08. P3 Generating Electricity Flashcards
Define - Acid rain
Environmental problem caused by sulfur dioxide (which is released by burning fossil fuels)
Define - Base load
Constant amount of power generated by power stations. Usually supplied by stations with large start-up times (coal, nuclear etc.) andother methods used tomeet the variations in demand.
Define - Biofuel
A carbon-neutral, renewable type of fuel obtained from living or recently living organisms (wood is common example)
Define - Carbon Capture and Storage
Stops the release of carbon dioxide from fossil fuel power stations. Known as CCS.
Define - Carbon-neutral
Only releases the same amount of carbon dioxide that it absorbed during its lifetime, so there is no overall increase in carbon dioxide by burning it.
Define - Fossil Fuels
Coal, oil and gas. Finite fuels which have been produced over millions of years.
Define - Geothermal energy
Uses heat from the energy released by radioactive substances deep within the Earth.
Define - Hydroelectric power
Uses a dam that directs water through a turbine to generate electricity.
Define - National grid
Network of cables and transformers that transfers electricity around the country.
Define - Nuclear fission
Splitting nuclei to release energy. Used in Nuclear power stations.
Define - Solar cell
Panel that converts energy from the sun into electrical energy. Also called a photovoltaic cell.
Define - Solar heating panel
Panel that converts energy from the sun to thermal energy by heating water which is passing through the pipes.
Define - Solar power tower
Uses many mirrors to reflect sunlight onto a water tank on top of a tower, steam produced turns turbines andthen generators.
Define - Start-up time
Time taken for power stations to start up. Nuclear has the longest, then coal, then oil, then natural gas. Hydroelectric has shortest start up time
Define - Step down transformer
Device for making the voltage of an AC supply lower.
Define - Step up transformer
Device for making the voltage of an AC supply higher.
Define - Tidal power
Uses trapped high tides to force water through a turbine to generate electricity.
Define - Turbine
Rotates when steam or water is pushed through it. Used to drive a generator.
Define - Wave power
Uses the movment of water waves to generate electricity by turning turbines and generators.
Define - Wind power
Uses the wind to turn turbines/generator, and generate electricity.
Advantages of biofuels
Renewable, Carbon neutral, reliable
Advantages of Geothermal energy
Free fuel costs, No carbon dioxide released, renewable, reliable
Advantages of hydroelectric power
No pollution, short start up time, fuel is free, reliable
Advantages of nuclear power
Uranium is highly available(for now) and reliable, Lots of energy released per kg of fuel, No greenhouse gases
Advantages of overhead cables
Cheaper to install and repair, easy to access so quicker, natural cooling by air, Thinner cables used
Advantages of tidal barrages
No pollution, Reliable, Free fuel costs
Advantages of underground cables
Not affected by bad weather, hidden, doesn’t harm low flying aircraft, reduced risk of shock
Advantages of wave power
No carbon dioxide or carbon particulates emitted, renewable source, no fuel costs
Advantages of wind power
No carbon dioxide or carbon particulate emitted, renewable source, no fuel costs
Disadvantages of biofuels
Large areas of land needed to grow fuel, large amounts of fuel needed to match a fossil fuel output.
Disadvantages of geothermal energy
Only possible in volcanic areas sos uitable sites difficult to find, expensive to build
Disadvantages of hydroelectric power
Flood a valley, loss of habitat, high build costs
Disadvantages of nuclear power
Produces nuclear waste, expensive to build, high safety costs, non-renewable
Disadvantages of underground cables
Expensive to install and fix, takes longer to install, Insulation needed to reduce risk of electrocution
Disadvantages of overhead cables
Eye-sore, Damages landscapes, Can be damamged by weather, Easy access allows possible vandalism, Hazard to low flying air crafts
Disadvantages of solar cells
Only works at day time, unreliable, high initial costs (although these are getting cheaper)
Disadvantages of tidal barrages
Prevents boat access, can affect habitat, high cost to build
Disadvantages of wave power
Spoils view , hazard to boats, unreliable (no wind = no waves)
Disadvantages of wind power
Spoils view(visual pollution), noise pollution, unreliable, large number needed (600ish) to produce same energy as a standard coal power station
Decribe the processes in a fossil fuel power station
Fuel is burnt to release heat energy and boils the water, Water turns to steam, steam turns turbines, which turns generator to generate electrical energy
Define - Finite
Will run out
How is nuclear power made safe?
Reactors are cooled by water, fission slowed down by control rods, Fission reaction encased in steel vessels and thick concrete.
Non-renewable
Resource that will run out once they’re used as they cannot be used again eg coal and oil
Renewable
A resource that can be replaced/regenerated and will never run out eg solar and wind
The national grid
The network of transformers cables and pylons that carry energy across the country
Advantages of solar cells?
Free fuel costs, No carbon dioxide released, renewable
What are tidal barrages?
Dams built across river estuaries which control the flow of tidal water
What does nuclear power stations use as fuel?
Uranium (and some plutonium)
Briefly describe nuclear fission in power stations
Nuclei splits into two smaller nuclei, releasing neutrons, and energy
Which non-renewable resource has the quickest start up time?
Natural gas
Why is the voltage stepped down?
The voltage is stepped down before it reaches the homes because it is less dangerous to use in homes
Why is the voltage stepped up?
Higher voltage = lower current through wires = less heat loss in wires
