How are fossil fuels used to generate electricity ?
- fuel burned to heat a boiler full of water
- produces steam
[] also produces impurities in smoke when burned which is harmful to the environment - steam turns a turbine which in turn turns an electricity generator
How are biofuels like methane from anaerobic digestion of animal/plant waste, or the plants/waste directly used to generate electricity ?
- fuel burned to heat a boiler full of water
- produces steam
- steam turns a turbine which in turn turns an electricity generator
NET ZERO CARBON EMISSIONS, AS ORGANISM TAKES IN CARBON AND THAT SAME AMOUNT OF CARBON IS RELEASED WHEN THE FUEL IS BURNT
[] renewable
How are nuclear fuels like uranium and plutonium used to generate electricity ?
- nuclei of these elements are unstable and can be split in two
- when this happens, energy is released to the surroundings as heat
- a coolant passing the reactor takes in the thermal energy and then passes it to a heat exchanger through a pipe before flowing back to the reactor core
- this collected energy is then used to heat water into steam and turn turbines that turn electricity generators
How is wind energy used to generate electricity ?
- wind’s force turns a wind turbine
- the turbine then turns an electricity generator
How is wave power used to generate electricity ?
- generator floats on the surface of the water
- kinetic energy of waves rocks the generator
[] kinetic energy + rocking motion turns the electricity generator inside the device - cable between the device and the shoreline delivers the electricity to the grid system
How is hydroelectric power generated ?
- water collected in a reservoir allowed to flow down a hill
- turns turbines that turn electricity generators at the bottom
[] kinetic energy converted into electrical energy
How are tides used to generate electricity ?
- tidal power station traps water from high tides behind a barrage, then released into the sea again through turbines
- these turbines turn an electricity generator
- sometimes in coastal areas, undercurrents of tides pass through turbines on the sea bed, which turn a generator
- underwater cables used to transfer this electricity to the national grid
Describe the advantages and disadvantages of using fossil fuels for electricity
disadvantages
- non-renewable
- release carbon dioxide and greenhouse gases into the atmosphere, worsening the greenhouse effect
- release sulphur and nitrate gases which then react to become sulphur dioxide and nitrogen oxide, then react with condensed water vapour in clouds to form acid rain
[] these impurities can be removed from the fuel before burning it to prevent this
advantages
- reliable energy source
- provide a lot of energy
- carbon emissions could be circumvented by wider implementation of CCS (carbon capture storage)
[] captures and condenses carbon dioxide from air, then pumps it deep underground under sea
- short start-up time so can fulfil changing energy demands throughout the day easily
Describe the advantages and disadvantages of using nuclear fuels for electricity
advantages
- no release of greenhouse gases
- much more energy transferred per kg of fuel than fossil fuels, so is overall more energy efficient
disadvantages
- long start-up time
- fuel is non-renewable
- produces radioactive waste that remains dangerous for many years that has to be stored safely deep underground
- risk of nuclear accidents like Chernobyl if stations not handled properly
Describe the advantages and disadvantages of using biofuels for electricity
advantages
- carbon-neutral
- renewable
- relatively reliable
disadvantages
- if using plants as biofuel, could be used to feed people instead of being burnt
Describe the advantages and disadvantages of using wind turbines for electricity
advantages
- renewable
- no greenhouse gases or radioactive waste produced
- create jobs
disadvantages
- create humming noise that can upset residents nearby
- eyesores
- unreliable; it is not always windy and so electricity is not always generated by them
Describe the advantages and disadvantages of using wave power for electricity
disadvantages
- need lots of maintenance or replacement, as they must survive many storms and corrosion from the (salt)water
- eyesores along the coast
- no constant supply of electricity; unreliable
- may change tidal patterns due to breaking waves earlier, affecting marine (bird) life in the area
advantages
- renewable
- no harmful by-products
Describe the advantages and disadvantages of using hydroelectric power for electricity
advantages
- high electricity yield
- short start-up time
- renewable
- reliable
disadvantages
- take up lots of land to function
- may disrupt the surrounding environment
- habitats often flooded to create dams
- easily affected by droughts if water reservoirs dry up
Describe the advantages and disadvantages of using tidal power for electricity
advantages
- high energy output
- renewable
disadvantages
- unreliable
- disrupts tidal patterns, disrupting migration patterns etc. of marine birds
- underwater turbines can harm aquatic animals like fish
- barrages = eyesores
How are solar panels used to generate electricity ?
- solar CELL panel
[] absorb energy from sunlight and convert it to electrical energy
[] this can be stored in a battery or used directly - solar HEATING panel
[] absorb energy from sunlight and use it to directly heat water which can then be used in the household - in solar power towers, large mirrors (controlled by a computer to track the sun throughout the day) reflect sunlight back at a big water tank at the top of the tower
[] water turned to steam
[] steam piped down to ground level to turn turbines which then turn an electricity generator
How is geothermal energy used to generate electricity ?
- energy transferred by radioactive substances deep in the crust heat the surrounding rock
- water is pumped down to these rocks by the geothermal power station above
[] creates steam - steam drives turbines to generate electricity at ground-level
- can also be put through pipes to heat water or can be used as floor-heating
Describe the advantages and disadvantages of using solar power for electricity
disadvantages
- usually only useful where small quantities of electricity are needed, eg. in a calculator
- need many panels to be useful
- panels are EXPENSIVE to buy and install, and a battery to store the energy produced is also expensive
- unreliable source of energy, as the sun is not always intense or out at all
advantages
- work very well in hot, dry climates
- cost nothing to run, and so pay themselves back in energy savings
- are useful in remote areas where using the National Grid would be uneconomical
- don’t take up much space
- do not cause any noise
- reduces pressure on the national grid for energy supply for domestic purposes
How are the varying energy demands of the UK met throughout the day ?
- supplies with long start-up times like nuclear power stations, as well as coal-fired power stations kept on constantly to meet base demands
- gas-fired power stations + pumped storage schemes to meet additional demands and variances in winter and throughout the day
- when demand especially high and conditions right, renewable energy used
Compare the costs of running nuclear power, fossil fuel and renewable energy power stations
- nuclear
[] expensive to build, fuel and decommission once out of use - fossil fuels
[] cheap to install
[] costs for CCS in future likely to be expensive - renewable energy
[] largely expensive to install but cost (almost) nothing to run, so make up for it long-term
