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A number of technologies exist for generating electricity from water. Of these, by far the most commonly found and most developed is that of hydro-electricity.65

61 For a discussion of the industrial processes of producing ethanol, see e.g. Renewable Fuels Association, Ethanol Production Process <www.ethanolrfa.org/prod_process.html> (accessed 20 July 2005); G Foley, The Energy Question, Penguin Books, London, 2nd edn 1981, at 239ff.

62 See B R Farrell, 'Fill 'Er Up With Corn: The Future of Ethanol Legislation in America' (1998) 23 JCorporation Law 373, at 376 and 391. In 1995, gasohol achieved a market share of 35% in Chicago and over 50% in Milwaukee.

63 See J Goldemberg, T B Johansson, A K N Reddy and R H Williams, Energy for a Sustainable World, Wiley Eastern Ltd, New Delhi, 1988, at 239ff; A de Oliveira, 'Reassessing the Brazilian Alcohol Programme' (1991) 19 Energy Policy 47.

64 See M Radetzki, 'The Economics of Biomass in Industrialised Countries: An Overview' (1997) 25 Energy Policy 545.

65 See <www.reslab.com.au/resfiles/text.htm> (accessed 18 January 2005); <www.worldenergy.org/wec-geis/publications/reports/ser/hydro/hydro.asp> (accessed 18 January 2005); UNDP et al, World Energy Assessment, at 251ff.

In some countries, such as the Philippines, hydro-electricity is responsible for the majority of the country's electricity resources. In Australia, for climatic reasons the actual and potential use of hydro-electricity is limited to Tasmania, the coastal fringes of northern Queensland and the mountainous region in the country's south-east. In terms of exploitation, hydro-electricity is the oldest of all the renewable energy resources and constitutes the majority of the 9% of electricity generated from renewables in Australia. It is principally exploited in Tasmania and the Snowy Mountains, the latter under an ambitious scheme financed by the Commonwealth government in the 1950s and shared between New South Wales and Victoria.66 The total hydropower capacity in Australia is 7.6GW, of which the Snowy Mountains Hydro-Electric Scheme constitutes 50% and Tasmania 30%.67

While hydro-electricity produces no conventional pollution or atmospheric carbon emissions its continued development has been a major source of controversy from an environmental perspective, both in Australia and overseas. Many major hydro developments have involved the displacement of indigenous people whose traditional lands become flooded.68 This has occurred most recently in China, where many thousands of people had to be relocated due to the massive 18.2GW Three Gorges dam project. In Australia, the problem has been not so much the displacement of people but the environmental damage caused by the drowning of large tracts of forest land. This issue came to a head in Tasmania both in the drowning of Lake Pedder and in the proposal to divert the Franklin River. While the Lake Pedder project went ahead in controversial circumstances, the Franklin Dam project was eventually halted by a 4-3 majority decision of the High Court of Australia in Commonwealth v Tasmania.69 Since then no further major hydro projects have been developed in Australia.

Other water-based renewable energy resources are ocean thermal energy conversion (OTEC), wave energy and tidal energy. All of these are still at the experimental stage in most countries, although tidal energy is exploited commercially at La Rance, France, and in the Bay of Fundy, Canada. OTEC involves the exploitation of the temperature differential between the warm water at the surface of the ocean in tropical latitudes and the cold water of the deep ocean. For effective operation of OTEC, the temperature difference between the warm surface water and the cold deep ocean water at a depth of 1000 metres must be approximately 20°C. This means that the surface temperature of the ocean near to the coastline must be a minimum of 27° C and the ocean bed must shelve deeply to the

66 The Snowy Mountains hydro-electric power scheme is the largest in Australia. It has a generation capacity of almost 3800MW. The scheme consists of seven power stations, two of which are underground, with 16 large dams and 145 km of tunnels: see <www.worldenergy.org/wec-geis/publications/reports/ser/ hydro/hydro.asp> at 6.

67 Department of Primary Industries and Energy, Renewable Energy Industry - Survey on Present and Future Contribution to the Australian Economy, AGPS, Canberra, 1997.

68 This problem does not occur in small-scale, 'run of the river' hydro projects. However, the scope for the exploitation of this resource in Australia is extremely limited. See <www.lowimpacthydro.org> (accessed 26 January 2005).

ocean depths.70 While a temperature of 27°C occurs in substantial coastal areas of Australia off Queensland, the Northern Territory and Western Australia, the coastline is too shallow to achieve the temperature differential required for the effective use of OTEC.71

Wave energy has been extensively trialled by the British government off the north coast of Scotland. The coastal area to the south of Australia offers a wave regime that is sufficiently strong to generate substantial quantities of electricity, but at present the costs of generation are hopelessly uneconomic. Substantial tidal resources exist off the north-west coast of Western Australia, particularly in the region of Derby. The problem here is the cost of the infrastructure that would be required to effectively exploit the resource as this area of the country is very remote from the main centres of human population in the south of Australia.72

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Getting Started With Solar

Getting Started With Solar

Do we really want the one thing that gives us its resources unconditionally to suffer even more than it is suffering now? Nature, is a part of our being from the earliest human days. We respect Nature and it gives us its bounty, but in the recent past greedy money hungry corporations have made us all so destructive, so wasteful.

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