Inside front cover

Inside front cover

FRONT COVER One of the 500,000 volt transmission line towers carrying the two

highest capacity circuits feeding electricity to Sydney, NSW. Each

3-phase 4-conductor circuit can transmit the entire 2.64 gigawatt

electrical power output of the huge Eraring generating station near

Newcastle. The station has four giant coal-fired boilers delivering

steam to each of four enormous 660 megawatt turbo-alternator sets.

At full load this twin-circuit transmission line can supply roughly

half of Sydney's peak needs which amount to all the electricity

generated by….

Both Eraring and Bayswater coal-fired power stations,

totalling over five gigawatts.

Five nuclear power stations of one gigawatt output.

44,000 Kooragang wind turbines, provided that an efficient

means of storing electrical energy near the wind turbines is

available for when the wind is not blowing hard enough

(assuming 20% capacity factor).

1,200 square kilometres of solar panels, provided that an

efficient means of storing electrical energy is available close

to the solar farm for when the sun is not shining (assuming

17% capacity factor).

{one gigawatt = 1,000 megawatts = 1 million kilowatts}

Nuclear Electricity Gigawatts

Supporting Alternative Energies

Colin Keay, PhD, DSc

The Enlightenment Press

2002

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ABOUT THE AUTHOR

The author is a retired physicist and astronomer who, as an associate professor at the University of Newcastle for 24 years, taught basic thermodynamics and the principles of energy conservation and conversion of energy from one form to another. One of the challenges was to give students a good feel for relative amounts of physical quantities like energy and power and the distinction between them. All too often in news reports energy and power are terms used interchangeably, resulting in confusion by the public. And more often than not there is a gross miscalculation of the amount of either. This problem is much in evidence when intermittent energy sources (like solar and wind) are featured in the media. This booklet has been written to give readers a feel for the strengths and weaknesses of the many different ways of generating electrical energy - an indispensible commodity for the prosperity and good health of communities anywhere on this planet. The author has no past or present connection with the nuclear or any other energy industry. Other titles in this series are Nuclear Energy Fallacies - Forty Reasons to Stop and Think Nuclear Radiation Exposed - A Guide to Better Understanding Copyright ©2002 by Colin S Keay. All rights reserved. First published in Australia by The Enlightenment Press ISBN 0-9578946-2-7 Printed by Longworth & Goodwin Pty Ltd, NSW 2305

Victims of a Global Confidence Trick

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"Last week's (British) Government energy review, proposing a massive expansion in wind power to produce electricity, perpetuates one of the most bizarre confidence tricks of the modern world." So wrote a commentator in the London Sunday Telegraph of February 17, 2002. The article went on to reveal that Denmark, a world leader in electricity generation from wind turbines, has called a halt to their program on the grounds that it is too expensive and "has yielded no reduction in the emission of greenhouse gases". Furthermore, the article notes that "what is extraordinary is how successful the propagandists for wind power have been in creating the illusion that it is in any way environmentally friendly." This ground-breaking Sunday Telegraph article concluded "And who could seem more gullible than Mr Blair, falling for the great wind fantasy just when the Danes have recognised it as one of the silliest delusions of our age?" It has taken a long time to read in a national newspaper like the British Sunday Telegraph anything critical of alternative electricity production. As expected there were howls of protest from wind advocates, but those scientists and engineers, whose careful negative assessments of alternative energies have in the past been mercilessly ridiculed, are giving quiet thanks that the great global sustainable-energy bubble is at last showing signs of bursting. This is not to say that there is no place for wind power and other so-called renewable sources of energy. There is indeed a role for them, as we shall show. But there are very few practical options for generating reliable uninterrupted base-load electricity essential for powering a modern economy, such as Australia's. Expecting windmills and solar farms to provide base-load electricity is pie-in-the-sky, simply because the sun and wind are intermittent. The amazing thing is that so many otherwise thoughtful people have fallen for green misinformation and fail to realise that blackouts inevitably follow at times when electricity supplies are inadequate. Californians have been learning this lesson the hard way. In 2001 they were forced to cut domestic electricity consumption by ten percent because alternative energies failed to keep up with increasing demand. And increasing electricity demand is a global problem.

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Take a look at this set of electricity load curves for the State of New Sourth Wales. It plots the system load in gigawatts (thousands of megawatts) against the time of day 1:

To supply the daily peak load of nearly twelve gigawatts, the majority of the state's coal-fired power stations need to be in full operation. If alternatives are being relied upon for part of this load, say 20 percent, the stage will be set for power blackouts. Consider the evening peak in winter, the sun will have already set and the wind may or may not be blowing. Power cuts at that time will be most unpopular.

The Many Ways to Make Megawatts of Electricity There are many ways to take one or other source of energy and convert that energy into useful electricity. There are three primary sources of energy on this planet of ours:

sunshine from that giant reactor in the sky that we call the Sun, energy of radioactivity from the interior of the Earth,

and rotational energy of the Earth-Moon system. There is some evidence that oil and natural gas are also primary in the sense that they may have been bestowed from the formation of our planet from a cloud of dust and gas containing organic matter. Coal and peat on the other hand are derived from past solar energy. From whatever source they come, energy supplies have their merits and failings, requiring a careful evaluation which we shall attempt.

1 Source: Transgrid Annual Report 2001

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2

4

6

8

10

12

Summer

Winter

Minimum

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In assessing the relative outputs of various types of alternative energy we need a yardstick of some sort. A station producing an electrical output of one gigawatt (1 GWe), equal to a thousand megawatts, is one capable of making a significant contribution to the energy needs of a large city or a State. This is still short of the output of the largest Australian power stations such as Eraring or Bayswater which each generate 2.64 GWe (employing four 660 MWe turbo-alternator sets), a fact that should be remembered when comparisons are made. Also bear in mind that a power station does not have to have a power rating of 1 GWe. For example new, inherently safe, designs for nuclear power reactors can have much lower output ratings and be distributed closer to locations of electricity demand. The ten major contenders for electricity production discussed here have been rated against five significant criteria relevant to their base load performance. The more smileys awarded, the better they are: Cheap Electricity Cheaper electricity is certainly better Capacity Factor Proportion of time output is available Energy Payback Lifetime return on construction costs Economy of Area The less land demanded, the better Greenhouse Gas The less gas and pollution, the better. We commence by discussing the predominant method of electricity generation in the world today.

Coal

The profligate combustion of coal and oil during the past few decades is a major cause of the steady rise in global carbon dioxide levels, prompting fears of global warming due to greenhouse gas emissions. Fossil fuels, no matter how they are burned for heat energy, produce roughly twice their weight in carbon dioxide and release considerable volumes of other pollutants, including toxic trace elements, into the environment. In these respects natural gas is the least noxious fuel and coal the most, with oil pretty much in between.

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A 1,000 MWe coal-fired power station burning coal and operating at 75% capacity has a typical fuel requirement of 3 million tonnes of black coal a year. It pours into the atmosphere over 6 million tonnes of carbon dioxide, more than 100,000 tonnes of sulphur dioxide which returns to the environment as acid rain, and about 200,000 tonnes of particulates in the ash residue although a small amount escapes up the smokestack depending on the efficiency of the filters or scrubbers at the base of the stack. If brown coal is burnt the figures rise appreciably because more of it must be burnt to produce the same amount of electricity as from black coal. Worldwide, coal fired power generation consumes over 1,500 million tonnes of black coal every year. This leads to an annual emission of well over 3 billion tonnes of carbon dioxide, and if all other fossil-fuel electricity generation is included the sum total is around 7 billion tonnes per year. To appreciate the whole picture, the use of fossil fuels for all purposes - heating and transport mainly - raises the figure to 20,000 million tonnes a year of which around 45 % comes from coal and 40 % from oil. And it is still rising year by year which means that attempts to curb it have not been successful. One possible way is through the introduction of a carbon tax. In 1997 the Australian Conservation Foundation proposed such a tax at the rate of eight dollars per tonne which would add almost a quarter of a cent per kWh to everyone’s electricity bill, big industry and small consumer alike. Coal and oil are bulky fuels compared to uranium because their energy content is so much less. Whenever fossil fuels need to be transported an appreciable distance from the mine or well-head their conveyance generates further emissions to add to the above totals. Returning to the wastes from coal-fired electricity production, they arise because coal seams, over eons of time, have accumulated through precipitation a wide variety of minerals. The reactive organic content of coal creates the necessary conditions to trap these elements within the coal seam in recognisable streaks of thucolite, named after the radioactive thorium and uranium they contain. The annual wastes from a 1,000 MWe coal-fired power station include several hundred tonnes of toxic heavy metals such as arsenic, cadmium, lead, mercury, selenium and vanadium which retain their toxicity permanently, as well as the two radioactive elements in thucolite which have long half lives. The daughter elements they produce when they decay also

