Physics P1 Generating Electricity f 2.0 / 5 based on 1 rating ? PhysicsElectricityGCSE Created by: PhoebeCreated on: 17-06-12 20:16 4.1 Fuel for Electricity Electricity generators in power stations are driven by turbines Water is heated to produce steam, which drives the turbine Coal, oil and natural gas are burned in fossil fuel power stations Uranium or plutonium is used as fuel in nuclear power stations The nucleus of the atom undergos a process called nuclear fission which releases a lot of energy Much more energy is released by kg from nuclear fuel than from fossil fuels In some gas-fired power stations, hot gases drive the turbine directly A gas-fired turbine may be switched on very quickly 1 of 5 4.2 Energy from wind and water A wind turbine is an electricicty generator on top of a tall tower Waves generate electricity by turning a floating generator Hydroelectricity generators are turned by water running downhill A tidal power stations traps each high tide and uses it to turn generators 2 of 5 4.3 Power from the Sun and Earth Solar cells are flat solid cells that conbert solar energy directly into electricty Solar heating panels use the Sun's radiation to heat water directly Geothermal energy comes from the energy released by radioactive substances deep inside the Earth Water pumped into hot rocks underground produces steam to drive turbines that generate electricity 3 of 5 4.4 Energy and the Environment Fossil fuels produce increased levels of greenhouse gases which could cause global warming Nuclear fuels produce radioactive waste which has to be stored safely for centuries Renewable energy resources can affect plant and animal life 4 of 5 4.5 The National Grid The National Grid is a network of cables and transformers that distribute electricity to our homes from power stations and renewable energy generators Step-up transformers are used to step up power station voltages to the (higher) grid voltage and lower the current Step-down transformers are used to step the grid voltage down to 230 V for use in our homes and increase the current A high grid voltage allows us to reduce the current, therefore reducing energy loss through the cables and making the system more efficient 5 of 5
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