Generating electricity

what is renewable energy?

a source of energy which is not going to run out

what is non-renewable energy?

a source of energy which is going to run out

what are the advantages of wind and solar?

renewable, no waste, no pollution

what are the disadvantages of wind and solar?

low power output, unreliable, considered unsightly

what are the advantages of coal, oil and gas?

reliable, large power output

what are the disadvantages of coal, oil and gas?

non-renewable, produces greenhouse gases, causes acid rain

what are the advantages of nuclear?

reliable, large power output, no greenhouse gases

what are the disadvantages of nuclear?

non-renewable, long start up time, produces radioactive waste, expensive to commission and decommission

what are the advantages of hydroelectric?

renewable, reliable, short start up time, no waste or pollution

what are the disadvantages of hydroelectric?

not many suitable places for this power station, must flood a large area which affects wildlife

what are the advantages of tidal power?

renewable, no waste or pollution

what are the disadvantages of tidal power?

must flood a large area which affects wildlife

what are the advantages of biomass?

renewable, reliable, carbon neutral

what are the disadvantages of biomass?

uses a lot of crops which require a lot of land to grow

what is the equation for efficiency?

%efficiency = energy usefully transferred / total energy supplied x 100%

where is heat created in a thermal power station?

in the furnace

how is heat created in the furnace of a thermal power station?

by burning a fuel, or a nuclear reaction in nuclear power

what does heat turn water into in a thermal power station?

steam

what is the national grid?

a network of cables which connects every power station to every home, shop, factory, school, hospital and other consumers

what does a step up transformer do?

increases the voltage, which reduces the current and lowers heat losses in the cables. This increases the gird’s efficiency

what does a step down transformer do?

lowers voltage to a safer level

what don all power stations need?

an energy resource

what are the advantages of the national grid?

can react to a change in demand, provides back up, reliable

how does the national grid maintain a reliable supply of electricity?

responds to a change in demand, maintains a supply even if a power station breaks down, it has backups / imports from abroad

what can a surge in demand cause?

a black-out