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contribute to the level of radioactivity in the ash. Radon gas is the daughter element with the greatest mobility and because of its highly active decay products it presents the greatest radiation danger to nearby population. Compared with other naturally occurring sources the radiation levels are not high, but are still over ten times higher than the emissions from a nuclear power station of the same capacity. It is interesting to note that a coal-fired power station discharges in its wastes more uranium than a nuclear power station consumes for the same amount of power if fast breeder reactors are used. Here are the facts: Australian coals2 contain from 0.4 to 5 parts per million uranium, with a mean of 2 parts. The energy released by the nuclear fission of uranium is more than one million times greater than the yield of chemical reactions such as coal-burning. So one tonne of uranium, if fully consumed in a breeder reactor, provides as much energy as more than a million tonnes of coal. That much coal releases more than two tonnes (average) of uranium in its wastes. This may come as a surprise to many readers but is well-known in the power industry. In order to avoid giving a false impression, the more common non-breeding reactors extract only two or three percent of the energy of the uranium fuel, so the ratio drops from several million to a few tens of thousands. This still means that, megawatt for megawatt, the uranium in the wastes from coal-fired power generating stations is considerable and is about as radioactive as unprocessed uranium ore. Before moving on, some coal-fired power stations in Australia have been used as incinerators of other wastes including garbage. Some 10,000 tonnes of contaminated soil, coal tar, used oil and other hydrocarbons a year were being mixed with ten million tonnes of coal and burnt at the Bayswater and Liddell power stations in the Hunter Valley. When this came to light it drew strong criticism from Greenpeace spokespersons concerned at its potential to cause cancers3. An Environmental Protection Authority spokesperson stated that the practice complied with clean air regulations. So the question is whether or not one should reclaim energy from the disposal of combustible wastes, and reduce coal demand correspondingly.

2 “Trace Elements in Australian Bituminous Coals and Fly-Ashes”, Swain, D J,

Coal Colloquium, Newcastle University, August 1979. 3 Newcastle Herald, 25 February, 6 and 7 March 1998.

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The reckless consumption of the world’s petrochemical resources for electricity production (and transport) represents an irrecoverable loss of feedstock for the needs of future generations in the areas of pharmaceuticals, plastics production and other organic chemical manufacturing processes. Cheap Electricity Capacity Factor Energy Payback Economy of area Greenhouse Gas OVERALL

Oil

Oil, for transportation and to some extent energy generation, accounts for roughly half of the global energy market. Petrol, kerosene and diesel fuels refined from oil are the mainstays of our transportation systems. Never mind the pollution they produce. For as long as oil is available land, sea and air transport will guzzle it. Natural gas supplements petrol and diesel for land transport and fuels derived, at some expense, from coal can substitute for oil to some extent. The question is, and again never mind the pollution, how long will the oil last? Well why worry? The world survived the oil crisis of the 1970’s and the cost of oil has risen by a factor of ten to around 25 to 30 US dollars a barrel at the present time. The question still is, and never mind the cost, how long will the oil last? To answer the question and get real we must seriously examine some figures, like rates of discovery and consumption. The rate of discovery of new oil deposits peaked around 1967 at 43 billion barrels a year. It has dropped to less than five billion (Fleay 1995). The good oil is getting harder to find. Annual global consumption is running at around 30 billion barrels a year, with demand increasing as world population rises. Oil is now being consumed at more than five times the rate it is being discovered. A worrying thought for motorists. The question remains, and it’s now a matter of reserves, how much longer will the oil last? At this point the ifs and buts take over. Campbell (1997) states that “At the risk of understatement, we may conclude that the world’s

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political and economic stability which relies on an abundant supply of cheap oil, is in serious jeopardy. In these circumstances it might be a good idea to determine what the reserves really are. It is more a political than a technical problem.” One vexing aspect of the political problem is the way that national oil companies exaggerate their estimates of oil reserves. Firm figures are difficult to glean but even the most optimistic experts in the industry expect the era of cheap oil must end before the year 2020. The more pessimistic forecasters like Fleay, on the basis of mid-nineties estimates, considered that cheap oil would be no more than a nostalgic memory by the year 2002. He forecast that oil price would then rise steeply, with serious impacts on transportation and energy production. This has not happened - yet. The only thing that can be said with any certainty is that the geopolitics of the twentyfirst century will be closely tied to the politics of oil and then move quickly toward the politics of energy supplies. Oil will be increasingly reserved for irreplaceable transport requirements.

Cheap Electricity Capacity Factor Energy Payback Economy of area Greenhouse Gas OVERALL

Natural Gas

Natural gas is seen, with hydroelectricity, as a logical partner to the intermittent alternative energies such as solar and wind power. Like a hydroelectric station the power from a gas turbine electricity generator can be brought online in a matter of minutes and carry a load until the wind picks up or sunshine returns. Because of its high methane content, giving a lower ratio of carbon to hydrogen, natural gas reduces carbon dioxide emissions by about one third. Also, depending on the source of the gas, other pollutants such as sulphur are lower than for other fossil fuels. Like coal-burning, natural gas releases the radioactive daughters of any radon it contained at the well-head, although their activity is reduced by length of residence in storage tanks and pipelines where they are deposited. Natural gas does, however, provide a significant contribution to world electricity generation. In the United States alone electricity utilities

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have installed about 50 GWe of gas turbine equipment, some of it burning kerosene fuel but capable of using natural gas if it is locally available. Recent data from the World Energy Council shows that the use of natural gas is expanding very rapidly in several European countries, as well as in developing countries. Over 1990-96, carbon dioxide emissions from natural gas rose 23% in OECD countries while developing countries burned 61% more natural gas in 1996 than in 1990 (UIC 1997). It might be called 'galloping consumption'! In western Sydney, motorists travelling along the Cumberland Highway can hardly miss seeing the three large exhaust stacks of Sithe Energy's 162 MWe cogeneration plant4. This exemplary facility has three General Electric 38 MW turbo-generator sets powered by natural gas. The exhaust heat is harnessed to power a steam turbine producing a further 65 MW. The low temperature spent steam is then piped next door to supply the needs of a paper recycling mill. This is the cogeneration aspect of the operation. Cheap Electricity Capacity Factor Energy Payback Economy of area Greenhouse Gas OVERALL

Biomass

This is essentially a combustion process, where gas from decaying garbage is collected and burnt to provide energy. The gas is very similar to the natural gas associated with coal and oil deposits, being mainly methane. Methane is itself a contributor to the greenhouse effect, and the product of its combustion is water and carbon dioxide. So one greenhouse gas is consumed to produce others! Whether the whole process is greenhouse-neutral or not calls for closer analysis. However the methane produced by the decay of garbage represents a source of energy that might just as well be utilised, especially if it saves the burning of valuable fossil fuels. Another such source is the anaerobic digestion of sewage by appropriate bacteria, producing enough methane to run the sewage treatment plant. Unfortunately the amount of energy generated is nowhere near enough to meet the

4 Fact Sheet, Sithe Energies Australia P/L

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needs of the community supplying the sewage. Beckmann (1979) colourfully suggests that the power from garbage is little more than needed to power the presses that print garbage about power from garbage. Wood burning falls under the heading of biomass. Its contribution to environmental pollution makes it one of the least desirable fuels for energy generation. From the greenhouse perspective it is far better to preserve and plant trees wherever possible. Even burning dead wood is not such a good idea but often it is the only option where the natural processes of rot and decay, which releases methane, are impractical. Such a facility is the waste wood power generation station at Kettle Falls in the American State of Washington which produces 42.5 MWe. It, of course, produces substantial carbon dioxide emissions. In Australia the Broadwater Sugar Mill produces more than five megawatts of exportable electricity by burning cane residues (bagasse) and through cogeneration supplies the process heat for the mill. The energy value of the annual bagasse production from sugar factories in northern Australia amounts to nearly a billion billion joules (AEN, No 7, 1998) or a massive 30 million MWh of thermal energy. On a global scale less than two percent of world consumption is supplied from non-commercial biomass energy sources, such as wood, shrubs, agricultural wastes and animal dung. These require no capital investment, only labour. Alcohol (mainly methanol) from wood and plant fermentation processes can augment transportation fuels, but its production costs will remain against it until fossil-fuel prices rise well above their present level. For fuel production on a large scale the amount of land required is excessive and at the expense of food production. In many cases the amount of energy consumed in the production of the alcohol is more than it supplies through its combustion (Waltar 1995).

Cogeneration

This is not so much generation of electricity as the reclamation of energy which would otherwise be wasted. Large industrial enterprises often require vast quantities of high temperature heat that is dumped to the environment after it has performed its role in whatever process is involved. Instead, using cogeneration methods, it may be harnessed to generate much or even all of their electrical requirements.

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Examples of such industries are pulp and paper mills, sugar mills, petrochemical refineries, breweries, fertiliser plants and even large hospitals. An industry association formed to promote cogeneration estimated in 1996 that about 1000 MWe was already being produced in this way and that cogeneration has the potential to take care of 25 percent of Australia’s electricity requirements. Because the electrical power is generated at or near where it is needed there is a saving in transmission costs. And it has the great advantage in the current greenhouse gas situation that its savings can be realised very promptly.

