Presentation on theme: "Resources used to Generate Electricity in Australia."— Presentation transcript:
Resources used to Generate Electricity in Australia
Coal-Fired Generation Coal generates around 85% of Australia’s electricity. Australia is the world’s leading coal exporter. Australia has major coal mines in New South Wales, Queensland and Western Australia. Major power plants are located all over Australia. Not environmentally friendly given that burning coal is well known to produce greenhouse gases which are attributed to causing global warming.
1.The coal is made into a fine powder. This increases it’s surface area and means it burns more quickly. 2.A pulverised coal combustion chamber (PCC) blows the powdered coal into a boiler, where it is burnt at high temperatures. 3. There are tubes of water lining the boiler. The water gets converted into steam by the heat energy and hot gases. 4. The high pressure steam is then shot into a turbine, which contains thousands of propeller like blades. Obviously, the steam pushes these blades, which makes the turbine shaft rotate at high speed.
At the other end of the turbine shaft, there is a generator with carefully wound wire coils which generate electricity when rapidly rotated in a strong magnetic field. After passing through the turbine, the steam is condensed and returned to the boiler to be heated again. The electricity generated is transformed into higher voltages (up to 400, 000) which makes it more economic and efficient to travel along power line grids. When the electricity reaches the point of consumption, it is transformed into the appropriate volts.
Quantities Australia consumes around 230 million tonnes of coal each year – it exports a lot more. On average, a tonne of coal produces gigajoules of energy.
Hydro-Electric Generation Approximately 10% of Australia’s electricity is produced using this method of generation. It is environmentally friendly – leaving no waste and being renewable.
A hydroelectric power plant converts the kinetic energy contained in falling water into electricity. 1.Plants are generally built on a dam to raise the water level and create the drop needed. The water falls through the control gate because of gravity and spins turbines. 2.The turbine is connected to a generator; it’s electromagnets spin in it’s wire coil which creates a flow of electrons. This method is, in a way, similar to using coal. Both methods involve using the energy to spin the wire coil of a generator.
Quantities A big advantage of hydroelectric electricity generation is that it is not actually “using” the water. It’s just harnessing it’s kinetic energy. All the water used is returned to the river. The amount of electricity generated depends on the volume of water and the height of the water above the turbine (more kinetic energy the higher above the turbine it is).
Comparisons Solar Power Advantages: - Renewable - Little maintenance - Solar cells make absolutely - No pollution - no noise at all - Easy to install - Economic savings in the long run Disadvantages: - Expensive upfront - Relies on the weather (night time?!?) - Relatively inefficient -Hard to store
Coal-Fired Generation Advantages: -Affordable -Reliable (continuous and predictable) -Fairly efficient -Low capital investment -Low maintenance -Big industrial base Disadvantages: -Non renewable -Pollution -Acid rain -Mining can be dangerous -Devastation of earth and scenery for new mines
Conclusion I think that although solar power is less reliable than coal-fired generation, it is the better option. It is renewable and environmentally friendly. We’re not going to have a choice over whether to keep using coal because it’s going to run out some day.