Renewable Energy
An insight into the progress in renewable energy research
A
The race is on for theultimate goal of renewable energy: electricity production at prices that arecompetitive with coal-fired power stations, but without coal’s pollution.Some new technologies are aiming to be the first to push coal from its positionas Australia’s chief source of electricity.
B
At the moment thefront-runner in renewable energy is wind technology. According to Peter Berginof Australian Hydro, one of Australia’s leading wind energy companies, there have been nodramatic changes in windmill design for many years, but the cumulative effectsof numerous small improvements have had a major impact on cost. 4 We’re reaping thebenefits of 30 years of research in Europe, without having to make the samemistakes that they did,』Mr. Bergin says.
C
Electricity can beproduced from coal at around 4 cents per kilowatt-hour, but only if theenvironmental costs are ignored. 『Australia has the second cheapest electricity inthe world, and this makes it difficult for renewable to compete,’says RichardHunter of the Australian Ecogeneration Association (AEA). Nevertheless, the AEAreports: The production cost of a kilowatt-hour of wind power is one fifth ofwhat it was 20 years ago,』or around 7 cents per kilowatt-hour.
D
Australian Hydro hasdozens of wind monitoring stations across Australia as pari of its aim tobecome Australia’s pre-eminent renewable energy company. Despite allthese developments, wind power remains one of the few forms of alternativeenergy where Australia is nowhere near the global cutting edge, mostly justreplicating European designs.
E
While wind maycurrently lead the way, some consider a number of technologies underdevelopment have more potential. In several cases, Australia is at theforefront of global research in the area. Some of them are very site-specific,ensuring that they may never become dominant market players. On the other hand,these newer developments are capable of providing more reliable power, avoidingthe major criticism of windmills –the need for back-up on a calm day.
F
One such developmentuses hot, dry rocks. Deep beneath South Australia,radiation from elementscontained in granite heats the rocks. Layers of insulating sedimentation raisethe temperatures in some location to 250°centigrade. An Australian firm, Geoenergy,is proposing to pump water 3.5 kilometres into the earth, where it will travelthrough tiny fissures in the granite, heating up as it goes, until it escapesas steam through another drilled hole.
G
No greenhouse gases areproduced, but the system needs some additional features if it is to beenvironmentally friendly. Dr Prue Chopra, a geophysicist at the AustralianNational University and one of the founders of Geoenergy, note that the steamwill bring with it radon gas, along through a heat exchanger and then sent backunderground for another cycle. Technically speaking, hot dry rocks are not arenewable source of energy. However, the Australian source is so large it couldsupply the entire country’s needs for thousands of years at current rates ofconsumption.
H
Two other proposals for very different ways to harness sun and wind energy have surfaced recently.Progress continues with Australian company EnviroPower’s plans for Australia’s first solar chimney near Mildura, in Victoria. Under this scheme, a tall tower will draw hot air from a greenhousebuilt to cover the surrounding 5 km2. As the air rises, it will drive aturbine* to produce electricity. The solar tower combines three very old technologies–the chimney,the turbine and the greenhouse –to produce something quite new. It is thisreliance on proven engineering principles that led Enviropower’s CEO, RichardDavies, to state: There is no doubt this technology will work, none at all.』
I
This year, Enviropowerrecognized that the quality of sunlight in the Mildura district will require asubstantially larger collecting area than was previously thought. However,spokesperson kay Firth says that a new location closer to Mildura will enable Enviropowerto balance the increased costs with extra revenue. Besides saving intransmission costs, the new site 『will mean increased revenue from tourism and use ofpower for telecommunications. We』ll also be able to use the outer 500 metres foragribusiness.』Wind speeds closer to the tower will be too highfor farming.
J
Another Australiancompany, Wavetech, is achieving success with ways of harvesting the energy inwaves. Wavetech’s invention uses a curved surface to push wavesinto a chamber, where the flowing water column pushes air back and forththrough a turbine. Wavetech was created when Dr. Tim Devine offered the idea tothe world leader in wave generator manufacturers, who rather surprisinglyrejected it. Dr. Devine responded by establishing Wavetech, and making a numberof other improvements to generator design. Wavetech claims that, at appropriatesites, 『the cost of electricity produced with our technology should be below 4cents per kilowatt-hour.
K
The diversity of formsof greenhouse -friendly energy under development in Australia is remarkable.However, support on a national level is disappointing. According to RichardHunter of the AEA, 『Australia has huge potential for wind, sun and wavetechnology. We should really be at the forefront, but the reality is we are along way behind.
Question 14-20
Do the following statements agree with the information given in Reading Passage 2?
In boxes 14-20on your answer sheet
14 In Australia，alternative energies are less expensive than conventional electricity.
15 Geo energy needs to adapt its system to make it less harmful to the environment.
16 Dr. Prue Chopra has studied the effects of radon gas on the environment.
17 Hot，dry rocks could provide enough power for the whole of Australia.
18 The new Enviro power facility will keep tourists away.
19 Wave tech was established when its founders we returned down by another company.
20 According to the AEA，Australia is a world leader in developing renewable energy.
Question 21-26
Look at the following statements(Questions 21-26) and the list of companies below.
Match each statement with the correct company，A-D.
Write the correct letter，A-D，in boxes 21-26on your answer sheet.
NB You may use any letter more than once.
21 During the process，harmful substances are prevented from escaping.
22 Water is used to force air through a special device.
23 Techniques used by other countries are being copied
24 The system can provide services other than energy production
25Itis planned to force water deep under the ground.
26 Original estimates for part of the project have been revised.
List of Companies
A Australian Hydro
B Geo energy
C Enviropower
D Wave tech