Fuel Cells

A fuel cell is a means of obtaining electricity directly from a chemical reaction. It is the opposite of the process of electrolysis, in which an electric current passing through water, for example, breaks the water down into its chemical constituents hydrogen and oxygen. Hydrogen is given off at the negative electrode and oxygen at the positive. Unfortunately it is very much harder to design an electrolytic device which can operate in reverse and produce electrical energy. For several decades fuel cells were specialist devices for use in critical applications such as manned spacecraft. However they are gradually becoming a commercial proposition as units of up to half a megawatt capacity are achieving enviable performance figures. They can run on anaerobic digester gas from sewage treatment works, gas from landfill dumps, and they offer the cleanest and most versatile means of converting natural gas and gasified fossil fuels to electricity. Whatever combustible gases are used, they must first be cleansed of chlorine and sulphur compounds before feeding to the cells otherwise they ruin the semi-permeable membranes necessary for them to work. On the other hand the exhaust gases from fuel cells comprise very pure carbon dioxide as well as water vapour which can be condensed and used in many applications. If the emerging molten carbonate fuel cell technology matures, and large capacity systems (50 to 250 MWe at better than 50 percent efficiency) become feasible they could cut carbon emissions by about one third with no sulphur or nitrogen oxide pollution. The outlook is good because fuel cells can be scaled upward in size to enable compact power stations of large capacity to

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be built having the capability of generating reliable base-load electricity (at the expense of carbon dioxide emission). A small company in Massachusetts, Ztek, is challenging the large manufacturers with an innovative design which greatly reduces the size of their solid-oxide cells to the extent that a stack of sixteen is only 2.5 cm in height. Hundreds of them packed together comprise Ztek’s basic 25 kW unit. Running silently off natural gas, fifty of these units coupled together can supply over a megawatt of electrical power and still be compact enough to be transportable by a single semi-trailer. In this country the first significant use of fuel cell technology is at the Australian Technology Park at Redfern, in Sydney. An American ONSI 200 kWe unit about the size of a shipping container produces electricity from natural gas. The ONSI fuel cells are very reliable, achieving an operating availability of over 95 percent, with early models still supplying power after more than 40,000 hours. They operate between 100 and 200 degrees C which gives them excellent cogeneration capabilities, supplying plenty of steam or hot water for use in addition to the power output. Their thermodynamic efficiency is superior to gas turbine systems and diesel-electric generators which means that the greenhouse gas emissions from fuel cells are lower per kilowatt power output. Costing over $5,000 per kilowatt, the Redfern installation is not exactly cheap, but prices are set to fall as the technology matures. Cost is the main reason why, after four years of trouble-free operation, the Redfern installation remains the only one in Australia. A contest is on in the automotive industry to develop an efficient car powered by fuel cells, preferably using hydrogen as fuel in order to achieve the holy grail of zero-emission figures. The use of fuel cells offers hope to defeat the limited range and long recharge times that plague present-day battery-powered cars. A summary of progress in battery and fuel cell design with prospects for use in powering road vehicles is given by Kendall (Physics World, 2002). General Motors engineers have been working on a prototype car to run on a fuel cell powered by methanol, while Ford is less advanced. They consider that cars powered by fuel cells are more than a decade away. Some private companies are more optimistic. A two-seater “Green Car” developed in Florida several years ago used two ten-kW

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solid polymer hydrogen fuel cells capable of powering it to faster than 140 km an hour, and giving it a range of 200 km. Since 1995 wealthy golfers in southern California have been getting around on and off the golf course in buggies powered by hydrogen fuel cells. If you visit Vancouver you may be lucky enough to travel around the city on one of their Canadian-built Ballard hydrogen-powered buses. Chicago is also testing the Ballard buses and hopes to equip its commuter fleet with two thousand of them. The overall efficiency for vehicles powered by fuel cells is about three times better than for those with internal combustion engines, and they do not require pollution control measures.

Cheap Electricity Capacity Factor Energy Payback Economy of area Greenhouse Gas OVERALL

Solar Power

There are several distinct ways of harnessing solar energy. One may simply gather its heat. Another is to cause it to produce a current flow in a solar cell. These are usually called thermal and photovoltaic methods respectively. Both are limited by the dilute nature of solar energy and "it is important to realise that solar is most available when it is least wanted, in summer; and solar energy is least available when it is wanted most, in winter" (Hoyle 1980). Above the Earth’s atmosphere the total amount of energy over the whole solar spectrum amounts to 1.36 kilowatts per square metre and the radiation spans almost the entire electromagnetic spectrum. After the sun’s rays have passed through the atmosphere their total energy is reduced through absorption by hazes of various origins. Under clear skies in the tropics the solar energy density may approach one kilowatt per square metre and its spectrum ranges from the ultra-violet rays which can give an exposed person severe sunburn, through to the infra-red rays which are felt as heat. The energy falls away dramatically at higher latitudes due to the lengthened path of the sun's rays through the atmosphere and hence greater absorption loss. Thus the usefulness of solar power varies greatly from country to country, meaning that solar panels performing well under Australian

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conditions would be totally inadequate in northern Canada. Similarly, along the Arctic seaways where the Sun rarely shines, the Russians have been obliged to employ radionuclide power units for their radio beacons and lighthouses (Tsipenyuk, 1997). In our discussion of solar energy, the figures will apply for locations at around 35 degrees latitude, the Sydney-Newcastle region of New South Wales, Australia, to be specific. They would also be appropriate for Los Angeles, Athens, Tokyo, Buenos Aires or Capetown.

Thermal solar power

There are many ways sunlight can be used to provide low-grade heat. Suitable building design is one which is all too often ignored. If we consider temperate latitudes where most of the global population lives, it is not very difficult to design a dwelling which is warm in winter and cool in summer. Unless, of course, the building site is hopelessly shaded by tall structures, dense trees or steep terrain. The trick is to take account of the different path the Sun takes from season to season as it passes across the sky. Maximise the window area facing the equator, and minimise it in other directions. Provide an overhang that shields the summer sun but allows deep penetration of winter sun onto a stone or concrete slab floor. Done properly, the results can be astounding. I once designed such a house and made provision for oil heating in case more heat was needed on cold frosty nights. The oil heater never needed to be installed. It could be a very wise move for building regulations to mandate the adoption of solar-efficient designs in all future dwelling construction. Done sensibly it need not add much to the cost of a house and in some instances could even reduce the expense. Besides space heating, solar energy is also good for providing hot water. For a cost of A$3,000 (with $1,500 "green" rebate)a solar water heater of four square metres area can provide up to 5 kWh per day in winter to more than ten kWh per day if sensibly oriented at a latitude of 35 degrees. This amounts to 2.5 MWh a year and represents an annual saving on power bills approaching A$250. With a 300 litre storage tank the needs of a family of four can be met with only a small amount of external power being drawn during the winter months. For a state or region with one million homes, the universal

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adoption of solar hot water installations could save approximately 300 MWe of electricity generating capacity - a significant contribution. However the capital cost of three billion dollars would be borne by the individual householders. By using curved mirrors solar heat can be concentrated and focussed on a boiler where much higher temperatures may be reached than with unfocussed sunshine. In some parts of the world this method has been used for metal smelting. In other places it has been used for electric power generation. One such place was the small isolated town of Whitecliffs in New South Wales. In 1979, as a feasibility project by the Australian National University, an array of fourteen three-metre wide dish mirrors was erected at Whitecliffs to provide electricity for the community of about 150 people. The mirrors tracked the sun by day and back-up diesel generators took over at night. The cost of the solar power was half that from the diesel generators. However it was almost a full-time task to keep the mirrors clean and operating efficiently and in the final analysis sunshine provided at best ten percent of the power demand of the Whitecliffs community. Although the installation was quite a tourist attraction it was closed down in 1989 after operating for a decade5. Whitecliffs is now connected to the State electricity grid system. Cheap Electricity Capacity Factor Energy Payback Economy of area Greenhouse Gas OVERALL

Photovoltaic solar power A number of substances, such as cadmium sulphide, have the ability to convert light into electricity when fabricated into a thin film with contact electrodes to convey the current away from it. Great leaps in efficiency have recently been made, notably by a team at the University of New South Wales, by fabricating photovoltaic solar cells from silicon semiconductor material similar to that used to make the chips in computers and high-tech electronic devices. For solar cells,

5 “Lights out for `sun town’ plant”, The Australian, 4 Nov 1989.

