I like taking advantage of convection. Ax the Wiz...he knows.
This is so cool. My son told me about this. Bounced some ideas off each other, re connected with a coal plant for sequestration, use it for growing algae for biofuels, ...
A Tower in Oz to Touch the Sun
Daithà Ó hAnluain 09.06.02 | 2:00 AM
Last week the Australian government added its support, but no cash, to a hugely ambitious renewable energy project: the 1 kilometer-high solar tower.
The project is a solar-generated wind farm on a massive scale. It works on the principle of convection -- hot air rises -- and the tower functions like a chimney.
In a big chimney, air can rise very quickly. The air reaches 65 degrees Celsius at a speed of 35 mph toward the center of the 7-kilometer collector -- essentially a big greenhouse. As it rises, it turns specially designed wind turbines and produces electricity.
When night falls, heat stored in solar cells during the day is released and continues to turn the turbines. Unlike traditional wind farms, the tower doesn't have to rely on the weather for a good crop. It produces its own wind, 24 hours a day.
The project resembles a modern tower of Babel, and it's almost as ambitious. It will be nearly double the height of the world's tallest structure, the CN Tower in Canada. It will be visible from space as well as 80 miles away at ground level.
If it is built.
Its chief promoter, EnviroMission, is very serious about the plan, and the company has some very serious people who say they can do it.
For starters, the Australian federal government recently awarded the tower Major Project Facilitation Status.
It means the project is of major public interest, has the moral backing of the Australian government and will be fast-tracked by government agencies.
The government couldn't wait to get in on the act.
"This project confirms Australia as a world leader in renewable energy production aimed at reducing greenhouse gases. The EnviroMission venture will represent the world's first full-scale application of this new solar technology," said Ian Macfarlane, Australia's federal minister of Industry, Tourism and Resources.
The project's credibility is enhanced by the technology's developers, German structural engineers Schlaich Bergermann and Partner (SBP), one of the world's most prestigious design companies.
SBP has previously experimented with other alternative energy sources, notably a solar power-collecting dish that can reach temperatures of 700 degrees.
"We developed the solar tower prototype in Spain after the oil crises of the early '80s," says Wolfgang Schiel. "But we didn't get a chance to develop the system because everybody thought oil would go up to $36 a barrel and actually it dropped to $15 and everybody lost interest."
Until now. The prospect of climate change and the demand for carbon emissions control has given new impetus and financial feasibility to the
It's also impressed environmental activists abroad. "Such a plant may be relatively costly to build compared with a conventional wind farm," said Robin Harper of the Green Party in Scotland. "But its advantage is that it can run when there is no wind and also at night.
"This gets around the problem of having to store energy, one of the biggest criticisms of most existing wind and solar technologies."
A 1-kilometer tower can produce 200 megawatts, enough electricity to power 200,000 homes. This energy output will represent an annual savings of 830,000 tons of greenhouse CO2 gases from entering the atmosphere.
"One of these plants would produce as much electricity as a small nuclear reactor, so they are a very serious proposition," Harper said.
The tower would also have a huge tourism impact. In fact, the majority of the 50 jobs projected for the power plant would be in the visitor center. It takes just 15 staff members to run the station.
Wentworth Shire, New South Wales -- the town where the solar tower will be located -- certainly sees its potential.
"The significance of this project cannot be overstated," says Wentworth mayor Don McKinnon.
The company says it hopes to begin construction early in 2003 and open the plant by late 2005 or early 2006.
wired.com
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Going electric with the 'Energy Tower'
By Deborah Frenkel December 07, 2007
Professor Dan Zaslavsky: We could easily produce between 15 to 20 times the total electricity the world uses today.
Energy Tower
The Israeli inventors call it an Energy Tower, and if it's adopted worldwide it could become a major source of cheap electricity.
So what is it? Project founder, Professor Dan Zaslavsky of the Department of Agricultural Engineering at the Technion - Israel Institute of Science, explains. It's a tall tower, 1, 000 yards in height and 400 yardsin diameter, located somewhere hot and dry with a source of water at the ready nearby - either the sea, brackish estuarine, or drainage water.
The water is used to cool the air at the top of the tower. The heavier cooled air sinks downwards, gathers speed as it falls, finally powering turbines at the tower's base. Put simply, it's the principle of convection - warm air rises above cool air - a law so fundamental that it is taught in elementary schools.
"It's a radically simple idea," Zaslavsky told ISRAEL21c. "We could easily produce between 15 to 20 times the total electricity the world uses today."
Renewable energy is one of the hottest areas of growth these days. With global warming accelerating and fossil fuels expected to run out in decades, the hunt is on for alternative energy sources.
The Technion researchers began work on the Energy Tower in 1983 and since then more than 150 man-years have been spent on its development by professors, engineers, PhD students and even the Israel Electric Corporation.
They all agree that the project is sound in every respect except one - the lack of a major investor. "We need funds," says Zaslavsky. "The development stage is over; the work is viable. But there are a lot of obstacles to getting it off the ground."
Ironically, one of these obstacles has proven to be the very condition that has allowed the research to flourish - a burgeoning global interest in alternative energy sources. It's a crowded market now, Zaslavsky points out, and with so much politically and economically at stake, "everyone has his own baby."
This baby, though, aims higher than its competitors, and not just in a literal sense. According to Zaslavsky, the basic tower design could be easily modified to incorporate facilities enabling desalination, producing fresh water reserves at only half the cost of existing desalination technologies. Such reserves could then be used nearby for the production of bio-fuels such as sugar, for example, or used in fish farming, a remarkably energy-efficient form of agriculture.
"We can produce cheap desalinated water, we can irrigate the desert, we can produce bio-fuel, we can boost aquaculture," Zaslavsky recites.
His team estimates the running costs of the electricity for this project at 2.5 cents per kilowatt-hour, less than a third of the cost of electricity in Israel today, and far cheaper than any mooted alternative such as solar, hydro-electric or wind power.
Such promise might be enough to convince anyone of the technology's merits. But Zaslavsky isn't done yet. The team has calculated that the towers may actually be able to reverse the mechanism of global warming.
"There is a natural process by which the earth cools itself known as Hadley Cell Circulation. This naturally happens mostly over the equator, where air is already humid," he told ISRAEL21c. "But if we find a way to humidify desert air, this global cooling process can occur over desert latitudes too. And the energy towers work by doing exactly that."
It's a compelling scenario. But none of these benefits will ensue, of course, unless the towers actually get built. And while the team has already identified regions in about 40 countries where towers could be viable - in the Middle East, Australia, North Africa, California and Mexico, for example - construction remains a far-off dream.
"This technology is so fascinating and exciting," Zaslavsky enthuses. And indeed, the benefits the energy tower promises - a cheap, 24/7, eternally renewable source of power, combined with desalinated water, desert agriculture, plus some progress towards healing our planet's wounds - are undeniably huge.
But will that be enough to launch the project? Interest has come from a number of investors in the United States, the former USSR and elsewhere in the Middle East - but as yet, no deals are concluded.
So is there a real chance our future will be one of tower-power? "Oh, yes; in 25 years we could take over the world," he laughs. "But all we need is a chance today."
israel21c.org. |
