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BY HENRY PETROSKI

Visiting an Exotic Place

Iceland is an environmentalist’s paradise and an engineer’s playland.

Photo: HENRY PETROSKI - geothermal power plants can remind us of chemistry lab.The University of Iceland celebrated its 100th anniversary last year, and I was happy to have been invited to be the honorary speaker for the School of Engineering and Natural Sciences. Participating in the centennial event gave my wife and me an opportunity to learn more about the exotic land.

Iceland is not very densely populated. Its approximately 100,000 square kilometers of land are inhabited by about 320,000 people, more than a third of whom live in the capital city of Reykjavík. But what it may lack in population density, the island nation more than makes up for in hospitality — and geological features. After my talk, the school’s dean, who is a geologist, the head of the faculty of civil and environmental engineering, and the school’s director of marketing gave up their Sunday to show us around.

Striking sites abound on this island in the North Atlantic that is located about midway between North America and Europe. Its horizon is interrupted by conical volcanoes; its ground is punctuated with steaming geysers; its shoreline is sliced by steep fjords; its interior is deep in glaciers. There are very visible earthquake rifts, even one preserved (and instrumented) under Plexiglas in a shopping center. Underground, there are pockets of geothermal energy, ready to be exploited to produce inexpensive green power.

Iceland would thus seem to be a geologist’s museum, an outdoorsman’s dream, an environmentalist’s paradise, and an engineer’s playland. And indeed engineers have been tapping into the geothermal reservoirs with deep boreholes to reach down to pockets of heat within the Earth and bring their energy to the surface to drive steam turbines that in turn drive electric generators.

In fact, about 25 percent of the country’s electric power comes from geothermal sources, with the other 75 percent being from hydroelectric. In addition, residents of Reykjavík need not burn wood or coal or gas or oil to heat their homes; that is done by means of hot water that is a byproduct of the geothermal process. This means, of course, that the air in the city is extremely clean; other than vehicles there are none of the usual sources of pollution to make it otherwise.

On our way to the Keflavik International Airport to catch our flight home, we stopped at nearby Grindavík to visit the celebrated Blue Lagoon, whose waters are really the effluent from the 75-megawatt Svartsengi Power Station, Iceland’s largest geothermal plant. The seawater-blue color is due to its high concentration of sulfates, which promote the growth of algae. The minerals in the water are also believed to give it curative powers, and swimming in the Blue Lagoon is a popular tourist activity, especially for those suffering from such skin maladies as eczema and psoriasis.

As blue as it makes the water and as green as it provides the power, there are some drawbacks to geothermal energy. Approaching a power plant from downwind brings the greeting of a strong odor of rotten eggs, which brought back memories of the hydrogen sulfide gas we produced in freshman chemistry lab. The presence of the gas also creates problems for the steel transmission towers that carry the electric power to its destination, with the caustic atmosphere visibly corroding them.

Engineers are working on these problems, but in the meantime people have gotten used to the aura of hydrogen sulfide about the geothermal plants and the patina of corrosion on the towers. They are but reminders of the fact that no matter how thoughtfully we might exploit the Earth’s resources, our intervention yields by-products with which we must deal.

 

Henry Petroski is the Aleksandar S. Vesic Professor of Civil Engineering and a professor of history at Duke University. His new book, To Forgive Design: Understanding Failure, has just been published by Harvard University Press.

 



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