Renewable Energy

An insight into the progress in renewable energy research

Renewable energy, also known as alternative energy, can be gained from such non-fossil sources as wind, sun and wave. The overwhelming majority of the world’s energy supply is still derived from fossil fuels now, say coal and natural gas, which are scarce resources. But according to a new report from International Renewable Energy Agency (IRENA), the costs of generating electricity from onshore wind have fallen by around 25% since 2010 while the costs of solar photovoltaic electricity by 70%. The report also indicates that all forms of alternative energy should be competitive in price with fossil fuels by 2020. In Australia, some modern technologies are aiming to be the first to push coal from its position as the country’s main source of electricity.

Currently, the front-runner in renewable energy is wind technology, which started to expand in the early 21st century. Peter Bergin, from Australian Hydro, one of Australia’s leading wind energy companies, points out there have been no remarkable changes in windmill design for many years. Still, the cumulative effects of numerous small improvements have made a difference to the costs. ‘We’re reaping the benefits of 30 years of research in Europe, without having to make the same mistakes that they did,’ says Mr. Bergin.

Electricity generated from coal is at around 4 cents per kilowatt-hour, but the environmen- tal costs are not incorporated in the price. ‘Australia has the second cheapest electricity in the world, which makes it difficult for alternative energy to compete,’ says Richard Hunter of the Australian Eco-generation Association (AEA). Nevertheless, the production costs of a kilowatt-hour of wind power have dramatically decreased during the last 20 years, according to the AEA’s report.

Australian Hydro possesses dozens of wind monitoring stations across Australia as part of its aim to become Australia’s pre-eminent renewable energy company. Despite all these developments, wind power remains one of the few alternative energy sources where Australia is nowhere near the global cutting edge, mostly just replicating European designs.

In spite of the leading role of wind in Australia, other technologies capable of providing more reliable power have more potential in the future. In several cases, Australia is at the forefront of global research in the area. One of such developments uses hot, dry rocks. In the deep layers beneath South Australia, radiation from elements contained in the granite heats the rocks. And the temperatures in some locations are raised by layers of insulating sedimentation to 250 degrees centigrade. An Australian firm, Geo Energy, is proposing to pump water 3.5 kilometres into the earth, where it will travel through tiny fissures in the granite, heating up as it goes, until it escapes as steam through another drilled hole.

No greenhouse gas is emitted, but the system needs some additional features if it is not going to have any detrimental effects on the environment. Dr. Prue Chopra, a geophysicist at the Australian National University and one of the founders of Geo Energy, notes that the steam will bring with it the radon gas, along through a heat exchanger and then sent back underground for another cycle. Hot, dry rocks are not a renewable source of energy in technique. However, the abundance of this resource in Australia could satisfy the entire country’s needs for thousands of years at the current rate of consumption.

Two other proposals for very different ways to exploit sun and wave energy have also been put forward recently. Progress continues with Australian company Enviro Power’s plan for Australia’s first solar chimney near Mildura in Victoria. This scheme makes it possible for a tall tower to draw hot air from a greenhouse built to cover the surrounding 5 km2. As the air rises, it will drive a turbine to produce electricity. Three very old technologies are applied to the tower – the chimney, the turbine and the greenhouse – to produce something quite new. The very reliance on proven engineering principles has led Enviro Power’s CEO, Richard Davies, to state: ‘There is no doubt this technology will work, none at all.’

This year, Enviro Power has recognised that the sunlight collection in the Mildura district requires a substantially larger collecting area than was previously thought. However, spokesperson Kay Firth says that a new place closer to Mildura will enable Enviro Power to balance the increased costs with extra revenue. In addition to saving the transmission costs, the new site will mean the increased revenue from tourism and the use of power for tele- communications. We’ll also be able to use the outer 500 m2 for agribusiness since the wind speed closer to the tower will be too high for farming.

Another Australian company, WaveTech, is achieving success by harvesting energy in waves, which has opened up a new prospect for alternative energy production. WaveTech’s invention uses a curved surface to push waves into a chamber, where the flowing water column pushes air back and forth through a turbine. WaveTech was created when Dr. Tim Devine offered the idea to the world leader in wave generator manufacturers, who surpris- ingly rejected it. Dr. Devine responded by establishing WaveTech and making a series of other innovations to generator design. WaveTech claims that, at appropriate sites, the costs of electricity produced with their technology should be below 4 cents per kilowatt-hour.

The diversity of forms of greenhouse-friendly energy under development in Australia is noteworthy. However, support on a national level is disappointing. According to Richard Hunter of the AEA, ‘Australia has huge potential for wind, sun and wave technology. We should really be on the front rank, but the reality is we are a long way behind.’

Questions 1 – 7

Do the following statements agree with the information given in Reading Passage 1?

In boxes 1–7 on your answer sheet, write

TRUE if the statement agrees with the information，

FALSE if the statement contradicts the information，

NOT GIVEN if there is no information on this.

1.Variations in windmill design have had a big impact on the environment.

TRUEFALSENOT GIVEN

2.In Australia, alternative energy is less expensive than conventional energy.
3.Geo Energy needs to adapt its system to make it less harmful to the environment.
4.Hot, dry rocks could provide enough power for the whole of Australia.
5.Enviro Power’s new facility will keep tourists away.
6.WaveTech was established when its founder was turned down by another company.
7.According to the AEA, Australia is leading the world in developing renewable energy.

Questions 8 – 13

Look at the following statements (Questions 8–13) and the list of companies below.

Match each statement with the correct company, A, B, C or D.

Write the correct letter, A, B, C or D, in boxes 8–13 on your answer sheet.

NB You may use any letter more than once.

List of Companies

A Australian Hydro

B Geoenergy

C Enviropower

D Wavetech