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the silicon is cleverly laced with selected impurities and formed into thin sheets with electrical contacts etched into their surfaces. Efficiencies of around 24 percent have been achieved. That translates to about 200 watts of electricity per square metre in direct sunlight at low latitudes. Cells having that level of efficiency are, as might be expected, relatively expensive. However they are in demand where cost is a minor consideration, a good example being the solar-powered cars competing in the annual Darwin to Adelaide race for that class of vehicle. The usual energy conversion efficiencies of solar cells is in the region of 11 to 16 percent. The world record for conversion efficiency is around 35 percent, for a tri-junction cell devised at the University of New South Wales, closely followed by 33 percent for a tandem cell developed by the Boeing Corporation. A photo-voltaics researcher at the University of New South Wales, Bob Largent, frankly conceded that “solar energy was likely to cost five times more per kilowatt hour than power supplied from the grid”6. However the great advantages of solar cells for stand-alone applications, like solar cars, remote telemetry transmitters, space satellites and a host of other uses, outweigh their high capital cost for those applications. In the latest (2000) catalog from Australia’s leading commercial supplier of solar cells the largest panel available costs A$815. It supplies a maximum power of 83 watts (17 volts and 4.9 amperes of direct current) when full sunshine falls perpendicularly on its surface area of three-quarters of a square metre. This does not include the costs of mounting the unit, regulating the electrical output or conversion to alternating current for transmission over a power grid7. From the above figures one can easily calculate that twelve million of these solar panels would be required to equal the power generated by our standard 1 GWe power station, and then only when the Sun is high in the sky and the sunlight is falling perpendicularly on the face of every panel. The amount of time during which this power level can be sustained averages about eight hours a day if the panels are continuously swivelled to follow the Sun. This is a complication adding very considerably to the cost of the installation. If the panels do not follow the Sun the output is roughly halved when a daily

6 Australian Personal Computer, Vol 19, No 2, p58, 1998

7 'Going Solar' Catalog and price list, 2001

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average is taken. Naturally the output is further reduced on cloudy days. So, neglecting cloudy weather, and assuming some form of large-scale energy storage to tide consumers over the night-time lack of electricity from the dormant solar array, we find that 72 million panels will be required to match the reactor output. These will cover an area of 96 million square metres, or 96 square kilometres. That is to say, a farm roughly ten kilometres square. The costs must include inverters to change the direct current from the panels into alternating current for onward transmission, and of course the necessary transformers, circuit breakers and transmission lines themselves. If bulk manufacture reduces the panel cost to only one quarter of the catalog price, that is to say two dollars fifty a watt, the cost will still be in excess of three billion dollars for the solar cells alone, with not much change left out of five billion dollars when Sun-tracking mechanisms, and all of the electrical equipment are factored in. This, remember, is for a solar power producer providing its rated output for only one third of the time at best! Having said that, Australia has plenty of poor quality land where very extensive solar farms, covering tens if not hundreds of square kilometres, could be established without alienating precious arable land. Unfortunately such sites are well away from most consumers and the necessity for long transmission lines and related equipment could easily double the overall cost. “The world is on the brink of a clean energy revolution” claimed the New South Wales Minister for Energy in March 1998 when he officially opened at Singleton the largest solar energy farm in the southern hemisphere. At a cost of two million dollars its 3456 solar panels spread over 1.5 hectares feed 400 kilowatts of electricity into the State power grid - when the sun is shining full-on to the panels fixed at 30 degrees elevation. The total cost was over $2 million. At the official opening it was claimed (and the news media echoed) that the farm would provide power for 3,000 households. That works out at 133 watts per home - when the sun is shining - which is about one sixth of the amount necessary to run an electric jug to boil water for a cup of tea. Even so, a development such as the Singleton solar farm is highly valuable because it is in effect a large-scale pilot project that will yield

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firm figures on the economics, reliability and usefulness of solar power generation using photovoltaic devices. Some of the disadvantages of solar farms here on Earth are overcome by placing them in space. In the 1960's Dr Peter Glaser advanced the concept of building solar power stations in space where sunlight is continuous and unattenuated. Placed in geosynchronous orbit like most comsats the powersat could deliver electrical energy by microwave transmission to an array of receiving antennae at ground level. In 1973, Glaser presented his scheme to a US Senate Committee, and two years later an experimental test of bulk power transmission by microwaves over a distance of a mile was successfully carried out in California. It was thought that the structures for a five gigawatt powersat could be carried into low orbit by space shuttles then boosted into geosynchronous orbit by additional rocket stages. But the heavy demand and cost of shuttle transport consigned the scheme into limbo. It was a case of the cost outlay exceeding the returns. However the Japanese are actively seeking to diversify their energy sources by looking toward powersats. By the year 2040 they hope to have their first one-gigawatt powersat in operation, delivering microwave power to a receiving array several kilometres in diameter built above the sea. Their powersat will weigh 20,000 tonnes and cost the better part of twenty-billion US dollars. This will price their delivered power at least four or five times the cost of fossil or nuclear electricity. Unlike solar farms the power from space will be available 24 hours a day, except for brief outages twice a year when the powersat passes through the Earth's shadow and is eclipsed. Finally, a word about the frequent description of solar power as clean power. During operation this is true. However experts on the subject point out that the chemical carcinogens in wastes from the manufacture of photovoltaics for solar energy generation are many times more harmful than the nuclear waste produced through the generation of the same amount of electrical energy (Cohen 1990). Cheap Electricity Capacity Factor Energy Payback Economy of area Greenhouse Gas OVERALL

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Wind Power

There’s something about wind farms that fascinates people. They can almost feel the power churning out from the huge blades whirling hypnotically in a stiff breeze. One of the largest windfarms in the southern hemisphere is at Ten Mile Lagoon, near the town of Esperance in Western Australia. Since coming into operation in 1993 it has proved to be a significant tourist attraction. It has nine 225 kW Danish wind turbines, with diesel backup which is absolutely essential since the Esperance region is not connected to the State power grid. The entire project cost $5.8 million. An earlier wind farm not far away began operation in 1989 with six smaller wind-turbines manufactured in Perth. Its success stimulated the new installation using larger and more efficient Danish turbines. The largest wind-turbine in the world is a 3.2 megawatt unit at Kahuku in Hawaii. The blade diameter is 97.5 metres - the length of each blade is 48 metres (not including the hub) compared with the wing length of 28 metres for a 747 jumbo jet! This must be close to the practical upper limit for fabricating blades strong enough to withstand the stresses imposed by wind gusts. A wind farm with smaller, more robust units would seem less vulnerable. There’s also something about wind power that makes people wax just a trifle over-enthusiastic. On the day in 1997 when Australia’s largest wind turbine was assembled on Kooragang Island, near Newcastle, the evening TV news8 interviewed an Energy Australia spokesman who proudly announced that the Danish Vesta 600 kilowatt installation would produce enough electricity for 6,000 homes. Six thousand? That works out at one 100-watt bulb per home! A few weeks later, at the official opening ceremony, the parliamentary secretary to the Minister for Energy, said “it would generate enough energy to supply about 4,000 customers...”9. That now equates to two 75-watt bulbs per customer! According to a Newcastle City Council State of the Environment Report the average domestic electricity consumption per household in the Newcastle Area is 5,500 Kilowatt-hours per annum. This works out at 620 watts per household averaged over a whole day. So the

8 NBN TV 1st November 1997.

9 Newcastle Herald, 25 November 1997.

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Kooragang 600 kilowatt generator could theoretically supply the needs of just under 1000 homes. Not 6,000, or even 4,000. But wait. No account has yet been taken of the wind turbine’s overall efficiency, because the wind does not blow all the time. Some weeks previously the project manager for the Kooragang turbine revealed its expected efficiency (capacity factor) to be 36 percent. If so, that figure reduces the number of homes supplied to 350. Or to put the situation another way, 970 homes could be supplied by wind energy provided the occupants were happy to have either reduced supply or no electricity at all for 64 percent of the time! Another figure frequently cited in the media is that the Kooragang wind turbine will generate `over a million kilowatt-hours of energy per year’. Sounds impressive. Again using the Council’s figure for the average home electricity consumption as 5,500 kilowatt hours per year and dividing this into the figure of over one million kilowatt hours shows that the number of homes that could be supplied entirely by power from the wind turbine is around 200, an estimate rather less optimistic than the figure of 350 homes derived earlier. Whichever way you look at the matter, the revised figure is only a fraction of the touted 6,000 homes that the wind turbine was said to be able to supply. It strikes me as interesting that alternative energy enthusiasts very frequently over-estimate the productivity of their pet technology. Maybe its because we live in an age of advertising hype. Returning to the Kooragang wind turbine, its published power output as a function of wind speed is shown in the following table.10 4 metres/sec (14 km/hr) Start-up wind speed 6 metres/sec (22 km/hr) Delivers 77 kW 8 metres/sec (29 km/hr) Delivers 206 kW 10 metres/sec (36 km/hr) Delivers 371 kW 12 metres/sec (43 km/hr) Delivers 514 kW 16 metres/sec (57 km/hr) Delivers 600 kW 20+ metres/sec (72+ km/hr) Automatic shutdown From the table we see that the rated power is delivered only when the wind speed is between about 50 km/hr and 70 km/hr. Near the design limit of 72 km/hr, wind gusts cause sudden shutdowns which

10

P Myors, Newcastle Herald, 28 Oct 1997.

