Flashcards in Energy Resources and Electrical Generation Deck (40):
What is a non-renewable energy resource?
A non-renewable energy resource is one that effectively cannot be replaced once it have been used
What are examples of fossil fuels?
coal, oil and natural gas
What are example of nuclear fuel?
uranium and plutonium
What happens when fuels are burnt?
1. Heat is released which boils the water, which produces high pressure steam
2. This high pressure steam, makes the blades of a turbine spin
3. The turbine then turns a generator which generates electricity
4. chemical or nuclear, heat, kinetic, electrical
What are the advantages of using fossil fuels?
1. Burning fossil fuels releases a lot of energy, relatively cheaply
2. Reliable energy resource: does not rely on weather
3. Already have fossil fuel power stations and so do not need to spend money on new technology
4. Can be started more quickly than nuclear power stations but still take hours to start producing electricity
coal, oil and gas (gas responds quickest to demand surges)
What are the disadvantages of using fossil fuels?
1. Releases carbon dioxide which contributes to climate change and global warming
2. Most types of coal and oil contain sulphur which when burnt is converted into sulphur dioxide which combines with water to form acid rain which can harm trees, soil and have a huge impact on wildlife
3. Non-renewable and the fuel could be used elsewhere e.g. pharmaceutical industry
What is nuclear fission?
1. Nuclear fission involves an atoms nucleus to be hit by a neutron causing it to split into smaller nuclei. Two or three neutrons are released which will then hit into other nuclei creating a chain reaction. When a neutron hits an atom's nucleus energy is released
2. Heat is produced to make steam turns a turbine etc.
3. Nuclear, heat, kinetic, electrical
What are the advantages of using nuclear fuel
1. Can occur 24/7
2. Does not rely on weather
3. No GHG released
4. Very efficient one pellet of uranium fuel is equal to one tonne of coal (so relatively cheap as cost of energy per unit fuel is low)
What are the disadvantages of using nuclear fuel?
1. Nuclear reactors are expensive to build and maintain
2. Cannot be turned on instantly so cannot meet sudden surge of demand
3. Running cost is low but pay-pack time is very long
4. Risk of nuclear accident and leaks of radioactive material
5. Left with radioactive waste
6. Very expensive to decommission when station is old or no longer efficient
What is a wind farm?
-Wind turbines placed in exposed places e.g. on moors, around the coast or out at sea
-Wind turns the blades (a turbine) which drives a generator which generates electricity
-Kinetic energy of moving air, electrical energy
What are the advantages of using a wind farm?
1. Renewable and tried and tested technology
2. No GHG released
3. Cheap to run as wind is free and turbines are tough and reliable
What are the disadvantages of using a wind farm?
1. Can cause environmental damage as they change the appearance of the landscape
2. Cause noise pollution and kill birds and bats
3. Dependent on weather
4. Expensive to set up
5. Can only occur in exposed areas
6. Cannot be relied upon to deal with a sudden surge of demand in energy
What is geothermal energy?
-Water is pumped to underground and the heat from sub-terrain rocks is used to boil the water, and the water is forced back up due to pressure to turn a turbine which drives a generator
-The source of much of the heat is the slow decay of various radioactive elements including uranium deep inside the Earth
-Heat, kinetic, electrical
What are the advantages of using geothermal energy?
1. Renewable and tried and tested technology
2. No great impact on environment
3. Long life span of 50+ years
What are the disadvantages of using geothermal energy?
1. High cost to drill down several km and high cost to set up power plant
2. Only possible in few places where hot rocks lie near the surface
3. Need high water supply
What is active solar energy?
-Light energy from sunlight is turned directly into electrical energy via solar (photovoltaic) cells
-They generate direct current
What are the advantages of using solar active energy?
1. Sun is renewable energy resource and tried and tested technology
2. Low maintenance cost as running cost is low
3. No GHG released
What are the disadvantages of using solar active energy?
1. Solar cells are initially expensive
2. Not very efficient; used to power small scale e.g. calculators and watches that do not use much energy. They are also used in remote places where there is not much choice (e.g. deserts) and in satellites
3. Dependent on weather, and does not work well at night (and in winter in some places) (but solar calls can be linked to reachable batteries to create a system that can store energy during the day for use at night)
4. Not practical of too expensive to connect to national grid, as cost of connecting them to the National Grid can be enormous compared with the value of electricity generated
What is passive solar power?
When sunlight (light energy) is transferred directly into thermal energy via solar panels
1. Water is pumped through copper pipes (good conductor of thermal energy)
2. Surface of sheet and pipes have a matt black finish, as then best absorber of heat radiation
3. Glass above the copper traps a layer of air to insulate the unit and retain heat, it allows heat and light from the sun in
4. Backing is also designed to stop heat escaping to the surroundings
These heat up the water (used widely to provide water heating)
What are the advantages of using passive solar power?
1. Reasonably efficient, more cost efficient that active solar power
2. Renewable and tried and tested technology
3. Free after set up
What are the disadvantages of using passive solar power?
