Library Task - Energy
Geothermal
1) Three types of power plants are used to generate power from geothermal energy: dry steam, flash, and binary. Dry steam plants take steam out of fractures in the ground and use it to directly drive a turbine that spins a generator. Flash plants take hot water, usually at temperatures over 200 °C, out of the ground, and allows it to boil as it rises to the surface then separates the steam phase in steam/water separators and then runs the steam through a turbine. In binary plants, the hot water flows through heat exchangers, boiling an organic fluid that spins the turbine. The condensed steam and remaining geothermal fluid from all three types of plants are injected back into the hot rock to pick up more heat.
2) In Australia Geothermal is mainly found in Western Australia and Central Australia, and is relatively accessible. Because it involves obtaining heat from rocks to create energy there are only certain places where the heat is sufficient to generate steam for power. It also means that the rocks used are found between 3 and 4 km below the surface.
Wind
1) Most modern wind power is generated in the form of electricity by converting the rotation of turbine blades into electrical current by means of an electrical generator. In windmills (a much older technology), wind energy is used to turn mechanical machinery to do physical work, such as crushing grain or pumping water.
2) Wind power is very common in Australia because it has proved to be economical and inexpensive form of generating energy for people. There are wind farms located all over Australia, with huge turbines making this type of energy very accessible.
Solar
1) Solar power (also known as solar energy) is the technology of obtaining usable energy from the light of the sun. Solar energy has been used in many traditional technologies for centuries, and has come into widespread use where other power supplies are absent, such as in remote locations and in space. Solar thermal energy can be focused on a heat exchanger, and converted in a heat engine to produce electric power or applied to other industrial processes.
2) While solar technology would be very well suited to our hot dry climate with plenty of sun, it has proved to be an expensive way of generating energy. This is because of the cost of creating panels, making the entire process uneconomical. However, this is expected to change as panel prices come down, Australia could become a large user of this natural resource.