The Australian mass media seems to have undergone something of a sea change in recent times. Not so long ago, environmental stories would have been consigned to a few column centimetres on page 14, or a 30-second visual byte on TV. Suddenly, and particularly over the past 6 months, such stories are making headlines almost weekly.
Over this short period we have had lengthy, often front-page reports on plans to build new nuclear power stations, solar power stations, targets for increased ethanol content in our petrol, government-backed infomercials outlining schemes to secure our water supplies, and even intrepid television reporters jumping onto icebergs off the New Zealand coast.
What has inspired this flurry of activity? Why is the environment suddenly commanding so much attention? Cynics might argue that, with the worst drought on record, a squeeze on electricity supply, and the impetus of federal and state elections, environmental management has at last become a vote winner – or loser. It has, although the true catalyst is no further away than your nearest petrol bowser. Recent hikes in fuel prices have led to higher transportation costs, which, in turn, have impacted negatively on the cost of consumer goods, and this is bad news for politicians, because it raises the spectre of that dirtiest of all words (in politics): inflation.
However, the fuel crisis has also prismatically focused attention on the wider environmental picture, and this both sides of politics have jumped on an environmental bandwagon, in order to promote their alternative energy agendas. It may be grandstanding; it may be out of self-interest, but we should be grateful that alternatives to fossil fuel are now receiving the attention they deserve.
Unfortunately, every one of those alternatives comes with a price tag, and if we are to believe (as I do) that any future energy policy should espouse the judicious use of anything up to a dozen different power sources, then we should examine the pros and cons of each.
We all know that if environmentalists could circulate ‘wanted’ posters, then public enemy number one would be fossil fuel emissions. The burning of fossil fuels is the greatest single contributor to global warming, and much of our current predicament is due to the fact that these are still our most abundant energy sources. Oil supplies may be dwindling, but a complete dry-up is still a long way off, and we have enough coal to last several centuries. It follows that we have to live with the fact that coal-fired power stations and – to a lesser degree – petrol engines, will be with us for some time to come, while any increase in cleaner energies will have to be phased in. It is in our interest to fast track the process, but it will still be gradual.
During this transition period it therefore makes sense to clean up the existing technologies as best we can, especially with respect to coal-fired power plants. And this is achievable. So-called ‘clean coal’ stations can work, and it has only been penny-pinching that has prevented their development up until now. Several methods exist whereby the emissions from these stations can be converted to harmless gases. One utilises waste heat, collecting it as hot water which can be piped to nearby towns to supply winter heating. Another converts coal to hydrogen which is burnt in a gas turbine, leaving behind only water vapour. A third, invented in Norway, actually sequesters the carbon dioxide from the power station and buries it in a disused natural gas field under the seabed. All of these would add to domestic and industrial electricity costs, but only incrementally. The price hike would be affordable, even to ‘ordinary battlers’.
Of all the alternatives to fossil fuels, the one which has received the most publicity is nuclear energy. In earlier columns for this magazine I have made my position on this perfectly clear. I am in the anti camp. It is not issues such as the possibility of a Chernobyl-type incident which concern me the most. The atmospheric radiation from such an event dissipates quite rapidly in the upper atmosphere, and recent studies have shown (to the surprise, and even dismay of scientists, who were trying to prove the opposite) that our tolerance to radioactivity is much higher than was earlier suspected. The workers who went in and sealed the Chernobyl leak, paid for their bravery with their lives, but those workers apart, it appears that the infamous radioactive cloud has had little or no impact on the health of anyone else, near to or far from, Chernobyl.
Furthermore, as events such as Chernobyl are extremely rare, nuclear power does present itself as an attractive proposition, as it is clean, and contributes nothing to atmospheric pollution, and therefore to global warming. Even the eminent British scientist, and founder of Gaia theory, James Lovelock, has recently espoused the nuclear option. In The Revenge of Gaia, published last year, he waxes lyrical about nuclear energy, although he does stress that it should be viewed as only a short-term solution, because no one has yet solved the problem of what to do with radioactive nuclear waste.
It is the disposal of that waste, and the possibility of radioactive leaks into underground water supplies, that is at the core of my own opposition to nuclear power. Also, with respect to Dr Lovelock, he does exhibit something of a ‘gamekeeper turned poacher’ attitude in his book, especially when he points out that natural gas pipelines, with their tendency to leak, present a very soft target to potential terrorists. He does not say the same of nuclear power stations, but I believe that these are even more attractive to the fanatical few, especially if (as seems likely) any new plants are going to be built in heavily urbanised coastal areas. A radioactive leak from a power station is not a Hiroshima or Nagasaki, but a terrorist attack on such a building would turn it into one. With apologies to Lovelock – whom I greatly admire – it is still a thumbs down to nuclear, at least from my point of view.
The power stations just discussed are, of course, producing electricity by means of nuclear fission, or the splitting of atoms. There is an alternative to this, nuclear fusion, or the conjoining of atoms. This is totally safe, has no emissions, radioactive or otherwise. Unfortunately, it is also completely impractical, as it requires almost unbelievably hot temperatures in order to work. We are talking in the order of 150 billion degrees, hotter than the core of the sun, which fuels itself by just such fusion.
