unit 6 Flashcards
by burning one kg of fossil fuel how much energy can be released
30 million joules of energy
what happened inside coal or gas or oil-fired up a power station
the burning fuel would heat up water that would produce steam, which drives turbines to move generating electricity
where do fossil fuels come from
they come from long-dead animals and planets
what is a biofuel
it is any fuel taken from a living or a recently living organism, it is renewable and carbon-neutral
where does the energy of nuclear fuel come from
it comes from the splitting of the unstable uranium atom
how is the energy transferred from nuclear fusion
it is transferred by the coolant pumped to the core, the coolant is very hot when it leaves the core, it leaves the pipe to a heat exchanger then back to the core. the energy transferred to the is used to turn water into steam in the heat exchanger, the steam would turn turbines that would end up generating electricity
compare a nuclear power station, with a fossil fuel power station
the fuel in the nuclear power station is either uranium or plutonium, the energy released in the nuclear power station is 10 000 more (300 000 MJ)) than the energy released in the fuel power station (30 MJ), the nuclear power station would produce nuclear waste, and the fuel power station would release greenhouse gases when it is burned and the nuclear power won’t because uranium is not burned
what is renewable energy
it is a natural source of energy that can never run out because they are always being replenished by natural sources
what are wind turbines, how does in generating electricity, and what is their disadvantages
wind turbines is an electricity generator on top of a long narrow tower, the wind drives the turbine’s blades this would turn a generator, the more wind there is the more energy is generated, and its disadvantages that are a very unreliable force. no wind = no energy generated
what are wave generators
they are floating generators that use waves to make them move and down making the generator turn on causing energy to be generated.
how is energy transferred in wave generators
a cable between the generator and the shortline delivers energy to the grid system
what are the disadvantages of wave generators
- they need to withstand storms
- the don’t produce a constant supply of electricity
- they require alot cables and building along the coast to connect wave generators to the electricity grid which can spoil areas of the coastline
- the can affect marine life and birds
how is hydroelectric power generated
it is generated when rainwater is collected in reservoirs flows downhill, this would drive turbines at the bottom of the hill generating electricity
how is tidal power generated
tidal power stations trap water from each high tide behind a barrage. the high tide can be released into the sea by turbines, the turbines would drive generators in the barrage producing energy
what are the disadvantages of using solar cells
- they are useful where only a small amount of electricity is required
- they are very expensive but coast nothing to run
- lots of them are needed and a lot of sunshine in order for them to generate enough useful power
what are solar cells
the are flat solid cells that use energy to heat water directly
what is a solar heating panel
it is a long tower that uses thousands of flat mirrors to reflect sunlight on a big water tank at the top of the tower as the mirror would be controlled by a computer so they can track the sun, where the water in the tank would be turned into steam by the heating effect from some radiation, as the steam would be pipped down to the ground level, where it would turn electricity generators.
where does geothermal energy come from
the energy release comes from radioactive substances deep within the earth
how does geothermal power stations work
geothermal power stations are built above volcanic area or where they are hot rock deep below the surface, where water would be pumped down to these rocks producing steam, then the steam of drive electricity turbines at ground level
what are the disadvantages of fossil fuels and how can they be avoided
- burning fossil fuels can lead to greenhouse gasses that would lead to global warming such as carbon dioxide, but this can be avoided by using carbon capture and storage (CCS), which would stop the emission of carbon dioxide in fossil fuel power station by capturing the carbon and storing it in old oil and gas fields
- burning fossil fuels can lead to the production of sulfur dioxide which causes acid rain, but this can be avoided by filtering out the sulfur impurities from the fuel before burning it
- fossil fuels aren’t renewable, to avoid this we should start relying more on nuclear power and on renewable resources
what are the advantages of nuclear power
- no greenhouse gasses (unlike fossil fuels)
2. much more energy is released from each kilogram of uranium (or plutonium) fuel than fossil fuel
what are the disadvantages of nuclear power
- in would produce radioactive waste that can be stored safely for centuries
- an explosion in the power station can lead to the release of radioactive material over a wide area that would affect the area and the people and animals living in it
what are the advantages of renewable power
- they will never run out
- they do not produce greenhouse gases or acid rain
- they do not create radioactive waste
- they can be used here connection to the national grid is uneconomic
what are the disadvantages of renewable power?
- they currently dont meet the world energy dumand\
- wind turbines cause a whining noise disturbing people nearby, and some people consider them unsightly
- the tidal barrage affect river estuaries and the habitats of creatures and the plants living there
- hydroelectricity requires a lot of reservoirs of water that can affect nearby plant or animal
- habitats are loaded to create dams
- solar cells need to cover a huge area in order to generate large amounts of energy
- renewable resources aren’t reliable
