family normally spend the weekends? Do you spend your weekends quietly at home or do you prefer to go away for the weekend? Do you think people who stay at home at the weekend manage to relax?

2. How often do you go out? Do you go out on weekdays as often as at the weekend? What is your idea of going out? Why do you prefer to go to parties (to the movies, etc.)?

3. Do you manage to relax at the weekend? Your weekends are very busy sometimes, aren't they? Do you try to help your family with the housework at the weekend? What odd jobs do you do about the house? Do you manage to catch up with all the jobs you were too busy to do during the week? Do you at least try?

4. Who does the shopping in your family? How often do you go shopping? What is the busiest time for shopping? Do you prefer to go shopping on weekdays or at the weekend? Which do you think is the most convenient time for shopping?

5. Imagine that you've got a lot of money. What sort of thing would you like to buy or where would you like to go?

TEXT 1

In technologically advanced societies, the enormous consumption of energy per head is one aspect of the ever-increasing pressure man is placing on his environment. Early industrial man used three times as much energy as his agricultural ancestor; modern man is using three times as much as his industrial ancestor. If present trends continue, the rate of consumption will have tripled again by the end of the century. The problem lies in the fact that most of our current energy sources are finite. The hard truth is that a day will come when there is little or no exploitable coal, oil or natural gas anywhere. The sharp rise in the price of oil over the last decade has been unpleasant for many parts of the world but in the long run it is beneficial, partly because it discourages waste and partly because it has forced many nations to seek ways of developing better and more permanent sources of energy.

Energy sources may initially be divided into two kinds: non-renewable (i.e. finite) and renewable. The former group includes coal, oil, gas and, in the long run, nuclear; the latter hydropower, solar power and wind power. The energy from all these sources ultimately derives from the sun. There is a further source – geothermal – which depends on the earth's own heat. In practice this may be classed as non-renewable as it is exploitable in only a few places and even there is limited.

Energy sources may be compared from several points of view:

a) renewability

b) availability. Some energy sources may be excellent from some points of view but unlikely to contribute much at any time because of their limited geographical availability.

c) Cost and efficiency. Some sources may be cheap but highly inefficient, even to a point where they are not practicable. Coal, for instance, though certainly practicable and comparatively cheap, is not very efficient( the efficiency even of a modern power station is only 35%). Geothermal sources, though in a sense free, would, in order to be maintained, end up by using more energy than they produced. Others, like oil, may be comparatively efficient but are in danger of becoming prohibitively expensive.