Presentation on theme: "Why are we studying this? What are our main energy sources? Do we have enough energy sources?"— Presentation transcript:
Why are we studying this? What are our main energy sources? Do we have enough energy sources?
Glossary words from last lesson Earth’s crust Mineral ore Open-cut mining Underground mining
Fossil fuels Energy is stored in the form of fossil fuels below the Earth’s surface: coal, oil & natural gas – Fossil fuels were once the remains of ancient plants and animals – Formed before the dinosaurs roamed the earth (300 million years ago) Burning fossil fuels converts the stored energy into usable forms E.g. Heat, movement, light Non-renewable resource!
Fossil fuels Coal formed from the remains of dead trees and plants which had fallen into swamps and were unable to rot fully under water Layer of partially rotted plant material: peat Over time the layers of peat built up and then rocks formed on top of them (sedimentary rocks)
Coal The pressure from the rocks above compressed the peat The heat from the Earth’s crust made the peat warmer and drove out most of the remaining water, forming coal Brown coal is young coal, Black coal is produced by longer compression and the driving out of more water. It is harder and drier. Brown coal (lignite) Black coal (anthracite)
Coal mining Major brown coal reserves in Victoria are found in Latrobe Valley More than 80% of Victoria’s electricity is generated here -> what problems are associated with using coal? The coal is close to the surface so open mining is used If it is deeper in the ground underground mining must be used- more expensive & more dangerous
Oil and gas Dead plants and sea animals buried at the bottom of the sea decomposed and were compressed over millions of years Chemical reactions gradually produced oil and natural gas Oil is taken from the Earth’s surface and converted to usable fuels in oil refineries, E.g. Diesel and petrol for cars, kerosene for lamps and camping stoves Gas is also collected and mostly used for heating and to power stoves for cooking
Question 13 on page 243 Think, pair, share Answer this question by yourself: Turn to your friend and discuss your choices and your reasoning – Did you have different reasons for picking the same items? Share with the class
Glossary words covered so far Oil Natural gas Earth’s crust Mineral ore Open-cut mining Underground mining Peat Fossil fuels Brown coal Black coal
Homework: 1. Use your textbook to produce a Glossary containing definitions to all the terms I have given you today. I will be testing your knowledge of these terms next lesson! Plant projects: water your plants, those who are treating plants with something dissolved in water make sure you do this.
Nuclear energy Nuclear energy is produced from metals called uranium or plutonium. renewable or non-renewable?? Energy is produced by a splitting a molecule in two (‘splitting the atom’). This energy is used to produce steam which drives turbines and produces electricity Uranium is radioactive and gives off energy called radiation, radiation sickness in humans can be fatal
Solar energy Solar energy is produced when solar (photovoltaic) cells transform light energy from the sun into electrical energy can be used immediately or stored in a battery In the past solar power stations uses the suns rays to heat up oil, the oil then heats up the water and the steam drives turbines Modern power stations use huge arrays of solar panels to produce energy
Wind power Wind is caused by the sun unevenly heating the Earth and its oceans A single wind turbine can produce enough energy to supply 700 homes, but some people think they are noisy and unsightly Wind can turn a turbine without the need to produce steam or emit carbon dioxide like the fossil fuels Wind energy is renewable
Biomass Dead and rotting plant and animal tissue produces gases such as methane, methanol and oils that can be used as fuels to drive small turbine electricity generators, E.g. Rubbish tips Renewable resource Worm farms process food waste The nutrient-rich fluid produced can be used as fertiliser for gardens
Ocean wave energy The up and down movement of the waves can be used to drive motors that generate electricity Waves are produced by the effect of the wind on the ocean Renewable or non-renewable??
Tidal energy Power stations harness the energy of the rising and falling of the tides Turbines are placed at the entrance of a bay and the water moving in and out of the bay drives the turbines as the tides change Renewable or non-renewable??
Geothermal energy Energy transferred from rocks just below the Earth’s surface is used to produce water from steam, this steam drives turbines in geothermal power stations. In New Zealand, but there has been research to use this technology in Australia.
Hydroelectric power Hydroelectric energy is produced by using falling water to turn turbines and produce electricity Requires a constant source of free flowing water so turbines are often built in high-altitude areas Water is held in Dams and then released to cause free-flowing water which turns turbines
Glossary words covered so far Oil Natural gas Nuclear energy Ocean wave energy Tidal energy Geothermal energy Hydroelectric power Earth’s crust Mineral ore Open-cut mining Underground mining Peat Fossil fuels Brown coal Black coal
Science Quest 7 p.259 Table 1- make table and fill in the answers.