The picture illustrates the process of electricity manufacture in a hydroelectric power station.
It is clear that the process involves various stages beginning with water flow in high-level reservoir and ending with electricity in power lines to the national grid.
Looking at first step of the process, river water stored in high-level reservoir which is blocked by a dam. Following this, an intake at the bottom of this dam which is opened in day to allows the flow of water to generate electricity and closed at night to the water flows out into the river below the dam during pumping.
In day, water flow to generating electricity by an operate generator in a power station then it is moved in power lines to national grid. By contrast, water from low-level reservoir will be pumped into high-level reservoir during the night to ready for day time activities.
- Many governments think that economic progress is most important goal some people however think that other types of progress and equally important for a country 67
- the plans below show a public park when it was first opened in 1920 and the same park today Summarise the information by selecting and reporting the main features and make comparisons where relevant 78
- The pie charts below show the percentage of water used for different purposes in six areas of the world Summarise the information by selecting and reporting the main features and make comparisons where relevant 73
- At the present time the population of some countries includes a relatively large number of young adults compared with the number of older people Do you think that the advantages of this outweigh the disadvantages 73
- In spite of the advances made in agriculture many people around the world still go hungry Why is this the case What can be done about this problem 81