P1.4 Flashcards
Which power stations have the slowest start up time?
Nuclear
What happens to the energy in a furnace or nuclear reactor (chemical)
Water is heated in a boiler (heat) which turns to steam which drives a turbine (kinetic) and then a generator (electrical) to the national grid to homes
Non renewable (will run out, all do damage to environment) energy sources:
Fossil fuels: coal, oil and gas
Nuclear (uranium & plutonium)
What’s the problem with fossil fuels?
Release co2 which causes global warming
How can the amount of co2 released by fossil fuels being reduced?
Capture the co2 before it is relaxed into the atmosphere
Name the renewable (never run out, most do damage to environment, unreliable weather dependant) energy sources:
Biofuels Wind turbines Water - wave generator, hydroelectric/pumped storage system & tidal Solar Geothermal
How is energy generated from the wind?
Wind turbines contain generators which electricity is directly generated from the wind turning the blades which turn the generator
How is energy generated from waves?
A wave generator floats on the water and moves up and down which generates electricity - passes through a cable back to shore
How is energy generated from tide?
High tide is trapped behind a barrage it is released and falls to the lower levels driving a turbine
How is energy generated from hydroelectric?
Rainwater is collected in a reservoir and then pumped & flows through turbines as it flows down hill which drives a generator
How is energy generated from pumped storage system?
Spare night time electricity is used to pump water up to a higher reservoir which can be released quickly during periods of peak demand - storing energy which has already been generated
How is energy generated from the sun?
Solar cells absorb the Suns radiation and convert it to electrical energy
How is energy generated from geothermal?
In areas with volcanic activity (energy is released underground due the earths radioactive decay processes which heat the surrounding ricks), deep holes are drilled & cold water is pumped down under ground to the hot rocks and then returns to the surface as steam or hot water which can drive a turbine and generate electricity
How is energy generated from fossil fuels?
Burnt in power stations
How is energy generated from nuclear(uranium & plutonium) ?
Brunt in a nuclear power station involves fission of uranium/plutonium producing heat which drives a turbine
How is energy generated from biofuels?
Plant and animal waste is burnt in power stations - carbon neutral
What are the main problems with generating electricity?
Release of substances into the atmosphere
The production of waste products
Noise and visual pollution
Destruction of wildlife habitats
What is carbon capture and storage?
Prevents the build up of carbon dioxide in the atmosphere so we catch and store it in old oil and gas fields eg under the North Sea
What is the national grid?
A system/network of transformers and cables which transfer energy from power stations to consumers.
What do step transformers do?
Increase the voltage
What do step down transformers do?
Decrease the voltage
How do we transmit the huge amounts of power needed?
Higher voltage or current
What’s the problem with high current?
Lots of energy is lost through heat in the cables
What is it cheaper to do?
Boost the current up high and the current down low
How do we transmit electricity?
Through overhead or underground cables
What does the national grid have to do?
Meet our demand and our demand is increasing
What is a solar power tower?
Mirrors reflect the sunlight onto a water tank & heat the water which produces steam which turns a generator
What are solar heating panels?
Water flows through them and is heated but the sons energy
Which power stations have the fastest start up time?
Gas
