1 Petrol diesel and kerosene are
fossil fuels made from crude oil.
Fossil fuels are a non-renewable
energy source that will
evententually run out.
2 Biofuels are made from
plants. Plants are a renewable
resource because more can
3 Ethanol is a biofuel made from
sugar beet or sugar cane. It can
be mixed with petrol so less petrol
4 If fuel crops are grown
instead of food this could put
up food prices.
5 When fuel crops grow
they take in carbon dioxide
that will be released when
6 Hydrogen makes a good fuel because...
6.1 ....it releases a large amount of energy.
6.2 ....it produces only water as a waste product
6.3 ...it can be made from water which is cheap and plentiful.
7 A problem with using
hydrogen for cars is that its
flammable and explosive.
8 When oxygen and hydrogen react together in
a fuel cell, the energy released is captured as
an electricity. This can be used to power a
9 The technology for using
hydrogen for a fuel is not
completely ready yet.
10 A good fuel will...
10.1 ...be easy to ignite and keep alight.
10.2 ...not produce much ash, smoke or polluting gases.
10.3 ...release a lot of energy per kg.
10.4 ...be easy to store and transport.
10.5 ...be cheap to produce and use.
11 Generating hydrogen by
electrolysis of water requires
electricity, which is mainly
produced by burning fossil
fuels. This means that using
a hydrogen fuelled car will
result in burning fossil fuels.