Tuesday, 17 February 2015

4d) Energy resources and electricity generation

Energy transfers involved in generating electricity using:
  • Wind: kinetic to electrical 
  • Water: kinetic to electrical by turbines 
  • Geothermal resources: heat from underground 
  • Solar heating systems: light to electrical 
  • Solar cells: transforms light to electrical 
  • Fossil fuels: oil, coal, natural gases and nuclear 
  • Nuclear power: nuclear to heat to kinetic to electrical

Paper Two- Methods of large-scale electricity production from various renewable and non-renewable resources:

+---------------+-------------------------------+----------------------+----------------------+
|               | Summary                       | Advantages           | Disadvantages        |
+---------------+-------------------------------+----------------------+----------------------+
| Hydroelectric | Rivers fill a lake            | Renewable energy     | Few areas of the     |
| energy        | behind a dam. Fast-           | resource             | world suitable       |
|               | flowing water from            | Hydroelectric        | Dams effect the      |
|               | the lake turns generator.     | generating plants    | river ecosystems     |
|               |                               | have a long life     |                      |
+---------------+-------------------------------+----------------------+----------------------+
| Tidal         | A dam built across and        | Renewable energy     | Very expensive       |
| energy        | estuary. A lake behind        | resource             | to set up; few       |
|               | the dam fills up at high      | They are free, re-   | areas suitable       |
|               | tide, and empties at low      | newable and clean    |                      |
|               | tide. Fats-flowing water      | source of energy     |                      |
|               | turns generators.             |                      |                      |
+---------------+-------------------------------+----------------------+----------------------+
| Wave          | Generators are driven         | Renewable energy     | Difficult to build   |
| energy        | up and down motion of         | resource             | successfully         |
|               | waves at sea.                 | Produces clean       |                      |
|               |                               | electricity          |                      |
+---------------+-------------------------------+----------------------+----------------------+
| Solar         | Solar panels absorb the       | Renewable energy     | Continuous sunsh-    |
| energy        | sun's energy to heat          | resource             | ine needed           |
|               | water. Solar cells absorb     | The will always be   |                      |
|               | it and produce                | energy if the sun is |                      |
|               | electricity.                  | there.               |                      |
+---------------+-------------------------------+----------------------+----------------------+
| Nuclear       | Radioactive materials         | Small amounts of     | Fuel is radioactive  |
| energy        | naturally release heat. A     | nuclear fuel give    | Nuclear waste is     |
|               | nuclear reactor speeds up     | large amounts of     | very dangerous       |
|               | the process. The heat is      | energy               |                      |
|               | used to generator             |                      |                      |
|               | electricity.                  |                      |                      |
+---------------+-------------------------------+----------------------+----------------------+
| Geothermal    | Water is heated by the        | Renewable energy     | Deep drilling very   |
| energy        | hot rocks which lie many      | resource             | difficult and        |
|               | miles beneath the Earth's     | High qualities of    | expensive.           |
|               | surface. The heat in the      | energy available     |                      |
|               | rocks comes from radioa-      |                      |                      |
|               | ctive materials naturally     |                      |                      |
|               | present in the Earth.         |                      |                      |
+---------------+-------------------------------+----------------------+----------------------+
| Biomass       | Fast-growing plants, or       | Renewable energy     | Huge land areas      |
| energy        | biomass are used to make      | resource             | needed to grow       |
|               | alcohol is used as fuel, like | Burning biomass      | plants; this may up- |
|               | petrol                        | doesn't harm the     | set the balance of   |
|               |                               | environment          | nature.              |
+---------------+-------------------------------+----------------------+----------------------+

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