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KS4 Physics. Energy Resources. Contents. Energy Resources. Types of energy resources. Non-renewable fuels. Electricity from fuels. Comparing fuels. Summary activities. Sources of energy. What are the sources for most of the energy on Earth?.
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KS4 Physics Energy Resources
Contents Energy Resources Types of energy resources Non-renewable fuels Electricity from fuels Comparing fuels Summary activities
Sources of energy What are the sources for most of the energy on Earth? 1. The vast majority of the energy resources on Earth can trace their energy back to the Sun. 2. The Moon is another source of energy. 3. Radioactive elements made in supernova explosions are another source of energy.
Energy resources What energy resources are shown in this scene?
Types of energy resource Renewable Non-renewable There are two types of energy resource: Renewableenergy resources will never run out (at least not for a very long time), or can be regenerated. Examples: w___ and S__. Non-renewable energy resources will eventually run out – once used they cannot be used again. Examples: c___ and o_. ind un oal il
Contents Energy Resources Types of energy resources Non-renewable fuels Electricity from fuels Comparing fuels Summary activities
Fossil fuels What is a fuel? A fuel is a store of (chemical) energy. What is a fossil fuel? A fossil fuel is a fuel formed from the remains of animals and plants over millions of years. Name three fossil fuels: 1. ___________ 2. ___________ 3. ___________ Coal Oil Naturalgas
How coal formed Millions of years ago trees died and fell to the bottom of swamps. Over time they became covered by mud and rock. …the trees became fossilized, forming coal. Over millions of years, due to high temperatures and pressure…
How oil and natural gas formed Millions of years ago plankton died and fell to the bottom of seas and oceans. Over time they became covered by mud and rock. …the plankton became oil and natural gas. Over millions of years, due to high temperatures and pressure…
Nuclear fuels What fuels are used in nuclear power stations? Uranium and plutonium What process releases the nuclear energy? Nuclear fission What are the main advantages of nuclear power? A large amount of energy for a small amount of fuel, no acid rain, no greenhouse effect, cheap to run once built.
Contents Energy Resources Types of energy resources Non-renewable fuels Electricity from fuels Comparing fuels Summary activities
Fossil fuel power stations Fossil fuel power stations convert c______ energy into e______ energy. hemical lectrical Oil and coal fired power stations work in a very similar way. The fuel is burnt and the heat boils water to make high pressure superheated steam, which is used to turn a turbine. Natural gas fired power stations do not use steam. The natural gas is burnt, which produces hot gases that turn the turbine directly.
Nuclear power stations Nuclear power stations convert n_____ energy into e______ energy. uclear lectrical In a nuclear power station the fuel is not burnt; instead it undergoes a fission reaction in the nuclear reactor, which releases heat. Like in a coal fired power station the heat is used to make high pressure steam. What are the energy transfers in a nuclear power station? Generator Turbine Reactor heat kinetic nuclear electrical
Start-up times Power stations cannot just be turned on at the flick of a switch. They need to be started up – this process can take days! The graph below shows the typical start-up times for different types of power station
Contents Energy Resources Types of energy resources Non-renewable fuels Electricity from fuels Comparing fuels Summary activities
Burning fossil fuels What is produced when fossil fuels are burnt? heat energy burn in oxygen ash carbon dioxide sulfur dioxide Fossil fuels are cheap and the heat energy is useful. However, there are problems with burning fossil fuels: • ash is a waste product that needs to be disposed; • carbon dioxide causes the greenhouse effect; • sulfur dioxide causes acid rain.
Global warming arbon ioxide reenhouse lobal ffect arming C_____ d_____ is a greenhouse gas – it lets the Sun’s heat energy into the Earth’s a_________ but it will not let it escape. tmosphere This results in the Earth getting w_____. This effect is called the g e. G w results in the icecaps melting, which could lead to flooding and changing weather patterns. armer
Carbon dioxide from fuels Some fossil fuels release less carbon dioxide when burnt than others. The graph below shows the relative amounts of carbon dioxide released per unit of electricity produced:
Acid rain Burning fossil fuels containing sulfur causes sulfur dioxide to be formed. This gas is released by power stations and mixes with water in the atmosphere to form acid rain. sulfur in coal sulfur dioxide acid rain mixed with water combustion What does acid rain do to the environment? kills trees corrodes buildings and statues kills water life acidifies soil
Reducing acid rain Acid rain is mostly caused by sulfur dioxide (which forms sulfuric acid), but carbon dioxide also contributes (by forming carbonic acid). How can acid rain be reduced? • Burn fewer fossil fuels – generate electricity in other ways. • Remove sulfur from oil and natural gas before it is burnt. • Scrub waste gases to remove sulfur dioxide. • Use expensive coal that contains little sulfur.
Pros and cons of fossil fuels Although there are problems burning fossil fuels in power stations there are also advantages: readily available non-renewable easily transported acid rain low fuel cost greenhouse effect low building costs inefficient short start-up times
Pros and cons of nuclear power Although there are problems in the use of nuclear power, there are also advantages: Cheap to run Expensive to build Conserves fossil fuels Expensive to decommission No sulfur dioxideemissions Radioactive waste No carbon dioxideemissions Links with cancer Safe undernormal conditions Non-renewable Little fuel used meansless transport needed Risk of disaster
Fuel reserves 25-30 about 75 about 300 thousands Even though nuclear fuel will last thousands of year it will still run out eventually. natural gas oil coal nuclear
Contents Energy Resources Types of energy resources Non-renewable fuels Electricity from fuels Comparing fuels Summary activities
Glossary • acid rain – Rainwater that is more acidic than normal because acidic gases have dissolved in it. • fossil fuel –A fuel made from the remains of decayed plants or animals. • generator –A device that transforms kinetic energy intoelectrical energy. • global warming – The increase in the temperature of the Earth, which some scientists think is causing climate change. • greenhouse effect – The trapping of heat from the Sun by certain gases in the Earth’s atmosphere. • non-renewable – An energy source that cannot be used again. • renewable – An energy source that can be regenerated. • turbine –A device that turns heat energy into kinetic energy.
