Fossil
fuels like coal, oil and petrol are non-renewable;
when they’re gone, they’re gone. They
take millions of years to form and just minutes to
burn away!
We use vast amounts of energy in our everyday lives. We use electricity in our homes, work and schools; we use cars, trains and planes to travel.
Non-renewable
energy sources cannot be replaced in our
lifetime, or that of our children or even
our childrens’ children. Once these
energy sources have been used up that’s
it, they are gone forever. There is a real
danger we could run out of these supplies
before alternative energy sources are available.
At the present rate of use, the known coal supplies will last about 300 years and oil may not last for more than about 50 years.
A great deal of fossil fuel is burnt in power stations. The coal is burnt to boil water which in turn produces steam. The steam drives the fans of a large turbine (a very big dynamo) which then generates electricity. The electric current is transported to our houses by large power cables. The whole process is an example of how energy is transformed from chemical energy to heat energy to kinetic energy and then finally to electrical energy.
Some environmental problems with fossil fuels:
Oil Spills
Oil has to be transported from oil fields to where it is needed. Oil tankers, which can carry many tens of thousands of tonnes of oil, are regularly used to transport the oil. Unfortunately, accidents can and do happen and the oil spills that result from these accidents have caused some major environmental headaches. Local birds, fish and animals such as sea otters and seals are very vulnerable to oil spills. Although the immediate damage can often seem horrific, with the help of careful human clean-up operations and with natural processes that help clean the environment, the marine ecosystem can usually recover well.
Acid Rain
When coal burns, it produces gases like carbon dioxide, which are then released into the atmosphere. Other harmful gases produced by coal burning are sulphur dioxide and some nitrogen oxides. These dissolve in the water in the atmosphere to create weak solutions of sulphuric acid and nitric acid, which can then return to Earth as 'acid rain'. Unfortunately many trees and plants cannot thrive when the water they need is acidic like this and large areas of forest can be affected. In the worst cases the vegetation may be killed.
![[What swears at seagulls? - Crude oil.]](../../images/joke_seagulls.gif)
![[...did you know? - Trains used to be powered by coal.]](../../images/did-you-know-wings1.gif)
