2.1 Evaluate different methods of generating electricity given data including start-up times, costs of
electricity generation and the total cost of generating electricity when factors such as building and
decommissioning are taken into account. The reliability of different methods should also be
understood.evaluate ways of matching supply with demand, either by increasing supply or
2.1.1 Candidates should be aware of the fact that, of the fossil fuel power stations, gas-fired have the
shortest start-up time. They should also be aware of the advantages of pumped storage systems in
order to meet peak demand, and as a means of storing energy for later use. Compare the advantages
and disadvantages of overhead power lines and underground cables
2.2 Generating Electricity
2.2.1 In some power stations an energy
source is used to heat water. The
steam produced drives a turbine
that is coupled to an electrical
22.214.171.124 Energy sources include: the fossil fuels (coal, oil
and gas) which are burned to heat water or air;
Uranium and plutonium, when energy from
nuclear fission is used to heat water; Biofuels
that can be burned to heat water.
126.96.36.199.1 Water and wind can be used to drive turbines directly
188.8.131.52 Energy sources
used in this way
include, but are not
limited to, wind,
waves, tides and
the falling of water
184.108.40.206.1 Electricity can be produced directly from the Sun's radiation.
2.2.2 solar cells can be
used to generate
should be able to
220.127.116.11.1 1. Solar energy can only be harnessed when it is daytime and sunny.
18.104.22.168.1.1 2. Solar collectors, panels and cells are relatively expensive to manufacture although prices are
22.214.171.124.1.1.1 3. Solar power stations can be built but they do not match the power output of similar sized
conventional power stations. They are also very expensive.
126.96.36.199.188.8.131.52 4. In countries such as the UK, the unreliable climate means that solar energy is also unreliable as a
source of energy. Cloudy skies reduce its effectiveness.
184.108.40.206.220.127.116.11.1 5. Large areas of land are required to capture the suns energy. Collectors are usually arranged
together especially when electricity is to be produced and used in the same location.
18.104.22.168.22.214.171.124.1.1 6. Solar power is used to charge batteries so that solar powered devices can be used at night.
However, the batteries are large and heavy and need storage space. They also need replacing from
time to time.
126.96.36.199.1 1. Solar energy is free although there is a cost in the building of ‘collectors’ and other equipment
required to convert solar energy into electricity or hot water.
188.8.131.52.1.1 2. Solar energy does not cause pollution. However, solar collectors and other associated equipment /
machines are manufactured in factories that in turn cause some pollution.
184.108.40.206.1.1.1 3. Solar energy can be used in remote areas where it is too expensive to extend the electricity power
220.127.116.11.18.104.22.168 4. Many everyday items such as calculators and other low power consuming devices can be powered
by solar energy effectively.
22.214.171.124.126.96.36.199.1 5. It is estimated that the worlds oil reserves will last for 30 to 40 years. On the other hand, solar
energy is infinite (forever).