Electricity Generation Flashcards
How is electricity generated?
Moving a magnet inside coil of wire
What is electromagnation?
When magnet is moved in & out of coil, current is generated
How can we induce more electric current?
Use stronger magnet
Use coil wire with mor turns on magnet
Move magnet faster
What is the first step for a power station to produce energy?
Fuel burned to produce heat in burner
Chemical energy in fossil fuels transferred to heat energy
What is the second step for a power station to produce energy?
Heat used to turn water into steam through boiler
Heat energy used to boil water, forming steam & kinetic energy
What is the third step for a power station to produce energy?
Steam drives turbine, which is connected to generator
Kinetic energy of steam transferred to kinetic energy of turbine which drives generator
What is the fourth step for a power station to produce energy?
Rotating generator makes electricity
Kinetic energy -> electrical energy
What is the energy flow diagram in a a power station?
Chemical energy & fossil fuels
/. -> heat & sound
Kinetic energy (or heat) in steam
/. -> heat & sound
Kinetic energy in turbine.
/. -> heat & sound
Electricity energy from generator
What parts do all transformers have?
Primary coil
Secondary coil
Iron core
What is a primary coil?
The input voltage is connected across this coil
What is a secondary coil?
The output voltage is across secondary coil
What is an iron core?
Links coils magnetically, no current flows in iron core
What are the 2 types of transformers?
Step-up & step-down
What is a step-up transformer?
Found after generator in power station, but before grid
What is a step-down transformer?
Before electricity comes into our homes
What does a step-up transformer do?
Increases voltage
Decreases current (to reduce heat loss)
Has more turns on the secondary coil than primary coil
Has thinner, cheaper wires
What does a step-down transformer do?
Decreases voltage
Increases current
Has more turns on primary coil than second coil
What is the definition of non-renewable energy? Examples?
An energy source that has a finite supply
Fossil fuels
Nuclear energy
Biomass
What is the definition of renewable energy? Examples?
Energy which is collected from resources that will never run out or that are naturally replenished during human lifetime Light Wind Rain Waves
What are fossil fuels?
Formed from remains of dead plants & animals subjected to high temperatures & pressures over millions of years in the earth’s crust, e.g. Coal, oil & gas
What is nuclear energy?
Based on unclear fission, it relies on uranium ore which will run out
What is biomass?
Uses energy from combustion of wood & is non-renewable if plants aren’t regrown
What are advantages & disadvantages of wind energy?
Method - blades of wind turbine rotate & drive a generator
Adv- cost effective once built, unlimited supplies of wind
Dis- only works when wind blows, noisy & unsightly
What are the advantages & disadvantages of wave energy?
Method - forces of waves drive turbine linked to generator
Adv - cost effective once built, unlimited supply of wave energy
Dis - expensive to install, relatively inefficient
What are the advantages & disadvantages of light/solar energy?
Method - Solar cells use sun’s energy to enervate electricity
Adv - cost effective once built, unlimited supply of light energy
Dis - expensive to install, can be unreliable due to weather
