Generating Electricity Noadswood Science, 2011

Generating Electricity Wednesday, April 19, 2017 To understand how electricity can be generated

Energy Observe the kettle boiling – what energy transfer is taking place? How can we utilise the energy from the kettle to produce electricity?

Energy When the kettle boils there are energy transfers which take place: - Electrical energy is transferred to heat energy Heat energy is transferred to kinetic energy of the water particles within the kettle *Some energy is lost to the surroundings (such as sound energy) We can utilise this kinetic energy of the particles to produce electricity – for this we need a generator…

Power Electricity is a very convenient form of energy that can be generated using different energy resources - some of these resources are renewable and some are non-renewable: - Fossil fuels (natural gas, oil and coal) Nuclear fuels (uranium and plutonium via nuclear fission) Wind energy Water energy (tidal and hydroelectric) Geothermal Solar

Electricity Electricity is supplied to consumers through the National Grid at a very high voltage to reduce energy losses during transmission Transformers are used to increase or decrease the voltage of the supply Electricity is charged in units - one unit is equivalent to one kilowatt of electricity used for one hour The energy needed to boil the water comes from fossil fuels or nuclear fuels. Renewable energy resources such as wind and wave power may drive the generators directly

Electricity Most of the electricity we use is generated from non-renewable sources of energy (coal, oil, gas and nuclear) which are burnt in a boiler releasing heat energy This heats up water, changing it to high pressure steam This steam drives turbines which are attached to a generator which spins around producing electricity

Power Stations Heat is released from fuel, boiling water to make steam Steam turns the turbines Turbines turn generators, producing electricity The electricity goes to the transformers, producing the correct voltage

Electricity Generation Generators are the devices that transfer kinetic energy into electrical energy. They can be turned directly, for example, by: - Wind turbines Hydroelectric turbines Wave and tidal turbines When electricity is generated using wave, wind, tidal or hydroelectric there are two steps: - Turbine turns a generator Electricity is produced Generators can be turned indirectly using fossil or nuclear fuels – heat from the fuel boils water to make steam, which expands and pushes against the blades of a turbine The spinning turbine then turns the generator

Generators Generators induce a current by spinning a coil of wire inside a magnetic field, or by spinning a magnet inside a coil of wire As this happens, a potential difference (voltage) is produced between the ends of the coil, which causes a current to flow One simple example of a generator is the bicycle dynamo

Electricity The rate at which the generator turns affects how much electricity is produced – a bicycle dynamo only produces enough light when you go fast enough – when you stop the magnet within the coil does not turn, and not light is produced

Task Your task is to summarise how electricity is produced and then transferred to our homes This can be done diagrammatically, a 3-D poster, via a flow diagram or as a written journey of the energy…