Flashcards
Renewable Energy
Cards in this deck (23)
- 1Energy SourcesPhysics 1b 1.1 - 1.8
- 2Describe what is meant by the term 'renewable source'.They will never run out, most of them do damage to the environment but in a less harmful way than non-renewable sources of energy. They do not provide much energy and some of which are very unreliable.
- 3Describe what is meant by the term 'non-renewable' energy.They will all run out one day, and they all do extensive damage to the environment, however they provide most of our energy.
- 4State the processes of burning non-renewable sources of energy in a power station.1) The fossil fuel is burned to convert its stored chemical energy into heat (thermal) energy.
2) The heat energy is used to heat water to produce steam.
3) The steam turns a turbine. converting heat energy into kinetic energy.
4) The turbine is connected to a generator which transfers kinetic energy into electrical energy. - 5How does 'wind power' work?Each turbine has its own generator, which works by rotating the blades. There is no pollution, however they spoil the landscape and they are nowhere near as efficient as coal-fired power stations. They can also be very noisy which can be particularly annoying for those living within the vicinity. They rely on the weather to function, while the initial cost is very high. There is no permanent damage to the landscape, they can be removed and the noise will stop.
- 6How does 'solar power' work?Solar cells generate electric currents directly from sunlight, this makes them good for small appliances such as a calculator or watch. They are often used in remote places where there is very little choice of anything else, There is no pollution, and in sunny countries they can be very reliable. Initial costa are high but the running cost is very minimal and the energy is free. It is often too expensive to connect them to the National Grid.
- 7How does 'hydroelectricity' work?Rain water is collected behind a dam where it is then allowed out through turbines, therefore there is no pollution. The flooding of a valley has a big effect on the environment (rotting vegetation causes an increase in carbon dioxide and methane) and possible loss of habitat for some species. The reservoirs can also look quite unsightly when the water dries up. Initial costs are high, but there are no running costs and there's is no issue of reliability. They can provide a quick response to an increase in the demand for electricity.
- 8How does 'pumped storage' work?Most large power stations have huge boilers which are kept running through the night, this means that there is a surplus of energy during the night, otherwise there is no way of storing this energy except for pumper storage. Spare energy during the night is used to pump water to a higher reservoir. This water can then be released in order to provide energy when there is a higher demand. This works in the same way as hydroelectricity, however this is just a way of storing energy rather than generating it.
- 9How does 'wave power' work?Small wave-powered turbines are placed along the coast, these are provided with an up and down motion when the wave comes into shore which can be used to drive a generator. There is no pollution, however some believe that they ruin the landscape and are a hazard to boats. They are fairly unreliable as they depend on the wind. Initial costs are high, but there are no fuel costs and minimal running costs. For this reason, wave power is more likely to be used on a larger scale, but it can also be useful on small islands.
- 10How do 'tidal barrages' work?These are big dams built across rivers or estuaries with turbines in them. As the tide comes in, this fills up the estuary behind the dam - it also drives the turbines at a controlled speed. There is no pollution, but the main problems are preventing free access by boats, spoiling the view and altering the habitat of the wildlife. Tides are pretty reliable in the sense that they happen twice a day without fail, however the height of the tide is variable so lower tides will not provide as much energy. When the water height is the same on both sides, the turbines will not work. Initial costs are high but there are no fuel costs and minimal running costs.
- 11How does 'geothermal energy' work?This is only possible in volcanic areas where hot rocks lie fairly close to the surface, the source of energy is the slow decay of various radioactive elements, including uranium. Steam and hot water rise to the surface and are used to drive a generator, therefore there are no environmental problems included. In some places, the geothermal heat energy is used to heat homes, without being converted at all. The main disadvantage is that there are few suitable locations, the cost of building is also very high compared to the amount of energy we can get out of it.
- 12How do 'biofuels' work?These are renewable energy sources which are used to heat up water by burning them. They are also used in cars - just like fossil fuels, they can solids, liquids or gases. We can get biofuels from organisms which are still alive or from dead organic matter. For example, crops like sugar cane can be fermented to produce ethanol or plant oils can be modified to produce biodiesel.
- 13How do 'nuclear reactors' work?This is mostly the same as an ordinary fossil fuel power station but work with nuclear fission of uranium or plutonium producing the heat to make steam to drive the turbines. These take the longest time to start up, whilst natural gas power stations take the shortest time of all fossil fuel power stations.
- 14Discuss the pattern between burning fossil fuels and the levels of carbon dioxide in the atmosphere.Carbon dioxide is released when fossil fuels are burned - for the same amount of energy burned, coal produces the most CO2. All of this carbon dioxide adds to the greenhouse effect and is believed to be one of the causes of global warming.
- 15When coal and oil are burned, sulfur dioxide is released, which causes acid rain - what effect does this have on the environment?This can be harmful to trees and soils, therefore it has an adverse effect on ecosystems. This can be reduced by taking the sulphur impurities out of the raw materials before they are burned, or cleaning up the emissions.
- 16What effect down coal mining have on the environment?This makes a mess of the landscape, especially during 'open cast mining'.
- 17Which environment issue is sometimes caused by the transportation of oil?Oil spills in oceans can have a devastating effect on the environment, such that mammals and fish that live in the area are harmed.
- 18State three of the risks associated with nuclear power.1) The nuclear waste is dangerous and difficult to dispose of.
2) Nuclear fuel is relatively cheap however the overall cost of nuclear power is considerably high due to the cost of power plant and final decommissioning.
3) Nuclear power always carries the risk of major catastrophe, such as the Chernobyl disaster in 1986. - 19Discuss the advantages and disadvantages of biofuels.Advantages: they are supposedly carbon neutral, and are relatively quick to produce. In some regions, large areas of forest have to be cleared before room can be made for the biofuels to be produced. The decay and burning of vegetation also increase CO2 levels and methane emissions.
- 20How does carbon capture and storage (CCS) work?This is used to reduce the amount of CO2 building up in the atmosphere and reduce the effects of the greenhouse effect. CCS works by collecting the CO2 in power stations before it is released into the atmosphere. This CO2 can be pumped into empty gas fields and oil fields. It can be safely stored without adding to the greenhouse effect.
- 21Suggest some alternative ways of storing the carbon dioxide captured during CCS.Dissolving it into sea water and storing it with algae, which can then be used as a biofuel.
- 22Compare the use of a variety of renewable energy sources.See page 52 for more detail.
- 23How is electricity distributed to the homes of the UK?Through the National Grid, it enables energy to be generated anywhere in the grid and then it is supplied to somewhere else. To transmit the huge amount of power needed, you need either a high current or high voltage. When the current is higher, you lose a lot of energy as heat.
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- Flashcards on Renewable Energy, created by Lauren Adams on 24/04/2016.
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- Lauren Adams
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