P3 Energy Resources Flashcards
What are our energy demands mostly met by
Oil,coal and gas
The percentage of each energy used globally
Oil-31%
Coal-31%
Gas-28%
Nuclear-4%
Hydroelectricity-7%
Other renewables-3%
Energy resources-notes
-Energy resources are large stores of energy that can be used to generate electricity and heat homes and businesses
- a turbine,is turned which turns generator which generates electricity
How does water generate elctricity
-water can be used to turn turbines in the case of hydroelectric dams,tidal barrages and tidal turbines
-energy in kinetic store of flowing water is transferred to kinetic store of turbine and then to kinetic store of generator and transferred electrically to National Grid
Inside a power station
-fossil fuels can be combusted to heat water, and the steam produced can be used to turn turbines
-energy from chemical store of the fuel is transferred to thermal store of water,which is then transferred to kinetic store of turbine and then transferred to kinetic store of generator then transferred electrically to National Grid
Biofuels
-plant matter,ethanol or methane can be produced and used as a fuel in place of fossil fuels.
-biofuel is any fuel taken from a living or recently living organism
-renewable as its biological source either regrows or is continually produced. This means that it is used at same rate that it is replaced.
-carbon-neutral because the carbon that the living organism takes in from atmosphere as carbon dioxide can balance amount that is released when biofuel burnt.
-some regions, large areas of forest have been cleared to make room to grow biofuels resulting in lose of habitat. Decay and burning of vegetation also increases CO2 and methane emissions
Nuclear power
-Nuclear fuel takes energy from atoms. Every atom contains positively charged nucleus with electrons surrounded.
- the fuel in a nuclear power station is uranium. Energy is transferred from nucleus when this happens. Because there is a lot of uranium atoms in core, it becomes very hot
- the energy of core is transferred by a fluid (coolant) that is pumped through core.
- coolant is very hot when it leaves core. It flows through a pipe to heat exchanger then back to reactor core
-energy transferred by coolant is used to turn water into steam in heat exchange. Steam drives turbine that turn electricity generators
-not renewable
-used fuel rods contain radioactive waste
-explosion in reactor could release radioactive material over a wide area.
Wind power
The force of wind drives the turbines blades around. This turns a generator. The power generated increases as the wind increases. Wind turbines are unreliable because when there is little or no wind they do not generate electricity.
-no pollution
-do spoil the view
-very noisy
- no power when wind stops and impossible to increase supply when extra demand
-initial costs are high
-no permanent damage to the landscape-when turbine removed, noise removed and view returns to normal
Wave power
-uses the waves to make floating generator move up and down. The motion turns the generator so it generates electricity. A cable between the generator and the shoreline delivers electricity to the grid system.
-need to withstand storms and don’t produce a constant supply of electricity.
-tidal flow patterns might change affecting marine life and birds
-no pollution
-fairly unreliable
-initial costs are high but no fuel costs and running costs.
-doesn’t provide energy on large scale
Hydroelectric power
Water is collected at reservoir or at height, and when released,rushing water turns turbine directly to generate electricity.
-no pollution
-impact on environment due to flooding of valley and possible habitat loss.
-unsightly look when dry up
-reduces impacts on humans if in remote places
-can provide immediate response to increased demand of electricity .
-no problems in reliability except in times in drought
-initial costs are high,no fuel and minimal running costs
-useful to generate electricity in small scale to remote areas
Tidal power
- the movement of water due to tides turn turbines directly to generate electricity in big dams across estuaries.
-no pollution
-problems in preventing free access by boats,spoiling view and altering habitats
-tides are reliable
-initial costs are moderately high but no fuel costs and minimal running costs.
-generates significant amount of energy
Solar energy
Solar cells use light to generate electricity, solar panel,s use thermal radiation to heat water to produce warm water for household
The water in the tank is turned to steam by heating effect of the solar radiation directed at the water tank. The steam is piped down to ground level, where it turns electricity generators. The mirrors are controlled by a computer so that they track the sun
-produces no greenhouse gases or pollution
-good for producing energy in remote places
-in sunny countries-very reliable resource of energy
-initial costs are high bu after the energy is free and running costs are almost nil
-not reliable as only works in sunny weather and lots are needed
-solar farms can use up a lot of farmland
-used in relatively small scale
-often not practical or too expensive to connect them to national grid
Geothermal energy
-Hot rocks underground are used yo heat water to produce steam to turbines which generate electricity
Geothermal stations fan be built in volcanic areas or where hot rocks below surface. Water gets pumped down to these rocks to produce steam. Then the steam produced drives electricity turbines at ground level
-reliable
-geothermal stations are small
-some places geothermal heat is used to heat buildings directly without need of electrical energy
-Can result in release of harmful gases from undergound
-not many places are suitable
-cost of power plant is high compared to amount of energy we can get out
Fossil fuels
Fossil fuels are combusted to heat water to produce steam to turn turbines to generate elelctricity
The fossil fuels are burnt in boiler to convert its chemical energy to thermal energy. Heat energy is used ti heat water to produce steam. The steam turns a turbine, converting heat energy to kinetic energy. The turbine is connected ti generator, which transfers kinetic energy to electrical energy
-reliable
-can produce large amounts of energy at fairly short notice
-produces significant amount of greenhouse gases and pollution
-causing global warming and climate change
-produces sulphur dioxide which causes acid rain
- non-renewable so will eventually run out
Carbon capture reducing the impact of carbon dioxide
-carbon capture and storage is used to reduce the amount of CO2, building up in the atmosphere and reduce the strength of the greenhouse gas effect
-CCS worms by collecting CO2, from power stations before it is released to atmosphere
-then pumped into empty gas fields and oil fields which can be safely stored without adding to greenhouse gas effect
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Difference between reliable and non-relaibel resoruces
Reliable energy resources is one that produce energy at any time
Non-reliable resources can only produce energy some of the time
Renewable resources
A renewable resource- an energy source that is replenished at a faster rate than the rate that it is being used
Renewable resources:
-solar energy
-wind
-biofuel
-hydroelectricity
-geothermal
-tidal
Non renewable:
-fossil fuels
-nuclear fuel
Renewable energy sources and environment
Adavnatage:
-they will never run out because they are always being replenished by natural processes
-they do not produce greenhouse gases or acid rain
-they do not create radioactive waste products
-they can be used when connection to the National Grid is uneconomical. E.g solar cells can be used for road signs and to provide people with electricity in remote areas
Disadvantages:
-renewable resources are not currently able to meet the world demand. So fossil fuels are still needed to provide some of the energy demand
-wind turbines create a whining nouse that can upset people nearby, and people consider them unsightly
-tidal barrages affect river estuaries and the habitats of creatures and plants here
-hydroelectric schemes need large reservoirs of water, which can affect nearby plant and animal life. Habitats are often flooded to create dams
-solar cells need to cover large areas to generate large amounts of power
-some renewable energy resources are not available all the time or can be unreliable
The greenhouse gas effect
-the sun emits rays that enter the Earth’s atmosphere
-the infrared radiation is emitted back from earth’s surface
-some infrared radiation ir reflect back into space
-some infrared radiation is absorbed by Greenhouse Gases and become trapped within the earth’s atmosphere, causing the earth’s average temperature to rise as a result
-the higher the concentration of greenhouse gases, the higher the average temperature
Consequences:
-climate change due to increase in earth temperature
-sea levels will rise as glaciers melt because of high temperatures, causing flooding in low-lying countries
-extinction of species due to destruction of habitats
-migration of species as will move to areas where more habitable
-spread of diseases caused by warmer climate
-loss of habitat
