Physics 1 Revision Lesson 4 Generating electricity Generating

Physics 1 Revision Lesson 4 Generating electricity

Generating electricity power stations and the national grid

Power stations make electrical energy from fossil fuels or nuclear fuel Fuels are burnt in the boiler which releases heat energy This heats water changing it into high pressure steam The steam is used to drive huge turbines (big fans) The turbines are attached to a generator which spins around making electricity Electrical energy is then fed onto the National grid and out to our home - where it powers our TV’s etc

Once electricity is made it must be transported around the country Overland cables Underground cables Over ground cables Under ground cables Cheaper Not safe from weather Safe from weather Expensive Faults can be easily located and quickly repaired Can’t transport electricity over water Can transport electricity under water Faults can’t be easily located and quickly repaired Flexible to adapt to changes in network demand. Eyesore Unseen Not Flexible to adapt to changes in network demand. Prone to short-term interruptions Less disturbance to land than underground installation More reliable Installation causes land disturbance

Electricity is distributed from power stations to consumers along the National Grid The voltage is ‘stepped up’ when it leaves the power station to reduce the current - this reduces the amount of energy loss The voltage is then ‘stepped down’ before it reaches our homes Power station Step up transformer Step down transformer Homes

Generating electricity Non Renewable energy sources

Fossil fuels are found underground and take millions of years to form They are non renewable they cause pollution and global warming Advantages of fossil fuels Disadvantages of fossil fuels Readily available Non renewable Easily transported Causes pollution & acid rain Low fuel cost Causes global warming due to increasing the amount of CO 2 Low building costs Inefficient Short start up times Have to dig to find them

Nuclear fuels use energy from splitting an atom to make electrical energy They don’t produce any pollution They do produce dangerous radioactive waste Advantages of nuclear fuels Disadvantages of nuclear fuels Cheap to run once built Expensive to build Conserves fossil fuels Non renewable No sulphur dioxide emissions Produces radioactive waste No carbon dioxide emissions Expensive to shut down Safe under normal conditions Links with cancer Small amount of fuel used so less transport needed Risks of distaster

Generating electricity Renewable energy sources

Biofuels are made form plants and use the chemical energy in plants to make electrical energy They are cheap They require a lot of land Advantages of Biofuels Disadvantages of Biofuels Low fuel cost Need a lot of space to grow the crops Less pollutants put in the atmosphere Growing bio fuels takes up valuable farm land can lead to a loss of habitats Renewable The fertilisers used to grow biofuel cops can be harmful to the environment Short start up times Vehicles need to be adapted to run on biofuels

Wind turbines use kinetic energy and turn it into electrical energy Advantages wind Disadvantages wind Renewable Needs a lot of space Clean energy- no pollution More than one needed On windy day can produce a lot of electricity Eye sore Can be noisy Expensive to build Needs a windy day to generate electricity

Water can be used to make electricity, by making a turbine spin Wave turbine- use the kinetic energy from waves going up and down Tidal turbines- use the kinetic energy from tides coming in and out of land Hydroelectric dams- use the kinetic energy of falling water These can be used in remote locations were it is difficult to put in electricity cables from a power station

Solar panels may contain water that is heated by radiation from the Sun. This water may then be used to heat buildings or provide domestic hot water Solar panels are often used to make small amounts of energy to light up road signs etc. No pollution Only works on sunny days Cheap once installed Expensive to buy

Geothermal power stations use thermal energy from hot volcanic rocks deep underground to make electrical energy No pollution Expensive to build power station Renewable Eye sore

Key words and statements

Generating electricity Step up transformers Voltage is decreased through this device before the electricity reaches our homes Step down transformers Where different energy forms are converted into electrical energy. Usually via a turbine Power stations Energy sources that will run out one day. National grid Voltage is increased through this device so that current is reduced in order to decrease energy loss through cables Renewable energy sources Increase in temperature due to the increasing levels of carbon dioxide gas. Non renewable energy sources Energy sources that will not run out Global warming Energy that does not produce any pollution or waste Clean energy How energy is distributed to homes from the power station

Generating electricity Step up transformers Voltage is decreased through this device before the electricity reaches our homes Step down transformers Where different energy forms are converted into electrical energy. Usually via a turbine Power stations Energy sources that will run out one day. National grid Voltage is increased through this device so that current is reduced in order to decrease energy loss through cables Renewable energy sources Increase in temperature due to the increasing levels of carbon dioxide gas. Non renewable energy sources Energy sources that will not run out Global warming Energy that does not produce any pollution or waste Clean energy How energy is distributed to homes from the power station

Generating electricity Over ground cables are… Expensive to build and produce radioactive waste but don’t release any pollutant gasses Underground cables are… Cheap but can be affected by weather Fossil fuels are… cheap, and renewable, but they require a lot of valuable land to grow crops on Nuclear fuels are… Expensive to install and will only work on sunny days, but is rebewable Biofuels are… Are more reliable, but faults cant be fixed easily Solar power is… Renewable, but requires a large power station to built on top of volcanic sites which can be an eyesore Geothermal power is… Readily available and can be transported easily, but cause pollution, acid rain and global warming Wind power is… Renewable, but will only work high up and on windy days.

Generating electricity Over ground cables are… Expensive to build and produce radioactive waste but don’t release any pollutant gasses Underground cables are… Cheap but can be affected by weather Fossil fuels are… cheap, and renewable, but they require a lot of valuable land to grow crops on Nuclear fuels are… Expensive to install and will only work on sunny days, but is rebewable Biofuels are… Are more reliable, but faults cant be fixed easily Solar power is… Renewable, but requires a large power station to built on top of volcanic sites which can be an eyesore Geothermal power is… Readily available and can be transported easily, but cause pollution, acid rain and global warming Wind power is… Renewable, but will only work high up and on windy days.