P1.4 Methods we use to Generate Electricity Flashcards
What are examples of non-renewable energy resources? (4)
The 3 fossil fuels: coal, natural gas and Oil, and Nuclear fuels like uranium and plutonium
What are issues with non-renewable sources of energy?
They will run out one day, they all do damage to the environment due to their emissions or with their mining and storage, but they are currently our main source of energy
What are examples of renewable sources of energy? (7)
Wind, tides, solar, biofuel, waves, hydroelectric and geothermal
What are the benefits of renewable sources of energy?
They will never run out, and although they do damage to the environment, it’s not as bad as non-renewables
What are the drawbacks of renewable sources of energy?
They don’t provide much energy and some of them are unreliable as they depend on weather
How do power stations supply produce electrical energy from fossil fuels? (4 steps)
- The fossil fuel is burnt converting its stored chemical energy into heat energy
- The heat energy is used to boil water to produce steam
- The steam turns a turbine, converting heat energy into kinetic energy
- The turbine is connected to a generator, which transfers kinetic energy into electrical energy
How is electricity produced from nuclear sources of energy?
It’s the same as the fossil fuel power stations, but energy is released from nuclear fission - nuclear power stations take the longest to start up
How is electricity generated from wind?
Similar to the turbines connected to a generator in a fossil fuel generator - The blades from a windmill are turned by wind which turns a generator, converting kinetic energy into electrical energy
What are the advantages of using wind energy? (1)
It produces no atmospheric pollution - apart from a little when the windmills are manufactured
What are the disadvantages of using wind energy?
Visual pollution - they spoil the landscape (but they can be removed leaving the scenery unharmed), noise pollution - they are very loud, and they do not produce power when there is no wind
How many windmills do you need to replace one coal-fired power station?
1500
How do solar cells produce electricity?
They produce electricity directly from the sun’s radiation
What are the benefits of using solar cells to produce electricity? (3)
No atmospheric pollution (a part from some when being manufactured), a very reliable source of energy is sunny countries and they are very expensive to buy but free running costs means it is cost-effective
What are the drawbacks of using solar cells to generate electricity? (3)
Can only produce electricity in the daytime, can only be used to generate electricity on a small scale and connecting them to the national grid would be too expensive
What has to be done in order to generate electricity from hydroelectric power?
The flooding of a valley bay building a big dam - rainwater is caught and allowed out through turbines
What are the advantages of using hydroelectric power stations? (4)
There is no atmospheric pollution, they are an immediate response to an increased demand for electricity, reliable (unless there is a draught), and although it’s initial costs are high, there’s no fuel and minimal running costs so it’s cost effective
What are disadvantages of using hydroelectric power stations? (4)
There’s a big impact on environment due to flooding of a valley, which causes vegetation to rot releasing methane and CO2*, destroys habitats and the reservoir looks ugly when it dries up
What is the need for pumped storage?
To store energy which has been generated at times of low demand e.g. at night, but can be used at times when there is high demand of electricity e.g. when Mia Khalifa releases a new vid
How is excess power used in a hydroelectric power station?
A pumped storage pumps water from a lower reservoir to an upper reservoir
What are tidal barrages?
Big dams built across river estuaries, with turbines in them which are connected to generators
What source of energy is in tidal barrages?
The gravity of the sun and moon, as this is what causes tides
What are the advantages of using tidal barrages? (5)
It causes no atmospheric pollution, the tides are reliable, store energy for when there is a high demand of electricity, they have the potential to generate a lot of energy, and although they have high initial costs, they have low running costs and don’t need fuel so they are cost effective
What are the disadvantages of using tidal barrages? (5)
Prevent access for boats to pass, spoils the view, alters the habitats of wildlife, the tide size is unpredictable and they don’t work when the water level is the same on either side of the barrage
How do you generate electricity using waves?
Lots of small wave-powered turbines are located around the coast - as the waves come in to the shore, they provide an up and down motion which can be used to drive a generator
What are the advantages of using waves to generate electricity? (2)
No atmospheric pollution, and they have a high initial cost but they don’t require fuel and have minimal running costs
What are the disadvantages of using waves to generate electricity? (4)
Spoils the view, hazardous to boats, unreliable, and they can only provide electricity on a small scale
What is geothermal energy?
Using heat energy from hot underground rocks to generate electricity
Where can geothermal energy be used?
In volcanic areas where hot rocks lie near the surface
Where does the heat from the rocks come from (in geothermal energy)
From radioactive elements (e.g. uranium) deep inside the Earth
How is geothermal energy used to generate electricity?
Steam and hot water rises to the surface and are used to drive a turbine, which is connected to a generator
What are the benefits of geothermal energy? (2)
It’s free energy with no real environmental problems
What are the drawbacks of geothermal energy? (2)
There aren’t many suitable locations for power stations and the cost of building a power station is often high compared to the amount of energy we can get out of it