Power from the earth, energy from ocean waves & the world’s tallest structures full of hot air:New technologies from Australia unveiled [Archives:2004/802/Health]

December 27 2004

By Irena Knehtl*
[email protected]

Energy is and will remain the largest issue and business on Earth. The industry is undergoing major changes as the world grapples with climate change, pollution, the dependence on fossil fuels and the need for renewable energy.

Power from the Earth: Heat from the earth, stored and buried granites, and oil technology is the tool, water is the agent, and clean sustainable energy is the product.

Hot Dry Rock (HDR) geothermal energy or heat mining has recently been recognized as a new resource. It has a unique position within the renewable energy sector, for being capable of generating low coast, base-load power on a large scale. For Australia, it is a project of national importance: The experimental basin represents the largest known geothermal resource in the world and has the potential to supply 1000s MW of low coast power. This known resource has the energy potential equivalent to 50 billion barrels of oil. Economic studies show that HDR geothermal power technology has the potential and is competitive with fossil fuels. The cost of Australian historic well is proximately 5, 4 million Dollars.

HDRY does not depend on new technology. It relies on extracting heat from special hot granites at depths of less than 5 km from the surface, i.e. within the so-called “oil window”. The heat is extracted by means of circulating water from a deep surface well, through an engineered underground heat exchanger, with the hot water returning to the surface through the second well.

HDR geothermal electricity should be distinguished from conventional geothermal electricity, such as the power plants installed in the hot spring regions. Conventional geothermal energy is generated from naturally occurring hot water and steam in rocks near volcanic centers. This form of electricity production is well established in many countries. Conventional geothermal power stations are generally limited in size and are often linked to emissions of volcanic gases and toxic elements.

HDR geothermal energy generations differ from its conventional cousin below ground. It relies on artificially creating an underground heat exchanger to extract heat from high temperature locks by circulating water. It uses existing technologies equipment and skills that were developed for the oil and geothermal power generation industries. The simplest HDR plant consists of one injection well and two production wells. Water from the injection well flows through the underground heat exchanger developed within the hot rocks. The superheated water is brought to the surface under pressure and used to boil an organic liquid. The water cooled by the process is the re-injected into the underground heat exchanger in a closed loop, to extract more heat.

The organic vapor goes through a turbine to generate electricity..

It is thought that a small number of locations around the world have the right conditions for coast effective production of HDR electricity. For the best results, HDR geothermal electricity generation needs a large volume of the right kind of hot rock in the right geological setting. The best HDR energy source is high heat production granite that has naturally occurring radiogenic minerals, which produce heat. The heat needs to be trapped by an overlying blanket of insulting rocks, generally more than 3000 meters in thickness. Without such cover of younger rocks, the heat would be radiated away into the atmosphere and rock temperatures would be insufficient for cost effective HDR application. The objective is to produce electricity from its HDR geothermal resources on a large scale and at competitive costs. It intends to generate clean, emission – free power with the heat equivalent of 50 billion barrels of oil.

The pilot well has been named “The Habanero”, after the world's hottest chilli. In addition, hot it is! Outside of volcanic areas, these rocks are the hottest in the world. Hot-dry rock geothermal electricity production in Australia will be the deepest and the hottest well ever drilled on mainland Australia and also first deep geothermal well. It is Hot Dry Rock (HDR) technology what mineral grades are mining. Establishing the underground heat exchanger will open up the full potential of the excellent, high-grade HDR geothermal resource. It is part of the first step of achieving an emission-free base load electricity generator using renewable HDR geothermal energy.

Generating electricity from the Earths heat is not new. Countries like Italy, Iceland, New Zealand and Japan have bee doing it for up to a century, utilizing naturally occurring steam. In contrast, hot dry rock geothermal energy makes its own superheated water. Such power plans can only work where there are special geological conditions and very hot granite rock. This rock has to be no deeper than five kilometers as that is the current depth that oil-drilling equipment can comfortably reach. The granite has to be covered by a three kilometer thick blanker of insulating rocks so that the heat does not escape to the surface. The unique combination of resources offers the scope to produce large scale, renewable electricity at a lower cost than hydro, wind, biomass or solar alternatives.

Clean power is becoming a preferred priority for Australia. The Australian Government has passed legislation that allows incentives to be paid to approve alternative-power generating corporations. With the world attention focused on the finite oil reserves of the Middle East, the need for dependable renewable energy resources has never been stronger. If successful, Australia aims to become the largest renewable producer.

It is believed that HDR geothermal energy is at the same stage of development as natural gas was 30 years ago. It is expected that HDR geothermal will become an important energy source in the next then years. HDR geothermal energy generation may become even cheaper with the advent of advanced drilling techniques. With reserve equalling 50 billion barrels of oil, this is the most exciting and fastest-growing development project on Australia's power generation horizon. If they are right – and it looks as if they will be – this could be one of the greatest and most rewarding power plays of our time.

