Energy Tower Visionary: How It Works [INTERVIEW]

Imagine a power plant that used only cold air to spin a turbine: no need for expensive solar PV panels or gigantic wind turbines.

The theory is simple, says Dan Zaslavsky, a professor of agricultural engineering at the Technion, Israel’s Intitute of Technology. The mastermind behind the Energy Tower, Zaslavsky says the technology uses a principle that’s been known for hundreds of years: “If you spray water into the air, the air cools. Cool air is heavier than hot air, and it drops down,” he told EarthTechling in a phone interview.

image via Dan Zaslavsky

The abundance of hot dry air in Israel’s desert climate, makes the damp cold air drop to the bottom of the tower very effectively. There its spins a turbine that is connected to a generator, creating electricity from nothing but cool air, 24 hours a day, seven days a week. According to Vi, who designed the Energy Tower that can do just this, the technology can supply electricity at the lowest known cost (2.5-3.5 cents per  kilowatt-hour), on a relatively small plot of land and in the widest range of climate conditions.

With a severe scarcity of water in Israel, Zaslavsky realized quickly he would have to find a a good way to use the water for the tower as efficiently as possible. And that led his team to a perhaps even greater discovery: The tower would also work with ocean water, and as the ocean water goes through the tower, it actually self-desalinates so that there is a freshwater byproduct.

Israel is already pouring millions of dollars into desalination plants because it is quickly depleting its freshwater resources. But the Energy Tower can produce freshwater more cheaply than a traditional desalination plant, according to Zaslavsky, all the while producing many megawatts of renewable energy.

Zaslavsky has also toyed with the idea of setting up fisheries next to the Energy Towers. Raising fish could compensate for the cost on transporting thousands of gallons of ocean water into the desert and could fill a much needed gap in supply of shore-side fishery real estate.

The idea is so revolutionary that UNESCO has asked Zaslavsky to write a full report on his research, which includes various other Israel-based renewable energy visions, with the hope that renewable energy supplies in the region can be multiplied in the coming years.

But while Zaslavsky may have been among the first to think of the idea, other companies are commercializing similar technologies. In October 2011, EarthTechling reported on a downdraft wind tower currenrly being developed by Marlyand company Clean Wind Energy. Calling it the “Downdraft Tower,” Clean Wind Energy also thought of locating it technology in the desert, but in the American Southwest. In late April, the company said it would finally be proceeding with plans to construct two of their enormous 3,000-feet tall towers in the Arizona desert as part of an innovative new wind power, although there was no indication of where the financing for the project might come from.

Shifra Mincer is a freelance journalist and passionate tweeter (@Shiframincer) currently living in Israel. Before moving to Israel to apprentice with a homebirth midwife, Shifra worked as Associate Editor of AOL Energy, and was a member of the launch team that got the site up and running. Shifra has over a half a decade of experience in journalism and has written on women's health, green technology, politics and regulation of the energy industry, energy financial news, and local news. While studying for her B.A. at Harvard College, Shifra worked as a news editor for the Harvard Crimson. Shifra is also a yoga teacher and a birth doula and is hoping to create an active Jewish birth community through her web venture www.layda.org.