22

render the supply very intermittent. Large wind farms tend to reduce this problem somewhat since gusts don’t strike every wind turbine simultaneously. The above table allows one to apply the annual wind statistics from nearby Williamtown airbase to the Kooragang wind-turbine revealing its efficiency to be about half of the 36 percent expected. In fact, from the time its blades began to turn, the average annual output of 900 MWh shows its efficiency (capacity factor) to be close to 17 percent. The country with the greatest investment in wind power is Denmark, where ten percent of their electricity is derived from wind-farms that achieve a capacity factor of 20 percent. The total global production of electricity from the wind is currently a little over 20 gigawatts, which is less than twice the total coal-fired generating capacity of the State of New South Wales. It could be provided by twenty of our standard power stations rather than tens of thousands of wind turbines. Sustainable energy gurus seldom mention that wind power is a highly unreliable electricity source without power back-up of some kind. Consumers demand continuity of supply. This makes it essential for wind farms to operate in conjunction with diesel back-up or base-load power generation, whether it be fossil-fueled, hydro or nuclear, where the turbo-generators are kept spinning to take up extra load at literally a moment’s notice when the wind fails - or blows too hard. The weakness of wind and solar power is that they are both dilute and intermittent. Thus they can contribute only a few percent of the power demand in any large-scale distribution system. To appreciate the inadequacy of wind power as anything other than a supplementary source of electricity consider the extent of a wind farm required to substitute for our standard one-gigawatt power station. If the wind blows steadily at 60 km/hr and the turbines operate at their maximum power of 600 kWe, 1,667 of them will be required. But the wind does not blow continuously, or always within the correct speed range. Taking into account an overall efficiency of, say, 20 percent we find that 8,330 units will be needed. Where large wind turbines are placed closer together than about half a kilometre they suffer a shadowing effect which reduces their output. Let us be as fair as possible and suppose that their rows can be staggered to allow nine per square kilometre. The 8,330 wind turbines would then occupy 926 square kilometres. More than ten times that

23

area would be needed to equal the existing generating capacity in the Hunter Valley alone. At a unit price-tag of 1.5 million dollars, the cost of the 8330 wind turbines in this huge wind farm would be over 12 billion dollars, rising to well over that figure when taking into account the costs of linking them all electrically and connecting the array to the main grid system. These, and the other downsides of wind power are rarely publicised, and dismissed whenever they are. Bird strikes are frequent, especially when the blades whirl in the close vicinity of a bird sanctuary, as at Kooragang Island. I read somewhere that the Audubon Society is becoming alarmed at the number of rare raptors killed at the extensive wind-power farms which supply one percent of California’s electricity. According to figures released by a British anti-windfarm organisation there were 300 raptors killed in 1989 alone, and many more wind-turbines have been erected since then. Wind Power Monthly in February 1994 reported that the corpses of birds of 13 protected species had been found under the wind-turbines at Tarifa in Spain. It would be interesting to discover the bird toll from the Kooragang installation where large numbers of migratory birds visit its location. Noise from the turbine blades is said to be a problem for up to one and a half kilometres from a wind turbine. That may be true for earlier designs. The modern Kooragang wind turbine is very quiet and its soft swishing is easily drowned out by the sounds of traffic nearby. Under perfectly quiet conditions it might be more intrusive. As with aircraft noise, some people are bothered by it - others are not. Likewise for the visual impact of a wind turbine. It is claimed that properties near wind-farms have been dramatically reduced in value. These and other fears are presented in fact sheets distributed with petitions and enrolment forms by such groups as Britain’s `Country Guardian’ or the Welsh `Campaign for the Protection of Rural Wales’ and their `Friends of Black Hill’ group. Visit the World’s largest assemblage of second-hand bookstores at Hay-on-Wye, in the shadow of Black Hill, and you will find petitions to sign in many shop doorways protesting further intrusion of wind-farms. With more than 400 whirling windmills dotted along their skylines, Wales has the most wind turbines of any region in the British Isles.

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Recently (early 2002) the British anounced a major expansion of their wind energy program, with thousands more turbines planned for their windswept north. Germany, too, is building more. However Denmark is calling a halt to their program which has given them the dearest electricity in Europe. Returning to the Australian scene, a 4.8 MWe commercial wind farm has been constructed near Crookwell, in New South Wales 50 km northwest of Goulburn. It takes advantage of a 66 kV transmission line which runs across the site and electricity has been fed to the grid since 1998. Energy costs as low as 6 cents per kWh were expected (AEN, No 6, 1997) but this a yet another pie-in-the-sky figure. Over a period of two hours on the calm, sunny day when I visited Crookwell only one of the seven wind turbines was sluggishly turning to produce only a trickle of electricity - if that. This brings us to a significant problem with wind power that is rarely discussed. It is an electricity grid load manager's nightmare. It is bad enough coping with fluctuations in demand that require calling online extra generating capacity, or reducing it, but random variations in supply compound the problem of maintaining a stable voltage. This need is the reason why FPL Energy, America's leading wind energy generating company, has purchased a 1161 MWe nuclear reactor11. Whether or not wind farms become a significant adjunct to electricity generation in Australia, there is certainly a place for wind-power in the overall energy scene. It is well-suited to pumping water (which only needs to operate on an intermittent basis) and for supplying power in certain situations, such as for isolated communities. It seems to have been forgotten that Australia was once a world leader in generating electricity from the wind. In earlier years of the 20th century, 'Dunlite’ wind-driven generators kept the batteries charged on many outback stations to provide enough power for radio communications and a modest amount of lighting. Cheap Electricity Capacity Factor Energy Payback Economy of area Greenhouse Gas OVERALL

11

UIC Newsletter #3 May-June 2002

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Hydro Power (and reverse storage)

Hydro-electric power production, which accounts for three percent of the global energy supply, is a renewable resource with a low greenhouse gas liability, arising from drowned vegetation and the manufacturing processes of the required materials. After construction is completed there are still greenhouse gas emissions. Until recently hydro schemes were considered to have zero pollution while in operation, but some now consider the creation of water storage through the flooding of valleys and destruction of habitat as a form of pollution and greenhouse gas generation. Nevertheless, hydro power has saved New Zealand from being listed among the worst global greenhouse gas emitters per capita, but that country has now utilised practically all of the water resources available without introducing unacceptable environmental damage. In Tasmania some years ago the violent protests at the site of the proposed Franklin dam demonstrated that what might appear as magnificent opportunities for hydro-electricity production may be completely unacceptable because of the damage inflicted on the environment and local ecosystems. However there is a small scope for obtaining power from existing water storage dams such as the Warragamba dam near Sydney because a continuous discharge of water is necessary to maintain the health of the river system downstream from the dam. It has been seriously suggested that the Hunter Water Corporation could cut its annual four million dollar power bill by harnessing the water released to keep river flows fresh downstream from the Chichester dam, a major source of water for the Newcastle region. A mini power station should cost less than a million dollars and supply one hundred kilowatts (one tenth of a megawatt) of electricity, according to its advocates, because the Healthy Rivers Commission has recommended that the the daily release of water be increased seven-fold to 14 megalitres a day12. Provided it is designed to have a reversible turbine which can act as a pump, a hydro-electric installation has the great virtue of acting as an energy storage system. It can help to smooth out the typical daily peaks and troughs in the power consumption of consumers in the

12

Newcastle Herald, 2 October 1997

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serviced region. At times of low demand, excess power from base-load generating equipment, such as a nuclear power station, can be used to pump water up into the storage dam or reservoir. Then, in the late afternoon, when the domestic load is climbing and the industrial requirements are still high, the peak energy demand can be met by hydro-electric generation from the stored water. In southeast Australia the Tumut 3 hydroelectric power station with 1500 MWe capacity has a pumped storage capability (with an efficiency of around 70 percent) but the other six hydroelectric power stations of the Snowy Mountains scheme are suitable only for power generation. The total output of the seven stations is 3740 MWe but the lack of enough water severely curtails their operation. Even so, their contribution is extremely valuable for coping with peak power demands in New South Wales and Victoria. Other smaller hydroelectric installations produce up to 224 MWe of useful power. Pumped storage schemes like Tumut 3 require suitable reservoirs both above and below the station, which is not available at very many hydroelectric sites. In Argyll, Scotland, a huge reservoir and power station within Ben Cruachan together with the waters of Loch Awe at the foot of the mountain fill this function for the Scottish Power and Scotland Hydro-Electric supply authorities. Besides the obvious environmental damage due to drowned forests, habitat destruction and flooded farming country, dams, whether built for hydroelectricity or flood mitigation, have frequently failed, with losses of life numbered in the thousands. In this regard they are possibly the worst killers of all alternative energy sources. In the United States there are at least two hydroelectric dams whose sudden collapse would be an utter disaster costing over 200,000 lives. About once a decade at least there is a dam failure somewhere in the world with more than a thousand lives lost. Massive hydro installations cost lives even if they don't fail. During its construction the Snowy Mountains scheme cost over 120 lives. Cheap Electricity Capacity Factor Energy Payback Economy of area Greenhouse Gas OVERALL

