- Created by: j_eshun
- Created on: 23-04-15 18:36
Fossil Fuels- the fossil fuels are coal, oil and natural gas. They are formed from the remaikns of organisms that lived millions and millions of years ago. They are non-renewable but release heat energy when they are burnt. In the uk 3/4 of all the electricity generarated come fromm power stations powered by fossil fuel
Disadvantages of fossil fuels
-Fossil fuels are non-renweable, meaning if we don't stop using them they will run out and we wont be able to get them back. materials such as wood are renewable as we can plant trees over and over again, a;lthnough that leads to another topic of deforestations.
-when oil and coal are burned they release sulphur dioxide which is harmful as it contributes to acid rain and breathing difficulties/problems for living creatures.
-They release carbon dioxide when they burn which means its released into the amosphere. this leads to global warming, the greenhouse effect, and so on and so forth. Coal releases the most whereas natural gas releases the least.
Carbon captuere- is technology that sepearts carbon diioxide from waste gases. The CO2 is stored nder the sea
The main nuclear fuels are plutonium and uranium, which are radioactive metals.We do not burn them to release their energy but instead, nuclear fission occurs and the nuclear fuels release their heat energy. After that its exactly identical to the process of generating electricity when we burn fossil fuels.
-It doesnt produce sulphur oxide or carbon dioxide
- If there were an accident, laarge amounts of radioactive material culd be released which can be bad for our health for thousands of years. So it must be stored safely.
Wind energy is renewable because of the sun and it will be renewable, because as long as the sun exists so will wind. The convection currents in the earth's atmosphere drive heat energy away from the sun.Windd turbines have big blades that rest on a large tower, the blades are connected to the nacelle which has everything in it for the generator such as the gears. The wind transfers some of its kinetic energy which causes the blades to spin round, and drive the generator. Wind farms are lots of turbines grouped together in a windy place.
- It is renewable
-No harmful polluting gases are produced and there are no fuel costs
-noisy and unpleasant to the eye
- if there is now wind no electricity is generated
Wave machines use the kinetic movement, of the water in the sea rising and falling because of the waves on the surface, to drive electricity generators.
Tidal barriers are barrers built over a river estuaries to use the kinetic energy of the water moving in and outf the river mouths diue to the tides.The barrage has electricity generators which work by te water rushing through tubes in the barrage.
Hydroelectrical power atations use kinetic energy from the moving water. The water comes from a behind a dam built across the river valley. The water higher up contains gravitational potential energy. this is then transferred into kinetic energy as the water rushes down the tubes of the dam. the water drives the generator.
Advantages and Disadvantages of water energy
-its a renewable source of energy which doesnt run on any fuel costs
-No harmful gases are produced
-Reliable and is switched on easily
-Tidal barriers cause habitat loss for the estuary species
-hydroelectricity dams flood farmland and homes
-Rotting vegetation from underground releases methane, a greenhouse gas
Geothermal energy- hot water and steam, deep deep deep underground can drive turbines
Some rocks contain radiolactive substances such as uranium. The radioactive decay of these substance release heat energy which arms up rocks. In some volcaninc areas the heat can warm up water. The steam can rise up and turn turbines and drive generators
Sometimes the rock is hot but steam and hot water do not rise to thne surface. So cold water is pumped down. The hot rocks heat up the water and so the steam and hot water rise up to the surface. It turns turbines and drives electricity generators.
-Renewable source of energy
-No fuel costs
-No harmful gases are produced
-Most parts of the world dont have a suitable place to use geothermal energy
Solar cells convert light energy straight into electrical energy. Whereas solar panels use heat from the sun to heat up water.
-Doesnt release polluting gases
-Provide electricity to remote locations like roadside signs
-They dont work during the night
-Expensive and inefficient, the price doesnt match the amount of energy
Power stations are reliable sources of energy. They are powered fossil fuels or nuclear fuels. They provide power when needed. Gad fired stations have the shortest start-up time, whereas nuclear power stations have the longest start up time.
Nuclear power stations and coal-fired stations provide base-load electricity wich run continuosly as they take long to start up. Whereas gas-fired and -oil-fired are put up at peak times as they have the least start up time.
Fuel for nuclear power stations are cheap (proportionally), but are made expensive because they are expensive to build, but also dismantle to store radioactive waste.
Renewable sources are free but the equipment used for generating may be expensive. Solar, and wind energy are less reliable as the weather is unreliable. However water energy is more reliable
The Natural Grid
The Natural Grid provides energy from power stations to supply the country's electricity, depending upon local demand.
Transformers- an electrical device that changes the voltage of AC supply
Electricity is sent to consumers from power stations the wires and cables from the National Grid. When the current goes through a wire some energy is lost through heat. Meaning the higher the current the more heat loss. So the Ntaional grid transmits electricity at a low current. Therefore it needs a higher voltage.
A transformer that increases the voltage is a step up transformer. One that decreases the voltage is a step down transforme.