POWER STATION SITING and URBAN GROWTH by M. HER TAN* and G.E

PAPER 11 " POWER STATION SITING AND URBAN GROWTH by M. HER TAN* and G.E. SMITH o 1. SUMMARY The future growth of urban development in Australia, together with a continued search for a higher standard of living and a better quality of life, would depend to a large extent on an increased supply of electricity. It is estimated that by the end of the century, the installed generating capacity in Australia would range between 80,000 and 120,000 MW which would be accommodated on some 50 to 80 large power station sites. The location of future power stations, however, is becoming increasingly more difficult. As the generating capacity installed at one site increases, the siting requirements, safety criteria and environmental considerations are becoming more complex. Furthermore, as the growth in urban development continues, the availability of suitable sites for large power stations with their associated works and various easments is becoming limited. ,- Co-ordinated planning in the use of available resources, together with a better understanding of our environment and technological advances in generation and transmission of electricity, should reduce some of the problems in future power station siting. .. 2. INTRODUCTION The locations of early power plants in Australia and many overseas countries were generally close to the community centres, supplying the energy needs of the small but developing populations. The power plants were small and,widely scattered about the newly formed cities, while the countryside had no electricity at all. With the growth of urban development, continuing rise in energy demand and rapid technological advances in transmission of electricity, the locations of major power stations shifted in increasing numbers from the load centres to the fuel sources. A new era of hydro-electric development and construction of mine-mouth coal burning plants in 1 remote locations came into being, while the supply of electricity spread throughout the country. •The continuing growth of modern cities, together with the availability of clean and 'mobile' fuels such as natural gas, and a growing acceptance of nuclear generation, are now gradually bringing a return of some of the newer power stations to the load centres. This trend would reduce the problems associated with the acquisition of transmission line easements and provide, in conjunction with the existing stations, a more balanced and reliable supply of electricity. The paper estimates the likely requirements for power station sites in the next three decades, examines the siting criteria for thermal plant installations, discusses the new constraints in the location of major power projects resulting from the growth in urban development and the concern for environment, and mentions some investigations being carried out overseas which, in the future, may alter the relationship between power station siting and urban growth. 3. URBAN GROWTH Demographic studies in Avstralia, United States, and other parts of the world indicate a trend of continuing growth in urban population and size of urban centres. Studies predict that the existing large cities would continue to grow along major transportation routes and eventually join with other nearby population centres to form wide urban corridors. (1)(2)(3) Assuming an average rate of growth of population of about 2% per annum, the existing population in Australia of about 12.7 million,, would increase by the end of the century to some 22.5 million. By that time, it is expected that the proportion of population living in large urban centres (more than 100,000 people each) would have increased from about 65% to about 82% of the total population with some 18!£ million people concentrated in the 15 largest cities in Australia, as shown in Table 1. It is evident *!iat as time progresses, the expanding population would continue to live, work and play close together, and all the stances associated with this population would form part of the same scene. The location of these * M. Hertan, Power Station Planning Engineer, Planning & Investigations Department, State Electricity Commission of Victoria. ° G.E. Smith, Section Engineer, Nuclear Investigations, Planning & Investigations'igations Department, State Electricity Commission of of Victoria. 1/ services, including generation, transmission and distribution of electricity, would become more complex, and co-ordinated regional planning would be needed for the optimum use of available resources such as land, fuel, water and, of course, men. 4. ELECTRICITY DEMAND The urban growth, based largely on industrial expansion and spread of technology, would depend to an increasing extent on use of electricity. The search for a higher standard of living, better quality of life and cleaner environment, would also require an increasing use of electricity. It is predicted that, in the years to come, electricity would have to play a bigger role in solving the problems of urban growth by operation of massive transportation systems, large waste control facilities and plant installations for creating a more pleasant climate. Although it is difficult to forecast a long-term rate of growth in electricity demand, it is anticipated that in the next few decades the electricity consumption would grow at a rate of about three to four times the increase in population, that is, some 6% to 8% per annum. Using these growth rates, the energy consumption in Australia of approximately 44,700 GWh in 1970/71 could range between 250,000 and 400,000 GWh per annum by the end of the century. By then, the electricity generated at power stations, after allowing for transmission and distribution losses, could range between 300,000 and 450,000 GWh per annum, as shown in Table 2. 5. POWER GENERATION 5.1 Generating Plant The development of an efficient and reliable electricity generating system must meet the exacting constraints resulting from a variable demand and a product which is difficult to store. Demand for electricity varies systematically with the time of the day and season, but is also subject to unpredictable weather changes, special domestic and industrial requirements, etc. The difficulty of storing electricity provides limited flexibility in the generating system, and careful planning is required to maintain the supply and demand of electricity in balance at all times. To meet these constraints, generation of electricity takes place in three main types of plant, designated broadly according to the load they supply; that is, base, intermediate, and peak load. Provision is also made for adequate system reserves to cover the routine and forced plant outages. Assuming an average annual load factor of 50% to 60% for the whole system and plant reserves in the order to 20% to 30% of maximum demand, it is estimated that the installed generating plant in Australia of about 15,000 MW in 1971, could range by the end of the century between 80,000 to 120,000 MW, as shown in Table 2. Based on these estimates, the installed generating plant in Australia should reach 100,000 MW within the next 25 to 32 years. The proportions of base, intermediate and peak load plants likely to be required by the end of the century are shown in Table 3. For this purpose, it is assumed that base load plants operate at more than 60% capacity factor per annum, intermediate load plants between 10% and 60% per annum, and peak load plants at less than 10% per annum. 5.2 Generating Stations The existing 15,000 MW (approx.) of installed capacity in Australia is located in 86 power stalion sites, and consists of more than 500 generating units. The total plant capacity exceeds 100MW at 36 sites and 500 MW at only 7 sites, as detailed in Table 3. The growth of electricity demand and its concentration in large urban centres, together with the growth of interconnection between the States, would enable larger units to be installed in the future and substantially increase the total plant capacity at one location. The growing constraints applied on the location of future power station sites and the high costs associated with the establishment of new generating projects confirm the world-wide trend towards the development of a small number of sites to their full potential consistent with the optimum utilisation of available resources and the ability to meet the environmental standards laid down by the appropriate authorities'. In Australia, generating units of 500 MW have already been ordered for use in Victoria and 660 MW in New South Wales while capacities Gf power stations have reached as much as 1.600 M Wat Hazelwood (Victoria) and should reach 2,000 MW at Liddell (New South Wales) in 1974. In the United States, generating units larger than 1,000 MW are being installed and power stations approaching 10,000 MW are being planned. (4) (5) It is anticipated that by the end of the century, power stations in Australia could have a capacity of 4,000 to 8,000 MW for base load plants., 1,000 to 2,000 MW for peak load plants and somewhere in between those extremes for intermediate load giants. Based on these assumptions, it is estimated that the number of new power stations required in Australia within the next three decades could range from about 50 to 80, as shown in Table 4. The proportions of power station sites likely to be required for base, intermediate and peak load installations are also shown in Table 4. , . :. - . -_ .-._- a-. _._s_...\: 6; POWER STATION SITING-THERMALPLANTS .:. 6.1 Siting Criteria * The power station requirements vary significantly with the fuel used, available water resources, method of integration into the existing transmission system, provision of services, environmental considerations and adopted layout. This paper has been limited to a few relevant aspects related to the siting of thermal power stations, (i) Fuel Fuel forms one of the major components in the cost of electricity generation and requires careful evaluation with respect to its production, treatment, transport and storage.

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