Experimentally, these temperatures have been achieved, but only for a couple of seconds or so, and while the energy output was an impressive 16 megawatts, the prototype reactor used more than that amount in order to kick-start the reaction. Put simply, nuclear fusion, in its present form, cannot be implemented, as the very generation process itself would use up all the available combustible fuel on earth. The holy grail of thermo-nuclear scientists is the perfection of what is called ‘cold temperature fusion’, but the technology here has stalled, and we seem no closer to that perfect solution (and without doubt it is a perfect solution) than we were when it was first mooted over 40 years ago.
Hydro and geothermal energy
Hydroelectricity is often touted as clean and green. Clean it is, green not. Any damming of a river system, be it for hydro power or water storage, inherently alters the environmental balance of the region affected, and this region can extend across hundreds, even thousands of square kilometres. When Tasmania’s Lake Pedder was dammed in the 1970s, Australia lost something unique: an inland beach. The Snowy Hydro scheme similarly compromised what was once one of our fastest flowing rivers. Downstream of the hydro plants, the Snowy, immortalised in verse and on celluloid, is no more than trickle, which can no longer support the variety of aquatic life that it harboured before the power plants were built.
A more exciting energy source, and one which is 60 times larger than the Snowy scheme, is the recently discovered geothermal reserve in the Cooper Basin, straddling the South Australian and Queensland borders. Geothermal, or ‘hot rock’ technology is usually fraught with extraction problems, either because it is inaccessible, being located under the sea (as in the Hawaiian geothermal vents), or because it is in a ‘no go’ area, being located in a protected national park, such as the Geyser National monument (including ‘Old Faithful’) in Wyoming’s Yellowstone Park.
No one would seriously consider putting a power plant in Yellowstone, or, for that matter, on top of the bubbling mud at Rotorua in New Zealand (although geothermal energy from other, less touristy locations nearby, is utilised). However, when a subterranean source can be accessed, as in the Cooper Basin, the electricity extraction/generation process is little different from standard technologies as presently practised in coal-fired power stations, except that it is – happily – emission free. Geothermal is certainly an option to be developed, and current projections indicate that ‘hot rock’ technology could inject up to $10 billion into our economy over the next 25 years, and that our geothermal resources, nationwide, could be the equivalent of 450 years’ worth of electricity consumption at present-day levels. It is gratifying to see that this clean energy source is already the subject of exploratory drilling, which will turn into a viable operation over the next few years, and one which could generate 10 percent of our electricity supply in the short term, and doubtless much more as the technology is refined and further sources discovered.
Geothermal may be an exciting new development, but excitement is beginning to wane with respect to a technology that has now been with us for quite some time: wind power. When the first, experimental, wind farms were built, everyone enthused about this new energy source, precisely because it was seen as another clean, green alternative to coal. And it is true that wind farms give off next to nothing in terms of pollutants. The problem is that they are extremely inefficient. Below a certain wind speed (about 15 km/h) the turbines will not operate, and there is also an upper limit (approaching 60 km/h) at which they cut off for safety and other reasons. The optimum operational wind velocity is in the 20-30 km/h range, and this automatically means that electricity is generated only intermittently, 25% of the time at best. This is also why some environmentalists believe that wind farms are best located some distance offshore, in the middle of the sea, but this creates logistic problems of both delivery of the supply and maintenance of the turbines.
The best location for wind turbines is some distance inland, on low hills. Here they can function at optimum capacity, and make a real contribution to the electricity grid. The wind farms near Livingston in California, and Blayney in New South Wales are excellent examples. Unfortunately, some wind farm companies insist on building forests of turbines in coastal locations and this creates considerable angst as regards aesthetics, for the turbines are rather noisy, and extremely unsightly. Furthermore, because each individual turbine has a very limited carrying capacity, to make wind farms a major alternative to fossil fuels would require the building of so many that the entire land surface of some countries would be dotted with them. It has been estimated, for example, that if Britain were to be fully wind powered, the island would have to have some 276,000 turbines, or two for each and every square kilometre.
I believe that a more attractive proposition, and one that has not received nearly so much attention as wind, is wave, or tidal energy. To begin with, it is more reliable than wind, for although tidal strengths vary, tides are never absent. It is possible to have lengthy periods without an appreciable wind, but tides are in constant motion, and can therefore generate electricity uninterrupted. The only mitigating factor in this would be occasional and severe increases in tidal strengths, which would force the generators to shut down. This would occur at times of severe storm, or even cyclone activity, and with increased global warming these episodes will become more frequent. However, it is unlikely that that frequency would increase to a point where tides became totally unpredictable. I think it would be safe to estimate that wave-powered turbines could be functional for at least 95 percent of the time, even if – as predicted – ocean levels were to rise by a metre or so.
The other advantage of tidal energy is that we already have operational models to work with, and this takes out much of the guesswork. At La Rance, near Cherbourg, a tidal station has been supplementing France’s predominantly nuclear energy for many years, and a British proposal to build a tidal barrage across the River Severn estuary, though costly (13 billion pounds), is economically feasible, as it would deliver some six percent of Britain’s electricity needs, and, unlike a dam, a barrage would not have much negative impact on the overall estuarine ecology.
More to come
Of course, all of the alternative energy above are centred on the generation of electricity to provide power, light and heat. Thus far I have not touched on the alternative that appeals to me most, solar energy, or on any alternative sources of locomotion, which is our other great energy consumer. Solar power, plus transitions from, and replacements for, petrol engines will be discussed in next month’s issue, at which time I shall also attempt to come up with a formula to determine what energy sources should be used, in which proportions, in both the short and long term.
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