Download ENERGY SOURCES 1. Some words are often used together. Such

ENERGY SOURCES
1. Some words are often used together. Such word combinations are called
collocations. Here are some words that make a collocation with “energy”:
to release (energy)
to store (energy)
to convert (energy)
to harness (energy)
to utilize (energy)
to capture (energy)
Read the sentences with these verbs and then match the verbs with their
definitions.
Oil was released into the sea.
Standard letters can be stored on floppy discs.
They converted the spare bedroom into an office.
We can harness the power of the wind to generate electricity.
We must decide how best to utilize what resources we have.
After two hours the hunters finally captured the tiger.
1) Capture
2) Convert
3) Harness
4) Release
5) Store
6) Utilize
a) to let a substance flow out
b) keep something until you need it
c) to control and use the natural force or power of something
d) to use something for a particular purpose
e) to change something into a different form or thing
f) to catch or take control of something by force or skill
2. Now underline all collocations with energy in the following text.
DIFFERENT SOURCES OF ENERGY
Apart from tidal energy and nuclear energy the Sun is the ultimate source of most of the
different forms of energy on Earth.
Fossil fuels
These are coal, oil, and natural gas and are essentially non-renewable energy sources.
They contain mainly carbon and hydrogen atoms and the energy is released when they
are oxidized to carbon dioxide and water.
Nuclear energy
In nuclear fission large atomic nuclei are split into smaller nuclei. In the process matter
is converted into energy. This process has been harnessed in nuclear power stations
and the energy released converted into electricity. Nuclear fission is capable of
producing large amounts of energy. The disadvantages include controlling the reactions
and all the problems associated with radioactive materials.
Nuclear fusion is potentially an even more powerful source of energy. It involves the
combination of small nuclei to make larger nuclei and is the source of the Sun's energy.
It has been used destructively in hydrogen bombs but the problems associated with
harnessing the energy in a controlled way have not been overcome and as yet it is of no
commercial use.
Other energy sources
These are generally renewable sources which are as yet not harnessed very efficiently.
They include wind power, wave power, and hydroelectric power, which use wind and/or
water to drive a generator. Tidal energy harnesses the gravitational force between the
Earth and the Moon but can only be generated when there is tidal movement.
Geothermal energy utilizes the heat stored in the interior of the Earth, which is
generated by gravitational forces and through natural radioactivity.
Biomass
Fuel produced by biological processes. The energy from the Sun is harnessed through
photosynthesis. When plant materials (e.g. wood) are burned the reverse process takes
place, releasing the energy.
The fermentation of starch and sugars from plant material can form ethanol; an
alternative fuel.
Biomass is a renewable source but cannot produce nearly enough energy to sustain the
energy demands of modern society.
Solar energy
Solar energy is non-polluting and freely available during daylight hours. It can be
harnessed by solar heating panels, which capture and store the energy directly, or
through photovoltaic cells, which convert the solar energy into electricity.
3. Which energy source do the following characteristics mentioned in the text refer to?
Next to each characteristic write FOSSIL FUELS, NUCLEAR ENERGY, BIOMASS,
SOLAR ENERGY or TIDAL ENERGY.
 is not able to satisfy current energy needs – 1) ______________
 has been used for violent purposes – 2) ______________
 is finite and cannot be produced at any time 3) ______________
 can be captured only at particular times 4) ____________ and 5) ____________
 releases the energy earlier captured from the sun – 6) ______________
 energy is released as particles are divided into smaller units 7) ______________
4. Scan the text (read it very quickly to find the information) and complete the table with
notes about how different sources pollute the environment.
Wind
Hydroelectric power
Nuclear fuels
Fossil fuels
There are many different forms of pollution. Wind power may cause little, if any,
chemical pollution but windmills can be noisy and unsightly. Similarly the building of
dams to provide hydroelectric power can destroy large areas of land and alter the local
ecology. Many energy sources also cause thermal pollution by heating the surrounding
water which lowers the dissolved oxygen content.
The most polluting fuels are fossil fuels and nuclear fuels. Radioactive materials
can escape from nuclear power stations into the air and water and spent radioactive
waste can remain radioactive for thousands of years. Coal and oil both contain sulfur,
which was once present in the amino acids of the plants and animals from which they
are made. This burns to form sulfur dioxide which is converted into sulfur trioxide and
then sulfuric acid -a constituent of acid rain.
At the high temperatures produced when fossil fuels burn oxides of nitrogen can
also be formed. These can react to form nitrogen dioxide, N0 2. This is converted into
nitric acid, which is also a constituent of acid rain. Nitrogen oxides contribute to
photochemical smog. They break down in the presence of sunlight to form oxygen
radicals and then secondary pollutants, such as ozone and peroxyacylnitrates (PANs).
Coal and oil also form particulates in the form of fly ash and soot from coal and carbon
particles from the incomplete combustion of gasoline (petrol) and diesel. Incomplete
combustion also produces carbon monoxide and petroleum fuels evaporate to produce
potentially carcinogenic volatile hydrocarbons. Natural gas is much cleaner but like all
fossil fuels increases the concentration of carbon dioxide in the atmosphere when it is
combusted. Carbon dioxide is a greenhouse gas and contributes to global warming.
5. According to this text, how would you define the meaning of the word “pollution”?
6. For an energy source to be useful it should have the following characteristics:
 it should be easiIy accessible
 it should release energy at a reasonable rate (not too slow or too fast)
 it should be cheap and plentiful
 if possible its use should not be detrimental to the environment or health.
Compare the usefulness of any two energy sources using the information from this
worksheet.