Section 4-Energy Resources and Energy Transfer P2 Flashcards
What are examples of non-renewable energy resources?
Coal
Oil
Natural gas
Nuclear fuels (e.g. uranium and plutonium)
What are 3 general facts about non-renewable energy sources?
- they will all run out
- they all do damage to the environment
- they provide most of our energy
How do most power stations generate electricity?
- as the fossil fuel burns(in oxygen)the chemical energy store is transferred to the thermal energy store of the water by heating
- the water boils to form steam which turns a turbine, transferring energy mechanically to the kinetic energy store of the turbine
- the turbine then powers the generator which produces an electric current, the generator transfers the energy electrically away from the power station via the national grid
What’re the advantages of burning fossil fuels?
- burning fossil fuels realises a lot of energy relatively cheaply
- it doesn’t rely on the weather so it’s reliable
- have lots of fossil fuel power stations already so we don’t need to spend money on new technology to use them
What’re the disadvantages of burning fossil fuels?
- all three fossil fuels release carbon dioxide into the atmosphere when burned. This contributes to global warming
- coal and oil also release sulphur dioxide which causes acid rain
- they’re going to run out eventually
What’s the process that goes on in a nuclear reactor?
- nuclear fission produces heat to make the steam to drive turbines rather than burning
- energy is transferred from nuclear stores to thermal energy stores by heating, then mechanically to kinetic and finally electrically on the grid
What’re the disadvantages of nuclear fuels?
- nuclear reactors are expensive to build and maintain, they also take longer to start up than fossil fuel ones
- processing uranium before use it causes pollution
- disposing of radioactive waste
- commissioning and decommissioning is expensive
What’re the advantages of nuclear fuels?
- doesn’t produce any greenhouse gases
- still plenty of uranium left in the ground
How are wind turbines used to create electrical energy?
- Wind power involves putting lots of wind turbines up in exposed places(e.g. out at sea)
- wind turbines use the kinetic energy store of moving air to generate electricity(wind turns the blades which turn a generator inside)
What’re the advantages of wind farms but more specifically wind turbines for generating electricity?
- wind turbines are cheap to run
- they’re very tough and reliable and the wind is free
- wind power doesn’t produce any polluting waste and it’s renewable(won’t run out)
What’re the disadvantages of wind farms but more specifically wind turbines for generating electricity?
- spoil the view(visual pollution) also noisy(sound pollution)
- need about 1500 of then to replace one coal-fired power station and that’d cover a lot of ground
- sometimes the wind isn’t strong enough to generate any power, it’s also impossible to increase supply when there’s extra demand
- expensive to set up(especially out at sea)
How is geothermal power used to create electrical energy?
- only possible in certain places where hot rocks lie near the surface(source energy-the slow decay of various radioactive elements)[some places use geothermal energy to heat buildings directly]
- water is pumped down in pipes to the hot rocks and forced back up due to pressure to turn a turbine which drives a generator (energy is transferred from thermal energy stores to kinetic and is then used to generate electricity)
What’re the advantages of using geothermal power?
-it’s free renewable energy with no real environmental problems
What’re the disadvantages of using geothermal power?
- main drawback is cost of drilling down several km
- cost of building power point is often high compared to the amount of energy we get out of it
- there’s very few places where this seems to be an economic option
How are solar cells used to capture the sun’s energy?
-solar cells(photocells) generate a direct current(DC-the same as a battery)from the sun’s energy
What’re the advantages of using solar cells to capture the sun’s energy?
- the sun is a renewable energy source(won’t run out)
- running cost are almost free
- no pollution produced while using them
What’re the disadvantages of using solar cells to capture the sun’s energy?
- very expensive initially(start up costs) and some pollution is produced in their production
- generally used on a small scale and it’s often too expensive or too impractical to connect them to the national grid
- rely on enough sunlight(so at night and in the winter in some places there can be a problem)-but they can be linked to rechargeable batteries to create a system to store energy
What’re the best uses of solar cells for generating electricity?
- to power calculators and watches
- in remote places like deserts because they don’t have much choice
- in satellites
How do solar water heating panels work? And what are some advantages and disadvantages?
Solar water heating panels are more simple than solar cells, they’re basically black water pipes in a glass box. The glass lets energy from the sun in, which is absorbed by the black pipes and heats up the water.
- cost money to set up but are renewable and free after that
- only used for small scale production
What’re two solar heating systems?
- solar water heating panels
- cooking with solar power
How does cooking with solar panels work? And what are some advantages and disadvantages?
-get a curved mirror, then you can focus the sun’s light
-this focus light can heat up pans used for cooking
Advantage: provide a renewable energy resource for outdoor cooking
Disadvantage: slow, bulky and unreliable (need lots of strong sunlight to work)
How is wave power used to create energy?
- lots of small wave converters, as waves come to the shore they provide an up and down motion which can be used to drive a generator
- the energy is transferred from the kinetic energy store of the waves to the kinetic energy store of the turbine and used to generate electricity
What’re the advantages of using wave power to generate electricity?
- No pollution
- It’s renewable
- no fuel costs and minimal running costs
- good on small scale
What’re the disadvantages of using wave power to generate electricity?
- visual pollution(spoiling the view)
- hazard to boats
- fairly unreliable since waves die out when the wind drops
- initial costs are high
How are tidal barrages used to generate electricity?
- tail barrages are big dams built across river estuaries with turbines in them, as the tide comes in it fills up the estuary to a height of several metres, this water can then be allowed out through turbines at a controlled speed(driving the turbines on the way)
- energy transfer from kinetic in water to kinetic of the turbine generating electricity
What’re the advantages of using a tidal barrage to generate electricity?
- no pollution
- renewable
- tides are pretty reliable but the height of the tide is variable
- no fuel costs and running cost are minimal
What’re the disadvantages of using a tidal barrage to generate electricity?
- they can prevent free access to an area by boat
- spoiling the view
- altering the habitat of the wildlife
- initial costs are moderately high
How do hydroelectric dams generate electricity?
- requires flooding of a valley by building a dam, rainwater is caught and allowed through turbines
- energy is transferred from the gravitational potential of the water to kinetic as the water falls
What’re the advantages of hydroelectricity?
- renewable energy source
- no pollution
- immediate response to demand (reliable unless there’s a drought)
- no fuel costs and running costs are low
What’re the disadvantages of hydroelectricity?
- environmental impact due to the flooding of a valley (rotting vegetation releases methane and CO₂) and possible loss of habitat for some species
- initial costs are high
- visual pollution
What’s pumped storage?
- Most large power stations have huge boilers which have to be kept running all night(even though the demand is low), this means there’s a surplus of energy at night and pumped storage is a way of storing this energy
- the spare electricity is used to pump water up to a higher reservoir
- this higher reservoir store can then be realised quickly for peak times
