Energy Resources Flashcards
What are fossil fuels?
Natural resources that form underground over millions of years
What is the main problem with renewable energy?
Don’t provide much energy and some are unreliable as they depend on weather
How does wind power work?
Each wind turbine has generator & rotating blades turn generator and produce electricity
What are the disadvantages of wind turbines? Name 4
- Turbines stop when wind stops/if wind is too strong = impossible to increase supply when there’s extra demand
- Spoil the view
- Very noisy
- Initial costs are quite high
What are the advantages of wind turbines? Name 3
- No fuel costs and minimal running costs
- No pollution (expect in manufacture)
- No permanent damage to landscape
How does solar power work?
Solar cells generate electric currents directly from sunlight
What is solar power mainly used for?
Used to generate electricity on a relatively small scale
What are the advantages of solar power? Name 3
- No pollution
- In sunny countries = very reliable source of energy
- Running costs almost nil
What are the disadvantages of solar power? Name 3
- Lots of energy and some pollution in manufacture
- Only reliable in daytime/sunny days
- Can’t increase power output when there’s extra demand
What is geothermal power?
Uses energy from underground thermal energy stores
What is geothermal power used for?
To generate electricity or to heat buildings directly
Where is geothermal power possible?
In volcanic areas where hot rocks lie near the surface
What does geothermal power use a source of energy?
Slow decay of various radioactive elements (uranium) deep inside Earth
What are the advantages of geothermal power? Name 2
- Brilliant free energy that’s reliable
2. Very few environmental problems
What are the disadvantages of geothermal power? Name 2
- Aren’t many suitable locations for power plants
2. Cost of building a power plant is high compared to amount energy it produces
What does hydro-electric power essentially do?
Transfers energy from kinetic store of falling water
How does hydro-electric power require?
Requires flooding of a valley by building a big dam
How does hydro-electric power work?
Rainwater is caught and allowed out through turbines
What are the advantages of hydro-electric power? Name 4
- Can provide immediate response to an increased demand for electricity
- No fuel costs or minimal running costs
- Reliable (expect in times of drought)
- Useful way to generate electricity on small scale in remote areas
What are the disadvantages of hydro-electric power? Name 4
- Big impact on environment due to flooding of valley
- Rotting vegetation releases methane and carbon dioxide
- Loss of habitat for some species
- Initial costs are high
- Reservoirs look unsightly when dried up
How can we reduce the impacts of hydro-electric power plants on humans?
Build them in remote valleys
How does wave power work?
Lots of little wave-powered turbines located around coast - moving turbines are connected to generator
What are the advantages of wave power? Name 3
- No pollution
- No fuel costs and minimal running costs
- Very useful on small islands (as it can provide energy on a small scale)
What are the disadvantages of wave power? Name 4
- Fairly unreliable since waves die when wind drops
- Disturbs seabed and habitats of marine animals
- Spoils view/hazards to boats
- Initial costs are high
- Never likely to provide energy on large scale
What are tidal barrages?
Big dams built across river estuaries with turbines in them
How do tidal barrages work?
As tide comes in, it fills up estuary - water is allowed out turbines at controlled speed
What are tides produced by?
Gravitational force of Sun and Moon
What are the advantages of tidal barrages? Name 4
- No pollution
- Pretty reliable, they happened twice a day without fail (and always near predicted height)
- No fuel costs and minimal running costs
- Has potential for generating a significant amount of energy
What are the disadvantages of tidal barrages? Name 3
- Initial costs are moderately high
- Height of tide is variable - lower (neap) tides = less energy than bigger (spring) tides
- Prevent free access by boats, spoils view and alters habitats
What are bio-fuels made from?
Plant products or animal dung
How can bio-fuels be used?
Can be burnt to produce electricity or run cars in same way as fossil fuels
What are the advantages of bio-fuels? Name 2
- Supposedly carbon neutral
2. Bio-fuels are fairly reliable
How can bio-fuels be carbon neutral?
If you keep growing plants at the rate that you’re burning things
Why are bio-fuels fairly reliable?
Crops take relatively short time to grow and different crops can be grown all year round
Crops needed for bio-fuels grow at different times of the year. How can we combat this?
Bio-fuels are continuously produced and stored still they’re needed
What are the disadvantages of bio-fuels? Name 4
- Cost to refine bio-fuels is very high
- There may not be enough space or water to meet demands for crops that are grown for food
- Species losing their natural habitats (large areas of forest are cleared up to grow bio-fuels)
- Decay and burning of vegetation increases carbon dioxide and methane emissions
What is the advantage of using fossil fuels? Name 3
- Reliable - power plants can respond quickly to changes in demand
- Running costs aren’t expensive
- Has fairly low fuel extraction costs
What are the environmental impacts of using fossil fuels?
- CO2 released = global warming
- Burning coal & oil = releases sulfur dioxide = acid rain (harms trees, soil)
- Views spoilt by fossil fuel power pants
- Oil spillages = serious environmental problems (e.g. affects mammals and birds at sea)
Which type of coal mining messes up landscape the most?
“open-cast mining”
How can we reduce acid rain from forming when fossil fuels are burnt?
- Taking sulfur out before fuel is burned
2. Cleaning up emissions
What is the advantage of using nuclear power? Name 2
- Clean
2. Nuclear fuel is relatively cheap
What is the disadvantage of using nuclear power? Name 3
- Risk of a major catastrophe
- Nuclear waste is dangerous & difficult to dispose of
- Overall cost of nuclear power is high due to cost of power plant & final decommissioning
How are fuels selected?
By looking at their ease of storage, energy content and safety