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Wave Power

Harnessing wave power is still very much at the experimental stage. Theoretical and experimental studies are being carried out in Norway, Denmark and Scotland. Great Britain’s long coastline exposed as it is to heavy seas receives an enormous amount of wave power which almost constantly pounds its shores with a peak energy dissipation of up to 40 kW per metre of shoreline. An advantage of wave power is its greater availability when seas are running high in winter, the season when its electricity contribution is most needed. Obviously when seas are calm the output power will fall away quite drastically. Under moderate sea conditions it would be theoretically possible to equal the output of our standard one gigawatt power station by harnessing the energy delivered along 50 km of coastline. However that assumes complete energy extraction by perfect machines. In practice the conversion efficiencies are much lower, requiring machines operating over a greater extent of coast without any breaks.. There are two main classes of wave power machines: floaters and sitters. Floaters seem to be more efficient, but sitters are less susceptible to storm damage. For either class the working fluid may be oil or air, which drives a turbine or hydraulic motor, and of course the action is intermittent as the waves rise and fall. One type of floater that reportedly can extract up to ninety percent of the energy from waves is Salter’s `duck’, a large device which rocks like a see-saw with the wave action.. Another is Cockerell’s `raft’ design consisting of a line of rafts stretching out at right angles to the wavefront, with pistons between them. Both types have been under trial for many years and a full-scale installation using either of them has, to my knowledge, yet to be built. Experiments have been conducted in Denmark on a floater design consisting of a float like a buoy tethered to the sea-floor 30 metres below. The rise and fall of the waves drives a pump and generator producing one kilowatt of power from a two-metre wave height. Another type of sitter is the Vickers `duct’, a submerged tube which works rather like a coastal blowhole. In it the water rises and falls and compresses air to drive a turbine. It is perhaps the simplest and most robust of all.

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Each of these devices suffer to a greater or lesser extent the usual problems of all marine machines: corrosion, fouling and storm damage. Their environmental impact can be considerable and must be set against the amount of power generated. The fact that attempts to harness wave energy have been in train for decades without much success is not encouraging. Fifteen years ago an eight million dollar project was unveiled to build “the world’s biggest” wave power generator near Esperance in Western Australia13. The one-megawatt installation was to augment the wind-turbine farm nearby. The wind farm is delivering electricity but nothing more has been heard about the wave power contribution. However Energetech Australia, a private company, has presented a proposal to trial a new wave power system that uses a parabolic reflector to focus the energy in a 40-metre wavefront (AEN, No 7, 1998). The rush of water compresses air and drives a turbine producing “enough power for 2000 homes”14. That amounts to 2 MW, or 50 kW per metre, which is a trifle optimistic because it assumes continuous high seas. The company is seeking two million dollars to build a prototype which will generate electricity at about 15 cents a kWh. They maintain that their “unique system (which) does not use traditional ocean-hydro methods” will eventually produce electricity for less than 5 cents a kWh and that the coastline between Sydney and Newcastle is the best site. In view of the lack of success elsewhere in the world it will be interesting to see if this project gets anywhere, and, if started, doesn’t finish up as heaps of rusting equipment like shipwrecks dotted along the shoreline. In most countries nuclear power stations are bonded by law to fund full decommissioning at the end of their operating lifespan. Will the same provisions apply to other methods of power generation?

Tidal Power

At those coastal locations where the tidal range is sufficiently high a tidal power station may prove to be an economic proposition. Such an installation has been working successfully at the mouth of the River Rance, in France, since 1968. Others have since been built in Canada,

13

The Australian,May 2 1987. 14

Newcastle Herald, 26 June 1997

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China and Russia. The French installation extracts more than ninety percent of the energy of the water rushing into, then back out of, a large reservoir. When the tide turns and there is no head of water to drive the turbine there is no electrical output. Notwithstanding this unavoidable intermittency, the electricity generated amounts to 500 gigawatt-hours per year, roughly the equivalent of a 50 megawatt power station. A tidal power station is being considered for Broome, in the north of Western Australia, where the tidal range of eleven metres is the largest to be found anywhere around the Australian continent. Proponents believe that for a cost of a billion dollars hydro-turbines could be installed in dammed tidal estuaries along the Kimberley coastline to generate more than 250 GWe - ten times the nation’s current consumption15! To get the energy across to the East coast they propose to manufacture hydrogen and transfer it by pipeline in the same way natural gas is conveyed. This has the merit of overcoming the intermittency problem with tidal power. In conjunction with hydrogen fuel cells at the point where electricity is needed this proposal is one of the few with the potential to provide a reliable base-load electricity source. However it must be noted that piping huge quantities of highly inflammable hydrogen gas across a continent the size of Australia has never yet been attempted. By way of contrast, a recent proposal for a hydro-turbine16 in Newcastle harbour is a joke. The tidal range averages only one metre. For a flow turbine to operate effectively from the harbour ebb and flow a barrage would be necessary, seriously impeding shipping movements. If a separate tidal basin is constructed the size of a suburban swimming pool it might provide for about half the time an effective head of water of, say, one fifth of a metre which could be used to drive a small turbine. Assuming a basin capacity of 2 megalitres, the turbine could produce something like 200 watts of power while it is turning, barely enough to run a home computer. It would be a long time before the capital cost of the basin and turbo generator is returned, not to mention maintenance costs.

15

The Reader’s Digest Atlas of Australia, p47, 1994. 16

“Hunter’s Ark Plan Energy Showcase”, Newcastle Herald, 31 July 1997.

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OTEC Ocean Thermal Energy Conversion schemes have been bandied around for decades with nothing to show because the problems are enormous. The oceans are extremely efficient collectors of solar energy. Solar radiation penetrates the water and is trapped, maintaining in the tropics a surface temperature of around 25 degrees celsius night and day throughout the year. The Gulf stream carries warm water into temperate latitudes where it flows over much colder water, creating a thermal gradient of as much as twenty degrees. It is estimated that the thermal energy passing the coast of Florida is 10,000 times the total consumption of electricity in the United States. In 1929 a French engineer, Georges Claude, built and operated a 22 kW OTEC plant off the coast of Cuba17. Because OTEC schemes aim to draw upon the huge heat reservoirs in the world’s seas, making use of temperature gradients between upper and lower layers of water, they require sites where water deep enough is present close inshore. There are few suitable places in the world. The thermodynamic efficiency is woefully low, about five percent, requiring vast quantities of water to be passed through whatever system is employed. This and other problems like corrosion where seawater is involved (as with tidal or wave power) help explain why there are no OTEC plants anywhere.

Geothermal Power

Geothermal energy is derived from the natural heat below the earth's surface, which, on the human scale, would be virtually limitless if it could be accessed successfully. Wherever hot underground steam can be tapped and brought to the surface, either near volcanic regions or at sites where stronger than normal radioactive granites exist, it may be used to generate electricity. The engineering problems are immense due to the corrosive properties of dissolved minerals. Also the release of noxious gases can render it damaging to the environment. The countries where the engineering and economic problems have been overcome include California, Iceland, Italy, Japan, Mexico and

17

Cook, C S, “Renewable Energy: The Other Answer”, Yearbook of Science and the Future, Encyclopedia Britannica, 1979.

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New Zealand. A global total of some 6,500 MWe of capacity is in service, which equates to six or seven of our standard power stations. The Australian National University `Hotrock’ project18 is exploring Australia’s geothermal energy resources. The Cooper Basin in South Australia is considered to be the best site in the world because of the unusually high level of radioactivity in the underlying strata. Lesser reserves have been located by surface geophysical surveys in other geological basins, such as the heat reservoir considered to exist in granites four kilometres below the surface in the Hunter Valley of New South Wales, not far from the State's electricity grid. Although the Hunter Valley hotspot has an area of only fifty square kilometres, it is the second hottest (average temperature 250C) in Australia and holds enough energy to supply the entire continent for at least four years. The four-year estimate is due to the heat diminishing with time, because it is only slowly replenished by the rock's natural radioactivity. The Geodynamics company conducting test bores found that the hot-rock depth is a kilometer deeper than expected and have abandoned the Hunter Valley project in favour of the Cooper Basin. They plan a demonstration site costing $20 million to produce 13 MW of power at, they hope, just over 6 cents per kWh. There are some countries where geothermal steam is used directly for greenhouse heating, grain drying, water desalination and fish-farming, thus saving the need for that amount of electricity generation or the consumption of fuel. Large-scale use of geothermal heat is problematic. In most parts of the world the heat reaching the upper layers of the Earth’s crust is too weak for exploitation. Besides the regions mentioned earlier the only other places where appreciable geothermal heat is escaping are near mid-ocean ridges which are inaccessible and remote from population centres. So geothermal energy, being mostly low-grade and somewhat localised, is not a contender for supplying global electricity needs. Cheap Electricity Capacity Factor Energy Payback Economy of area Greenhouse Gas OVERALL

18

ANU Hotrock Project (http://hotrock.anu.edu.au, 2002).

