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Going electric with the ‘Energy Tower’

Posted By Deborah Frenkel On December 7, 2007 @ 4:15 pm In | No Comments

Professor Dan Zaslavsky: We could easily produce between 15 to 20 times the total electricity the world uses today.

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.”

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