Smokestacks to the Sky
A long-shelved solar scheme has been reactivated by a Sri Lankan company that has a bright idea to generate energy from the sun and make the deserts bloom
By Ron Gluckman / Colombo
DAYA SENANAYAKE IS AN UNUSUAL DEVELOPER. Instead of waterfront property or views, desolation is his desire. On a day hot and dry enough to burn the ends of his graying beard, Daya Senanayake dreams only of turning up the heat.
Desert is scarce in Sri Lanka, but Senanayake has scoured the island to find a perfect plot of parched land. Thinking of a wide, flat stretch of earth in the northwestern part of the country, Senanayake smiles. Bulbs light in his brain as he pictures the barren plain. He imagines greenery, prosperity and something more: unlimited energy. "A small area of the Sahara Desert could produce all the world's power," says Senanayake. "It's possible. And not sometime. Now."
Senanayake dreams one of the greatest of dreams: to harness the sun's rays. In the process, he would bring not only electricity but also water to the world's arid wastelands, turning them green and productive.
The terrible cycles of famine would end in Africa. And, best of all, the energy fueling Senanayake's remarkable plan would be completely clean.
Capturing the power of the sun has been an aim of scientists and philosophers for centuries. So it would be easy to dismiss Senanayake as just another idealist. Many have. Drawings of the "solar chimney" that Senanayake and his associate, Viren de Mel, have been touting around Asia go back more than a decade. The illustrations depict towering concrete chimneys, hundreds of meters high, sprouting in wilderness and surrounded by thousands of hectares of shiny glass. "The concept is really quite simple," de Mel explains. "Air is heated under the glass by the sun, and moves through the chimney, turning a turbine, generating power."
Though the concept may be simple, the scale is astounding. A viable commercial plant could require a chimney 600 to 950 meters tall -- the tallest on Earth-- and an enclosure covering 10,000 hectares in glass. With ample irrigation, crops would flourish under the glass. "There's big, big potential here," de Mel adds. "One small plant could create 1,500 jobs in greenhouse agriculture. The possibilities are enormous."
Senanayake is a proven innovator with 13 patents to his credit. He's also deputy chairman of the Colombo-based Ceylinco Group, one of Sri Lanka's largest conglomerates, while de Mel is director of the group's energy company, Energen International Ltd. Ceylinco encompasses about 60 companies -- from insurance and tourism to property development.
However, these alternative-energy enthusiasts from Sri Lanka have been unable to elicit much support -- up until now. Ceylinco recently teamed up with German and Indian partners to form Energen International Consortium, which won a contract last year to build the world's first commercial solar-chimney project in Rajasthan, India, beating heavyweight American competitors like Enron-Amoco and Kentech Solar Energy Venture Inc.
Due to break ground by this year's end, the project will require an investment of $500 million. Much of that sum will be spent on glass to cover 10,000 hectares, in turn providing hot air to feed a massive 200-megawatt plant. The plant, scheduled to be built in stages, ending in 2001, is expected to start generating a limited amount of energy as early as next year.
Power from the solar chimney involves a huge upfront cost and its economic viability remains questionable. Still, some see promise in the scheme as increasing use of fossil fuels creates ever-bigger global pollution problems. Senanayake says the solar chimney should last more than a century, out-distancing conventional energy plants.
There would be no fuel costs, since air is free, and maintenance, beyond cleaning and repairing the glass, should be minimal. The plant should also produce energy around the clock, due to a unique feature of natural heat retention and radiation. The ground that is baked by the sun during the day will continue to heat air to power the plant at night, he says. In tropical countries, the solar chimney should generate power almost year-round.
At least, that's the theory. The concept was successfully tested from 1982 to 1989 in Spain in a pilot plant that generated 30 MW throughout a series of lengthy testing phases. The project was financed by the German government and designed by a professor of engineering at the University of Stuttgart, Jorg Schlaich.
Despite its promise, there was little follow-up to the experiment and Schlaich's solar brainstorm seemed destined for the dustbin. The idea was salvaged by chance in 1991 when a lecture by the professor was printed in a university publication sent to alumni. One former student happened to be a member of the new energy task force formed by Ceylinco. "We were instantly interested," recalls Senanayake. A few days later, he was in Germany, meeting with Professor Schlaich. A deal was quickly signed giving Ceylinco rights to the solar chimney for all of Asia. At the same time, Schlaich's engineering consultancy will offer technical expertise, plus financing in the form of grants, to get the new project going.
Yet, for all its enthusiasm, the group hasn't lit a fire in the energy field. There is currently only one small pilot plant on Ceylinco land. The logical next step for the evolution of this new technology is to build a medium-size plant of 30-50 MW. However, its energy would cost about twice as much as conventional power. A greater stumbling block is land. Not many nations with the money to finance a solar chimney have the thousands of unused acres needed to fuel them.
"Because of the limited experience with solar chimneys and the size of this project, there are going to be a number of problems," predicts U.S.-based energy expert Edgar DeMeo, manager of the renewables program at the Electric Power Research Institute, a clearinghouse for alternative-energy technology, located near San Francisco. "There will be technical challenges, environmental challenges and financial challenges," says DeMeo. "But at the same time, if these can be overcome and this can be built, it's possible that a significant contribution can be made."
For his part, Senanayake downplays the difficulties. "Of course, a chimney this tall has never been done before, but even 500 meters is nothing these days. Cooling towers are 300 meters. In engineering terms, it's just a bigger concrete tube. That should be no problem."
If it works, the Rajasthan project could change everything. Apart from proving the technology developed by Schlaich, who is a partner in the venture with Ceylinco, the plant could also pave the way for more solar chimneys. "Part of it is just investment in technology," explains Senanayake. "Right now, we are starting from scratch. With investment in this technology, the price will drop."
Even Sri Lanka is brightening to the possibilities. In June, Senanayake met with President Chandrika Kumaratunga and her cabinet. Sri Lanka, dependent on hydroelectricity, has been hit hard this year by a lack of rainfall. Though the solar chimney offers no near-term relief, the president told Asia, Inc.: "I'm quite keen on the idea. It's really remarkable."
Now, the hard part is turning the vision to reality. "We can make the desert bloom," promises de Mel. --- October 1996
Ron Gluckman is Hong Kong-based reporter who roams around Asia for a variety of publications including the business magazine Asia, Inc., which this story in August 1996. Ron Gluckman has a special interest in Sri Lanka; for a look at some of his other reporters from the island, see tourism, Life Under Seige and Arthur C. Clarke.
To return to the opening page and index