Energy Resources Flashcards
(14 cards)
General uses
What do we use energy for?
Transport, electricity generation and heating.
List the main energy resources available for use on Earth (ie renewable and non-renewable sources)
Non-renewables: fossil fuels (coal, oil and gas) and nuclear fuel.
Renewables: Bio-fuel, wind, hydroelectricity, geothermal, the tides, the Sun and water waves.
Define non-renewable energy source
These energy resources will eventually run out. We have limited supplies of them.
Define renewable energy source
These energy resources will not run out. It is being (or can be) replenished as it is used.
Why are some energy resources more reliable than others?
Non-renewable resources can be used at any time as long as there is a supply of it. Renewable sources typically rely on some sort of natural change
How can each renewable source be unreliable?
Solar power is dependent on how sunny it is, and does not work at night so cannot be relied upon if demand is high at certain times.
Hydroelectricity cannot work if reservoirs run dry.
Tidal cannot work all the time because it is dependent on the times of high and low tide.
Wind and waves will be too weak on very calm days.
Why does energy demand vary?
At certain times of the day more or less energy is required (travelling at rush hour for example) so higher or lower rates of energy generation are required.
How does a power station generate energy?
A fuel is used to heat water producing steam. The steam turns a turbine which drives a generator.
What are the advantages of using
non-renewable resources?
● They produce a lot of energy per kg of fuel (high energy density)
● Fuel sources are relatively cheap (Although Uranium enrichment for nuclear power stations
can be expensive)
● Nuclear power stations produce no greenhouse gases.
● Nuclear power stations transfer much more energy per kg of fuel than from fossil fuels.
What are the disadvantages of using
non-renewable resources?
● Burning fossil fuels (coal, oil and gas) releases greenhouse gases such as Carbon Dioxide (CO2) into the atmosphere.
● They also produce sulfur dioxide (SO2) which causes acid rain.
● Nuclear power stations produce radioactive waste that needs to be stored for centuries before it is safe.
● An explosion in a nuclear reactor could release radioactive material over a wide area.
What are the advantages of using renewable
energy resources?
● They will never run out.
● They do not produce greenhouse gases or acid rain.
● They do not create radioactive waste products.
● It is not necessary to always build a big station. Solar panels can be small and fitted to houses
and wind turbines can be placed where it is regularly windy.
What are the disadvantages of using
renewable energy resources?
● They are not currently able to meet world demands for energy.
● Wind turbines produce noise and some people consider them unsightly.
● Tidal barrages affect river estuaries and the habitats of creatures and plants there.
● Hydroelectric schemes need large reservoirs of water which can affect nearby plant and animal life. Habitats are often flooded to create dams.
● Solar cells need to cover large areas to generate large amounts of power.
● Some renewable energy resources are not available all the time or can be unreliable.
How is the variable demand for energy met?
● Nuclear and coal power stations provide a constant amount of energy.
● Gas power stations and pumped storage systems provide for daily variations in demand and extra demand in winter.
● Renewable resources are used when demand is high and conditions are suitable.
● Renewable resources can be used at times of low demand to store energy.
Why don’t we just move completely to using
renewables?
● Lack of infrastructure
● Cost to implement
● Unreliability