1. Large set up cost
2. Large collecting area needed
3. Depends on weather; works best in sunny areas
4. JUST produces heat and not electricity
What is wave power?
1. Rising water columns pushes air past a turbine and falling water column sucks air back past the turbine (bobbing motion of waves) Kinetic energy of waves converted into electrical energy, the spinning turbine drives a generator etc.
2. On way of harvesting wave power is with lots of small wave converters located around the coast
-As waves come in the shore they provide an up and down motion which can be used to drive a generator and as the rising water pushes air past the turbine and the spinning turbine is sued to drive a generator
3. The kinetic energy of thew waves is converted into electrical
-An oscillating water column system for using wave energy
What are the advantages of using wave power?
1. Renewable as the movement energy of the waves is continuously avaliable
2. No GHG/ pollution
3. No fuel costs and minimal running cost
4. No unwanted waste products
What are the disadvantages of using wave power?
1. Unreliable as needs decent wind
2. Large collecting area needed
3. Spoils the view and a hazard to boats
4. Unlikely use on large scale but can be very useful on small islands
What is tidal power?
-Tidal barrages built across river estuaries with turbines
-The tide as it flows in and out, turns the turbines and drives a generator
-Some energy companies are now developing turbines that can just be underwater with no barrage
-Kinetic energy of water is turned into electrical energy (make this sentence better!)
What are the advantages of using tidal power?
1. Renewable as uses a small fraction of the continuous supply of gravitational energy
2. Tried and tested technology
3. No pollution/ GHG
4. No fuel cost and minimal running cost
What are the disadvantages of using tidal power?
1. Limited areas in the world suitable for building dams for tidal energy as you need a large tidal range
2. Disturbs wildlife habitat (estuary) ecology if barrages are used
3. Spoils the view and prevents free access by boats
4. Although tides are pretty reliable the height of tide is variable: lower tide means less energy than higher tides
5. Not available continuously but that tides at which it will are predictable
6. Initial costs are moderately high, but there are no fuel costs and minimal running costs
What is hydroelectric power?
1. Water is stored in high reservoirs built in mountains. 2. When the water flows down the GPE of the water is converted into kinetic energy
3. The water falls, turning a turbine which drives a generator transferring the kinetic energy into electrical energy
4. Hydroelectric power often requires the flooding of a valley by building a big dam and rainwater is caught and allowed out through turbines, converting the GPE of the water to kinetic energy as it falls, which is them converted to electrical energy by the generator
What are the advantages of using hydroelectric power?
1. Renewable as moving water is a renewable resource
2. No pollution/ GHG released
3. Can be started quickly in times of increased demand and reliable (except in a drought), as if more energy is needed than the National Grid can supply, the water is released
4. No fuel cost and low running cost
What are the disadvantages of using hydroelectric power?
1. Building reservoirs can spoil the landscape (location in remote valleys can avoid some of these problems)
2. Destroy or alter natural habitat for wildlife and flooding behind the dam can cause environmental problems as rotting vegetation releases methane and carbon dioxide)
3. Only feasible in mountain areas or on large rivers
4. High initial cost
What is a renewable energy resource?
A renewable energy resource is one that will not run out
What is predicted demand?
-Early morning (wake up and turn stuff on)
-Winter higher demand for heat than in summer
What is unpredicted demand?
-Popular TV soap, all the adverts, decide to make a cup of tea and electric kettles use up a lot of power
What are some of the costs needed to be considered when using a renewable energy resource?
1. Start up cost
2. Maintenance cost
3. Safety and precautions cost
4. Cost of fuel
6. Cost to decommission
7. Pay back time
What must electrical companies be able to do?
Companies that supply electricity must be able to cope with changes in demand or they are forced to cut off electricity to some consumers and that leads to bad customer relations and a reduction is the amount of electricity sold, thus lowering the companies income
Explain pumped storage
1. Most large power station have huge boilers that are kept running all night even though there is low demand
2. This means that there is a surplus of electricity at night and pumped storage is one of the best solutions at storing this spare energy for later use
3. In pumped storage 'spare' night time electricity is used to pump water up to a higher reservoir
4. This can then be released quickly during periods of peak demand such as at teatime each evening to supplement the steady delivery from the big power stations
5. Unlike hydroelectric power pumped storage isn't a way of generating instead it is a way of storing energy that has already been generated
Why are hydroelectric power a good way to respond to a sudden change in demand?
1. They can operate in reverse by using surplus electricity generated by other power stations that cannot be shut down quickly to pump water back up into the high level reservoirs
2. These then convert the electrical energy into GPE which can then be reconverted when needed at a later time
What are different types of energy resources?
3. Geothermal resources
4. Solar heating resources
5. Solar cells
6. Fossil fuels
7. Nuclear power
How do solar panels work?
1. Solar panels are more simple than solar cells
2. They are black water pipes inside a glass box
3. The glass lets heat and light from the Sun in which is then absorbed by the black pipes and heats up the water
4. Like Solar cells they cost money to set up but they are renewable and free after that
5. They are only used for small scale energy production