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Nuclear Power

Because of relentless propaganda by various groups having an anti-nuclear agenda, abetted by a gullible media, there is a widespread belief that electricity generation employing nuclear fission reactors is unsafe. Not so. Unbiassed statistics show it to be one of the safest energy sources overall. No lives were lost through the major meltdown accident at Three Mile Island in 1979. And the 80 percent complete destruction of the number 4 reactor at Chernobyl in 1986 cost fewer than 50 lives, despite the widespread fallout and the subsequent clean-up operation (UNSCEAR 2000 Report). There are over 400 nuclear power reactors around the world, with up to eight at any single site. The majority of stations use highly reliable pressurised water reactors which draw their energy from enriched uranium fuel-rods. The extent of enrichment amounts to a few percent, a far cry from the more than ninety percent necessary for a nuclear bomb. All power reactors, including retro-fitted Soviet installations, have extensive safety systems. A member of the Presidential Commission investigating the TMI accident, A R Buhl, commented that had the operators simply walked away when the alarms began to sound the safety systems would have shut the reactor down successfully19 and it would not have suffered a financially disastrous melt-down. There are a number of new reactor designs that are inherently safe, needing no intervention if anything goes wrong - they simply slow down or stop functioning. Buhl also dispels the myth that operators were to blame for the TMI accident: it was their training that proved inadequate. The lessons have been learnt (as in the aviation industry) and these days, with comprehensive simulator training, reactor operators are, in their own sphere, as competent as airline captains. The Chernobyl disaster was another matter. There the operators violated several safety rules and because the Soviet RBMK reactors incorporated so few safety systems a disaster was almost inevitable. The operators simply did not know that RBMK reactors are unstable under certain low power regimes. About a month later their operating

19

Buhl, A R, Three Mile Island, NBS Special Publication 534, US Govt. Printing Office, Washington DC, pp 216-219, 1980.

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manuals were updated with that information, shamefully known all along to the nuclear power establishment in Moscow. Breeder reactors have suffered a bad press despite a good record of success. They are able to retrieve energy from depleted uranium and from the abundance of thorium in the earth's crust - enough to meet global energy demands for a millenium or more. India, for example, has an abundance of thorium reserves. They have successfully operated a small fast breeder test reactor and are about to start construction of a 500 Mwe prototype for future installations. For the foreseeable future nuclear fission reactors, including breeders, are the only environmentally benign source of energy to fully support the various forms of renewable energy and pave the way for an eventual transition to a hydrogen-based energy economy. Cheap Electricity Capacity Factor Energy Payback Economy of area Greenhouse Gas OVERALL

Nuclear Fusion For more than half a century major projects to obtain energy from the fusion of hydrogen to helium have yielded nothing more than a gradual climb towards the energy break-even point where, for a fraction of a second, the energy produced exceeds the energy fed in. It could be another century before continuous energy release is achieved to run a power station. The problems are so enormous, particularly in confining the millions-of-degrees process, that some doubt that it will ever succeed. Through neutron activation nuclear fusion is not free from the production of radioactive wastes, but this is less than the wastes from fission. So-called `table-top' fusion driven by a plasma discharge is a fun laboratory experiment but not a practical generator of useful energy. Cold fusion? This is the very long-odds outsider in the race for energy. If it can be made to work, a whole new chapter in the understanding of nuclear physics will be written. Although a number of groups are working on the problem it will greatly surprise the majority of nuclear physicists if they ever succeed.

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Global Primary Energy Mix and Kyoto

At the present time about 80 percent of the world’s energy is derived from the combustion of fossil fuels, with the remainder shared fairly equally between renewables (largely hydro) and nuclear. It is worth noting that the only countries with any hope of meeting the 2010 targets set by the Kyoto Protocol on greenhouse gas control are those generating nuclear power. Decades ago a Canadian expert on carbon emissions, Dr A A Bruneau, took into account the energy of construction of renewable energy sources and showed that if world energy demand was doubled by 2050 there would be little benefit in carbon dioxide reduction by raising the proportion of renewable energy beyond 20 percent at the expense of nuclear power generation at an assumed 65 percent20. It must also be remembered that all means of producing electrical energy present some degree of environmental degradation and are hazardous in one way or another. And it must not be overlooked that all energy sources generate wastes, even if only during the manufacture of the devices used. The nearest thing to `clean’ energy is what you receive when sunbaking and even that is carcinogenic!

There's a Place for Everything Just because some of the alternative energies have not scored many smileys does not imply that they should be disregarded. They each have a use somewhere in providing electrical energy. But there are few methods of generation capable of supplying the base load power vital for our economy. That is, until an efficient means of energy storage is ultimately developed. This includes the so-called 'hydrogen economy' which still has a lengthy development phase ahead before hydrogen becomes safe enough for widespread use. The main reason for writing this book is to counter the pie-in-the-sky promises of irresponsible alternative energy advocates. Nature is most unforgiving where energy is involved and cares not for political correctness or the wishful thinking of amateur scientists with `small is beautiful' social agendas.

20

A A Bruneau, National Science Council, Canada (see Wyatt 1978)

35

Many people, reading this far, will still consider nuclear electricity unpalable because of anti-nuclear propaganda suggesting all manner of problems. Even the most serious reactor disaster at Chernobyl, with a death toll of around fifty (see the UNSCEAR report), is eclipsed by many other energy-related disasters, mainly in the coal industry. Nuclear electricity is clean power. Its wastes can be readily contained and easily managed because they are so small for the amount of power generated. Effective disposal of nuclear waste is not a problem except to sadly misinformed citizens and green-blinkered politicians. A hard-hitting rebuttal of noisy anti-nuclear claims was written more than two decades ago by the late Sir Fred Hoyle and his son. It is a shame his revealing book has not been read and digested by media commentators hypnotised by the greens. It is also worth noting that the vast majority of Nobel laureates in the physical sciences, along with senior members of Australia's Academy of Sciences, support nuclear production of electricity. These people are not fools. The strongest supporters of nuclear electricity are those who know the most about it. So why are the real experts not listened to? Here in Australia we owe our descendants the opportunity to live in a properous society possible only through an abundance of energy to maintain a high standard of living for the greatly increased population that is forecast for the future. Nuclear electricity generation is the only proven technology able to meet this demand without unacceptable pollution. When the lights go out you can't say you weren't warned.

The Last Word - No Place for Bombs Early efforts to plan and construct Australia's first nuclear power station at Jervis Bay were clouded by demands for Australia to build nuclear weapons. Nuclear electricity and bombs are not necessarily linked. Of the 33 countries generating nuclear electricity, only a few have nuclear weapons. It's a purely political matter. From discussions with engineers and scientists of the former Australian Atomic Energy Commission I can report that they planned to construct a reactor purely for the generation of electricity. Had that station not been abandoned, this country could have been enjoying the benefits of clean, green nuclear electricity for the past quarter of a century.

36

Main reference sources AEN (Australian Energy News), published quarterly until June 2002 by the Department of Primary Industries and Energy, Canberra ACT. Beckmann, P, “Why `Soft’ Technology Will Not be America’s Energy Salvation”, Golem Press , Boulder CO, 1979. Campbell, C J, “Better Understanding Urged for Rapidly Depleting Reserves”, Oil and Gas Journal, April 7 1997. Cohen, B L, "The Nuclear Energy Option", Plenum Press, New York NY, 1990. ISBN 0-306-43567-5 Fleay, J F, “The Decline of the Age of Oil”. Pluto Press, Sydney N S W, 1995. Garwin, R L and G Charpak, "Megawatts and Megatons: A Turning Point in the Nuclear Age", A A Knopf, New York NY, 2001. ISBN 0-375-40394-9. Hayden, H C, "The Solar Fraud - Why Solar Energy Won' t Run the World", Vales Lake Publishing, Pueblo West CO, 2001, ISBN 0-9714845-0-3. Hoyle, F and G Hoyle, "Commonsense in Nuclear Energy", W H Freeman & Co, San Francisco CA, 1980, ISBN 0-7167-1237-7. Physics Today, Special issue :"The Energy Challenge", April 2002. Physics World, "Energy Challenges for the 21st Century", July 2002. Tsipenyuk, Yu M, “Nuclear Methods in Science and Technology”, Institute of Physics Publishing, Bristol 1997. ISBN 0-7503-0422-7 UNSCEAR 2000 Report, "Sources and effects of Ionising Radiation", United Nations Scientific Committee on the Effects of Atomic Radaition, Vol. 2, Annex J. ISBN 0-19-856540-2. Waltar, A E, "America the Powerless", Cogito Books, Madison WI, 1995. Every effort has been made to ensure the accuracy of the material presented in this booklet. If an error is detected the author would be pleased for it to be identified and be advised of a more authentic source. Should a correction be necessary, the author will be grateful and an amendment incorporated in future reprints.

