In reply to Wesley Bruce's message of Sat, 20 May 2006 17:28:08 +1000: Hi, [snip] >The problem that needs to be dealt with is not cheep generation of >energy. We have that in spades,
Not quite true. Wind is still slightly more expensive than coal or gas, Solar thermal more expensive than wind. Photovoltaic considerably more expensive. Solar thermal is more expensive primarily because people insist on using heavy metal structures to support the mirrors. The system I described would only use rigid light plastic supports for the lenses, and these could be turned out in massive quantities at very low cost. >wave power could power the planet twice >over, wind could power half the world. Roof top solar could power the >average city if solar cells replaced tiles on the sunward side of the roof. Yes, but expensively. >We don't have a shortage of energy technologies we have a delivery >problem. We have both. Believe you me, if Solar were cheaper than coal or gas, there would no holding the utilities back. :) [snip] > The great irony is that we have had a solution to both large scale >shipping and storage of energy since the 1800's its *compressed air*. >Modern studies have not been made but a compressed air line across >Australia would be possible. Compressors are over 90% efficient. Does this imply isothermal expansion such that heat lost to the environment during compression is reabsorbed during expansion? >2 meter >diameter steel lined concrete Pipes can be made largely leak free. >Workable pressures would be 50 atmospheres. A gale in a pile. Pipelines >under the sea are not impossible particularly if your crossing shallow >seas [ The Arafura and Banda sea are not that deep. The sea bed from >Bali to Malaysia is only a few tens of meters deep and in places a path >only 50 meters deep can be mapped.] You must ballast the pipe properly. > Yes pneumatic systems have frictional losses but at a few percent >per hundred kilometres its better than the losses in high voltage and >superconductors. Its also a storage system. The air in the line goes in >by day and may be drawn out at night with only a small drop in pressure. ...agreed, the more so the longer the pipe. >Large volumes of air can be diverted into former gas baring strata and >just as the gas was retained in the past at several atmospheres the air >will be today. One power storage plant using compressed air pushed down >an old gas well already exists and is commercial. > For some strange reason the world has chosen to ignore the >relatively simple physics of pneumatic solutions in favour of other more >exotic and expensive system that may promise solutions on some distant >day. Underground storage solutions are not available everywhere. A more generally applicable solution might be chemical storage. Even hydrocarbon manufacture from airborne CO2 is not out of the question, if a sufficiently cheap, but intermittent, source of power is available. In fact it might be possible to combine it with your compressed air system. Once compressed, the air could be passed through Ca(OH)2 before entering the pipe. This would scrub any CO2 from the air producing CaCO3, which can then be heated (solar thermal) to remove the CO2 in pure form and pass it to the chemical plant where it is converted to more useful chemicals using once again power from the Solar plant. Regards, Robin van Spaandonk http://users.bigpond.net.au/rvanspaa/ Competition provides the motivation, Cooperation provides the means.