World Tallest Structure will be full of Hot Air

An Australian company plans to build five “power towers” over the next 10 years, altogether capable of providing electricity to a million households. Each of the proposed towers will be a kilometer high and 160 meters in diameter, and will producer electricity. The world first commercial solar convective “power tower” is expected to start producing electricity by early 2006. The huge 670 million dollar power tower has been already built. The first solar towers will product 200 megawatts of clean, emission-free electricity, sufficient to meet the power needs of 200.000 households. Just as the air inside a greenhouse is heated by the sun, air under the translucent collector will be heated and will flow towards the only available outlet, the chimney, like tower at speeds of up to 50 km/h. One single tower will meet about 8 per cent of Australia mandatory renewable energy target

And Energy from Ocean Waves

A revolutionary system of extracting energy from ocean waves has bee invented in Australia. It uses underwater air bag coupled to underwater compartments that circulate air. The systems are anchored to the sea floor, do not protrude above the waterline, and encourages marine life in the same way as an artificial reef. It uses a flexible air-filled membrane, which moves up and down as waves pass overhead. During compression, a valve opens and air is stored in a lower compartment. While existing wave energy devices use only par of wave's energy, this new systems achieves greater efficiency by focusing more of the wave energy on the device.

A prototype unit exposed to an 80 m wave front has the potential to produce 1.5 megawatts of electricity, which mean a production capacity of 13 million kilowatt hours per year – equating to enough electricity supply 770 to 1.026 homes.

Australia at a Glance

Australia is a stable society with a skilled workforce and a strong competitive economy. With the population of 20 million, Australia is the only nation to govern an entire continent and is the sixth largest country in the world in land area. As multicultural society, it includes indigenous peoples and migrants from some 200 countries. It has high-growth, low-inflation, low interest rate economy. The government sector is efficient, the labor market flexible and business sector competitive. It has made a significant investment in social infrastructure, including education, training, health and transport.

Australia's workforce of approx 10 million is highly trained. Almost half of them have university, trade or diploma qualifications. Because of major diversification in Australia's export base, Australia is now a commodity exporter; it has also sophisticated manufacturing and service industries. Although trade in commodities remains strong, new services and sophisticated manufacturing export markets have emerged. Japan, USA and Republic of Korea remain its largest export markets. Australia is also strong in information and communications technology, infrastructure, innovation systems, business environment and human resource development.

Cultural diversity has become a touchstone of Australia's national identity. One example is the growth of Islam in Australia. Muslims form an increasingly important part of Australia's diverse modern society, there were 281.576 Muslims at the last count…

Australia is committed to establishing a culture of innovation and to make the best use of national and international information networks, encourage creativity in all forms of research, promote collaboration between university researchers and industry.

Innovations, science, and technology are strong drivers of economic growth. More than half of Australian small and medium enterprises use the internet for B2B e-commerce. A third of the population are registered users of internet banking and mobile phone use if the fourth highest in the Asia Pacific Rim. E-government use is widespread, and a third of Australians have accessed public sector services online.

Tourism is one of Australia's largest and fastest growing industries. The number of short – term visitors grew during 2002-03 to nearly 5 million.

Australia's unique environment has many native plants, animals and birds that exist nowhere else in the world. Despite the vast size of the continent however, the majority of Australians live on the coast and in major cities – around 75 percent of Australia's population lives in urban areas. Australia is the driest inhabited continent on earth. Its interior has one of the lowest rainfalls in the world and above three-quarters of the land is arid or semi arid. These arid areas extend from the large central deserts to the Western coast. This has presented Australians with the challenge of how best to manage the variety of regions to meet the competing demands of agriculture, economy and conservation.

Yemen in Australia

Yemen and Australia are both founding members of Indian Ocean regional grouping for economic cooperation. Australia is an important trading partner to Yemen and supplier of basic commodities, such as wheat and meat.

Laying as it does, half way to and from Europe on logistical and transport route, an important trading partner to Australia, Yemen presents a number of opportunities worth exploring for innovative Australian investors and businessmen. In particular, in the field of manufacturing, products assemble product distribution.

A number opportunities for cooperation ranging from investing to joint undertakings exist in the field of agriculture, husbandry, fishing and tourism, in addition to oil, gas, mining and geothermal energy, exploration. Also transport and logistical connections, shipping lines and joint marketing exploration.

Extra remarks:

Explore Australian Innovations web site: www.industry.gov.au/publication/

Australia Travel Search: www.australiatravelsearch.com

Our appreciation and thanks go to the Deputy Head of Mission at Australian Embassy for providing valuable background information.

* Irena Knehtl is an economist and writer residing in Yemen. She is also a regular contributor to Yemen Times and had written tens of articles in issues raining from culture and society to economics and technology.