HAIFA, Israel — In biblical times, energy seemed to perpetuate itself. Witness the never-extinguishing burning bush or the Chanukah oil that lasted eight days.

The same can't be said in our high-voltage, consumer-driven times. But in Israel, the site of those biblical miracles, scientists are developing new ways to renew energy and to solve some of the world's most pressing environmental problems.

Projects range in scale from a gigantic source of renewable energy to a tiny disk that monitors sun exposure. Their potential to tackle environmental challenges reflects a can-do attitude that's quintessentially Israeli.

If Professor Dan Zaslavsky has his way, much of the world's future power will be drawn from one of its most plentiful elements — sea water — in an immense tower that would dominate the desert landscape.

Zaslavsky, professor of agricultural engineering at Haifa's Technion-Israel Institute of Technology, has been working for years to develop a source of clean, reliable and cheap energy.

Currently, he has pinned all his hopes on an energy tower that, if built, would measure at least 3,000 feet — more than twice the height of New York's World Trade Center towers.

The tower might be immense but it embodies a simple principle. Essentially, it would act as a vertical wind tunnel to transform sea water into energy.

"Water sprayed into the top of the tower evaporates and cools the air around it," Zaslavsky said. That cool air, heavier than the desert air around it, then sinks rapidly and creates wind that can be used to power turbines.

At 2.5 to 5.5 cents per kilowatt, the energy produced by the tower would be cheap — and unlike solar panels, the structure would be active around the clock, obviating the need to collect it.

"What kills solar energy is the problem of collecting it," says Zaslavsky. "My feeling was that we had to get rid of that need."

The project has generated excitement in the Israeli government, but Zaslavsky has yet to raise the $65 million needed to build a demonstration tower.

It's a big vision, but the scientist says the potential gains are huge. "One tower could meet the energy needs of a city of one million people; 40 countries in the world with desert regions could benefit from the towers."

At the opposite end of the scale are Ori Faran's tiny Skyrad patches, which enable individuals to measure sun exposure at a cost of mere pennies.

Faran is one of several dozen scientists working at the Technion Entrepreneurial Incubator Co., set up in 1991 to provide scientific entrepreneurs with financial support and R&D facilities.

He first got the idea for the patch when, as a developer of cancer detection instruments, he was tested daily for exposure to radioactive materials in his work environment. He was inspired to develop a personal disposable ultraviolet dosimeter to measure the amount of radiation absorbed.

"For each one percent increase in the ozone hole, there's a four to five per cent increase in skin cancer," Faran says. "The problem is that people don't have any means to know when to get out of the sun."

With Faran's product, such ignorance could soon be a thing of the past.

The self-adhesive patch, or disk, changes color when its wearer is in danger of burning in the sun. Disks can be attached to clothing or accessories, and are calibrated for five different skin types.

"The amount of radiation that causes skin cancer is unknown," says Faran. "But if you never reach the level of sunburn, your chances of not developing skin cancer are much better."

Since they'll cost only 20 cents each, you don't even have to be a sun-worshipper to get excited about the patches, which was launched in Australia in December and will be introduced in the United States this summer.

Faran even envisages a time when the patches will be incorporated into garments in the form of patterns or logos — meaning that your T-shirt could soon be telling you when to get out of the sun.

While Faran's patches will be good for gardeners, a new biodegradable polymer created at TEIC will be good for the garden itself.

The polymer is being developed by Giora Herman's start-up company Rademate, whose research — like that of Faran — has been nurtured in the Technion incubator.

With world garbage levels spiraling out of control, the need for biodegradable materials is irrefutable.

"There are more than two billion tons of plastic garbage in the world," Herman says.

Several biodegradable plastics are currently available, but at $10 to $22 per pound they can't compete with conventional plastic, which typically costs around $2.20 per pound.

Rademate has developed a polymer that "will be much cheaper," at $2.20 to $10 per pound, Herman says.

Unlike existing products, the product isn't plastic-based. Instead, chief scientist Michael Ioelivich developed a cellulose-based material that could mimic the properties of plastic.

So far, Rademate has used the cellulose-based polymer to coat paper and cardboard objects, including plant pots used for seedlings.

If all goes well, the company also hopes to address a not-so-sweet-smelling environmental problem — the global scourge of plastic diapers.

"You can't burn them, you can't shred them," says Herman. "They're the biggest waste problem today in the U.S."

Where there's plastic waste, there are also contaminants. Enter Professor Israel Schechter, who's developing a variety of detection systems for environmental analysis.

Schechter, a faculty member in the Technion's chemistry department, is working on systems that will monitor contaminant levels everywhere — from the site of Israel's precious groundwater to the skins of supermarket produce.

The problem with most current methods of testing, he says, is that they take place away from the field. "They're slow, time-consuming and expensive."

His devices would change all that. Employing lasers, fluorescent light and chemical imaging, they're designed to be used onsite and to give instant results.

One device, which analyzes carcinogens in aerosols, is being marketed by the Tel Aviv company Green Vision and is in use in several U.S. states.

Another product monitors chemicals in the country's groundwater — an urgent concern in Israel.

Like the other environmentally minded scientists, Schechter is motivated by a vision of a greener future — and he's marshaling every available brain cell to make the vision a reality.

"I want to know the quality of the air I breathe, the water I drink, and the fruit I eat," he says.

"If other people care about these things, there's a market for these devices."