Day 2
You should spend about 20 minutes on
Questions 14-26,
which are based on Reading
Passage 2 below.
Out of Africa: solar energy from the Sahara
Vivienne Walt reports on how the Sahara Desert could offer a truly green solution to
Europe’s energy problems
A
For years, the Sahara has been regarded by many Europeans as a terra incognita1
of little economic value or importance. But this idea may soon change completely.
Politicians and scientists on both sides of the Mediterranean are beginning to focus
on the Sahara’s potential to provide power for Europe in the future. They believe
the desert’s true value comes from the fact that it is dry and empty. Some areas of
the Sahara reach 45 degrees centigrade on many afternoons. It is, in other words, a
gigantic natural storehouse of solar energy.
В
A few years ago, scientists began to calculate just how much energy the Sahara
holds. They were astonished at the answer. In theory, a 90,600 square kilometre
chunk of the Sahara - smaller than Portugal and a little over 1%
of its total area -
could yield the same amount of electricity as all the world’s power plants combined.
A smaller square of 15,500 square kilometres - about the size of Connecticut - could
provide electricity for Europe’s 500 million people. I admit I was sceptical until I did
the calculations myself, says Michael Pawlyn, director of Exploration Architecture,
one of three British environmental companies comprising the Sahara Forest Project,
which is testing solar plants in Oman and the United Arab Emirates. Pawlyn calls the
Sahara’s potential staggering’.
С
At the moment, no one is proposing the creation of a solar power station the size of
a small country. But a relatively well-developed technology exists, which proponents
say could turn the Sahara’s heat and sunlight into a major source of electricity -
Concentrating Solar Power (CSP).
Unlike solar panels, which convert sunlight directly
into electricity, CSP utilises mirrors which focus light on water pipes or boilers to
produce very hot steam to operate the turbines of generators. Small CSP plants
have produced power in California’s Mojave Desert since the 1980s. The Sahara
Forest Project proposes building CSP plants in areas below sea level (the Sahara
has several such depressions) so that sea water can flow into them. This water would
then be purified and used for powering turbines and washing dust off the mirrors.
Waste water would then supply irrigation to areas around the stations,
creating lush
oases - hence the ‘forest’ in the group’s name.
1
adapted from Time Magazine
*terra incognita - Latin, meaning an unknown land’
Reading Passage 2
D
But producing significant quantities of electricity means building huge arrays of
mirrors and pipes across hundreds of miles of remote desert, which is expensive.
Gerry Wolff, an engineer who heads DESERTEC, an international consortium of
solar power scientists, says they have estimated it will cost about $59 billion to begin
transmitting power from the Sahara by 2020.
E
Building plants is just part of the challenge. One of the drawbacks to
CSP technology
is that it works at maximum efficiency only in sunny, hot climates - and deserts tend
to be distant from population centres. To supply Europe with 20% of its electricity
needs, more than 19,300 kilometres of cables would need to be laid under the
Mediterranean, says Gunnar Asplund, head of HVDC research at ABB Power
Technologies in Ludvika, Sweden. Indeed, to
use renewable sources of power,
including solar, wind and tidal, Europe will need to build completely new electrical
grids. That’s because existing infrastructures, built largely for the coal-fired plants
that supply 80% of Europe’s power, would not be suitable for carrying the amount of
electricity generated by the Sahara. Germany’s government-run Aerospace Centre,
which researches energy, estimates that replacing those lines could raise the cost
of building solar plants in the Sahara and sending significant amounts
of power to
Europe to about $465 billion over the next 40 years. Generous government subsidies
will be needed. ‘Of course it costs a lot of money,’ says Asplund. ‘It’s a lot cheaper to
burn coal than to make solar power in the Sahara.’
F
Meanwhile, some companies are getting started. Seville engineering company
Abengoa is building one solar thermal plant in Algeria and another in Morocco, while
a third is being built in Egypt by a Spanish-Japanese joint venture. The next step will
be to get cables in place. Although the European Parliament has passed a law that
aids investors who help the continent reach its goal of getting 20%
of its power from
renewable energy by 2020, it could take years to create the necessary infrastructure.
G
Nicholas Dunlop, secretary-general of the London-based NGO e-Parliament,
thinks companies should begin transmitting small amounts of solar power as soon
as the North African plants begin operating, by linking a few cable lines under the
Med. ‘I call it the Lego method,’ he says. ‘Build it piece by piece.’ If it can be shown
that power from the Sahara can be produced profitably, he says,
companies and
governments will soon jump in. If they do, perhaps airplane passengers flying across
the Sahara will one day count the mirrors and patches of green instead of staring at
sand.
Which paragraph contains the following information?
Write the correct letter, A -G , in boxes 14-18 on your answer sheet.
NB You may use any letter more than once.
14
a mention of systems which could not be used
15
estimates of the quantity of power the Sahara could produce
16
a suggestion for how to convince organisations about the Sahara’s potential
17
a short description of the Sahara at present
18
a comparison of the costs of two different energy sources
Questions 19-22
Look at the following statements (Questions 19-22) and the list of organisations below.
Match each statement with the correct organisation, A-G .
Write the correct letter, A -G , in boxes 19-22 on your answer sheet.
19
They have set a time for achieving an objective.
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