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PUBLISHER’S LETTER www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc.(Hons.) Technical Staff John Clarke, B.E.(Elec.) Peter Smith Ross Tester Jim Rowe, B.A., B.Sc, VK2ZLO Rick Walters Reader Services Ann Jenkinson Advertising Enquiries Leo Simpson Phone (02) 9979 5644 Fax (02) 9979 6503 Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Julian Edgar, Dip.T.(Sec.), B.Ed Mike Sheriff, B.Sc, VK2YFK Philip Watson, MIREE, VK2ZPW Stan Swan SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490 All material copyright ©. No part of this publication may be reproduced without the written consent of the publisher. Printing: Hannanprint, Noble Park, Victoria. Distribution: Network Distribution Company. Subscription rates: $76.00 per year in Australia. For overseas rates, see the subscription page in this issue. Editorial & advertising offices: Unit 8, 101 Darley St, Mona Vale, NSW 2103. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9979 5644. Fax (02) 9979 6503. E-mail: silchip<at>siliconchip.com.au ISSN 1030-2662 * Recommended and maximum price only. 2  Silicon Chip Australian power stations should be solar or gas-fired With the recent NSW government rejection of the proposed Redbank coal-fired power station in the Hunter Valley, it is clear that we are going to need some other solutions to our increasing energy needs. Before too long in New South Wales we are going to need some more power stations, maybe in only a couple of years. After all, we are not going to want to buy electricity from other states, even presuming that they will have any to spare. There is at least one other coal-fired power station proposal on the table, the one gigawatt plant at Ulan but given the decision on Redbank, it is unlikely to go ahead. At least, we hope not. But we need more thermal power stations otherwise we are going to have severe power shortages in years to come. So if not coal-fired, what is available? In the short term, the answer is gas-fired power stations as these have considerable advantages over coal. First, we have an abundance of natural gas and as well as selling it to China and elsewhere, we should be using it ourselves to generate power. It does not have the enormous cost of extraction associated with coal and it does not leave a huge scar on the landscape, as with open-cut mines and drag-lines. Granted, a pipe-line is needed to get the gas to the power station but even this has far less of an effect on the environment than rail or road transportation. But the real advantage of a gas-fired power station is the very big increase in efficiency brought about by the high temperature of the gases used to drive the gas turbines. After driving the turbines, there is still enough energy left in the high temperature exhaust gases to drive a boiler and steam turbine. Without going into thermodynamic theory, the efficiency is directly proportional to the difference between the heat source (ie, burning gas driving the turbines) and the heat sink (ie, essentially ambient temperature). In a gas-fired power station, the heat source temperature is much higher than in a coal-fired station, hence efficiency is higher. Not only that, the combustion products of water vapour and carbon dioxide are benign compared to those of coal. Nor are there huge piles of ash to be disposed of. So clearly, since we must have more thermal power stations, they should only be run from natural gas. In the long run though, we should be looking to solar power generation on a large scale. This is a project for federal and state governments. Considering the typical price of a large power station, a billion dollars or more, we could get a considerable solar generation industry off the ground in this country for that sort of money. The brief: build a 100 megawatt or bigger solar power station connected to the grid. The solar arrays are pretty straightforward and the electronics of the inverters needed to change DC to AC are hardly hi-tech these days either. Then there would be high voltage step-up transformers and a switchyard, plus high voltage transmission lines to connect to the grid. None of this is rocket science and after the first one was built, the following ones would be easy. So why not email or write to your local politician and help get the ball rolling. Leo Simpson www.siliconchip.com.au