Supplement 1

Nuclear Electricity Gigawatts Supplement 2005 Colin Keay

The Perils of Part-time Power

The only escape from the intermittency of solar or wind power is to have it

supported by reliable base-load generating capacity on hand with generators

fired up and spinning ready to carry the load whenever the wind drops below

about 4 m/s (14 km/hr), or when sunshine is absent. This requirement sets an

upper limit of around 20 percent for the amount of on-again, off-again green

power that can be absorbed within a national grid system. Even with good

weather forecasts, sudden variations in supply to the grid makes wind (and

solar) power a load manager’s nightmare.

This lesson is being learned the hard way by Denmark and Germany. Early

in 2004 Denmark was reported to have decided to build no more wind farms

on land or sea because wind-power has given them the most expensive

electricity in Europe. But they intend to continue manufacturing wind

turbines for export because of being world leaders in the technology.

Why is Danish power so dear? Because the wind is so fickle and the Danes

became too reliant on it. When, due to lack of wind, there is a shortage of.

electricity they have to import power at well above market prices. Often it

cannot be imported from neighboring Germany, where there is usually a

shortage of wind power at the same time. That leaves Denmark reliant on

power from the Nordic grid – where it is generated by hydro plant in

Norway, where over 95 percent is hydro power, or a mix of hydro and

nuclear power from Sweden.

On the other hand, when there are strong winds over much of northern

Europe there is a surplus of wind power. P Anderson of Eltra, one of the two

Danish Transmission Service Operators (grid controllers) claimed as early as

2001 that on occasions Denmark has had to give electricity away abroad for

nothing, or has even had to pay to get rid of its surplus! Eltra’s house

magazine quotes their chairman as stating that wind power has produced an

acute need for innovative thinking. The company has been forced to develop

a new plan to cope with the usual winter over-production of electricity.

Germany, with extensive wind farms all along its northern seaboard, has

run into similar difficulties. The 2003 paper “Challenges and Costs of

Integrating Growing Amounts of Wind Power Capacity into the Grid – Some

Experiences Dealing with 12,000 MW in Germany” by Steffin Sacharowitz

of the Berlin Technical University highlights the developing problems in that

country. The paper contains valuable material I have been seeking for a long

time, particularly a chart of the feed of wind power as a function of time over

Supplement 2

a period of twelve winter days for a major national grid system, in this

example Germany. Notice how the amount frequently falls away to next to

nothing – not good for industry and commerce,

The above chart gives the lie to green claims that variations in wind power

even out over an extensive region. The German wind farms, the most

extensive in the world, are prone to outages as much as smaller installations.

Supplement 3

As shown in the second graph, the capacity factor of wind farms varies

greatly with season, as one might well expect. However the maximum values

are the ones often quoted in brochures and publicity releases.

The effects of wind power on conventional power production can be quite

dramatic. It is found that a twenty percent wind power contribution results in

a net saving of only six or seven percent overall simply because base load

plant has to be kept on-line, at considerable expense, to absorb sudden wind

power shortfalls.

Germany is currently (2005) facing a showdown over power generation.

The German government’s energy research agency, supported by the wind

industry and supply companies, has produced a 490-page report proving that

their plans to double the current number of wind turbines by 2015 will result

in drastic cost rises to consumers who already heavily subsidise wind power.

Not only will their costs rise, from EUR 1.4 billion to EUR 5.4 billion, but

the government will need to invest EUR 1.1 billion in better grid

infrastructure to cope with supply fluctuations. The German Greens dispute

the report’s adverse findings and have forced its withdrawal for “re-editing”.

So, all told, wind power is not the greenhouse gas saviour that many hope.

And much the same will prove true for solar power. It is noteworthy that

Australia’s largest solar-cell array near Singleton, NSW, opened seven years

ago, has not been duplicated anywhere in Australia to my knowledge.

Do not imagine that here in this country we do not have subsidies for green

power like those operating in Denmark and Germany. Here we have MRET,

the Mandatory Renewable Energy Target scheme providing credits of up to

$A40 per megawatt-hour which halves the $A70 per MWh cost of wind

power, making it comparable to the $A30-35 per MWh cost of coal power

and $A40-42 per MWH cost of gas-fired power.

States in Australia facing serious power shortages in the near future are

WA, SA and Tasmania. The latter, like Norway, has a high fraction of hydro

power that can absorb fluctuations in supply if they build more wind farms.

South and Western Australia are not so fortunate, and their expansion of

wind power is restricted by their limited base-load capability. According to

energy consultant Dr Robert Booth, South Australia already has, like

Denmark, a dangerously high contribution from wind power. In future, in

both states, crippling blackouts seem likely at times of high demand.

Power blackouts are very costly to the economy. Industry and commerce

suffer severely when power fails. Losses will quickly mount up if the

construction of additional reliable base-load electric power plant is delayed.

Then Australia will really suffer the perils of part-time power.

Supplement 4

Wind Versus Nuclear Construction Costs

For a given delivery of electrical energy, the construction costs of a nuclear

power plant are much less than for an equivalent wind farm. This has been

vigorously contested by activists who claim that the construction of a nuclear

power station causes massive greenhouse gas emissions through the

manufacture of the required steel and concrete. It is a myth worth busting.

Let us look at the characteristics of a Danish Vestas V47-660 kilowatt wind

turbine similar to the one at Kooragang, in New South Wales.

The number of 660 kilowatt wind turbines needed to provide the same

energy output as a 1 gigawatt nuclear plant, assuming a generous 25 percent

capacity factor, is roughly 6,000. The amount of steel in the nacelle and 65

metre high tower is 93 tonnes (we won’t count a further 7 tonnes of other

materials, particularly in the massive rotor). The amount of concrete in the

massive base needed to anchor the structure in high winds ranges from 130

to 260 tonnes depending on the nature of the terrain. So for the 6000 wind

turbines we are considering, a total of more than half a million tonnes of

steel and around a million tonnes of concrete are required.

The size of wind turbine does not make much difference – the bigger the

turbine the fewer will be required. So the totals stay much the same..

Now look at nuclear power generation. The 1974 technical paper

“Estimated Quantities of Materials Contained in a 1,000 MWe PWR Power

Plant” by R Bryan and I Dudley of the Oak Ridge National Laboratory

presented the following figures (for a Pressurised Water Reactor plant

including the turbo-alternators and connection to the grid): 35,000 tonnes of

steel and 200,000 tonnes of concrete.

Thus we find that the wind farm producing as much energy as a nuclear

power station requires around fourteen times as much steel and five times as

much concrete. It is inescapable that constructing a wind farm is much more

demanding on materials – and hence greenhouse gas contribution from their

manufacture – than a nuclear installation of equal output. And this difference

will to a large degree be reflected in their overall costs.

* * *

This supplement shows how thorough investigation is essential to refute

only two of the many unsupportable claims made by irresponsible elements

of those opposed to safe, clean nuclear electricity production. See the book

“Nuclear Energy Fallacies” in my Nuclear Issues series for many examples.

Inside back cover

Have you seen the first booklet "Nuclear Energy Fallacies -

Forty Reasons to Stop and Think" in this series designed to

make average Australians better informed on important

nuclear issues?

Here is what an eminent Australian scientist and a leading

newspaper columnist had to say about it…

"Too often debates on important issues get tied up

with political correctness and unjustified declarations.

I welcome this contribution by Dr Keay to the nuclear

debate. In his booklet he has provided guidance on

valuable source material which ensures that facts

rather than hysterics drive the discussion."

Professor John O'Connor, President, Australian

Institute of Physics

"Keay lists (anti-nuclear) myth after myth and neatly

disposes of them all…"

Padraic McGuiness, Sydney Morning Herald

This booklet was mentioned in the NSW Hansard on

November 29, 2001, and gained international exposure on

the ABC Ockham's Razor program on February 17, 2002.

Back cover

"Nuclear Radiation Exposed - A Guide to Better

Understanding", the second booklet in this series has been

written to calm public alarm about nuclear radiation. Here

is the response from a recognised Australian expert on

environmental biology, Emeritus Professor Peter Parsons

from LaTrobe University, to whom a copy was sent…

"Thanks very much for the book on Nuclear

Radiation Exposed, which excellently crosses the

many disciplines required for an understanding of the

biological effects of ionising radiation. It should help

to expose some of the hysteria associated with the

'Nuclear Debate'….".

Peter Parsons.

The four booklets of this Nuclear Issues series are no longer on sale. They are now accessible on line in the form of four PDF files that may be copied in full without change or in part subject to normal copyright law.

ISBN 0-9578946-2-7