In the 1970s, Iceland was one of the poorest countries in Europe. Today it is one of the richest, with a per capita GDP higher than that of Denmark, from which it won full independence in 1944.

How did it accomplish this remarkable transformation? A key element was the shift from imported coal and oil to geothermal energy. Iceland now uses geothermal energy to generate a large portion of its electricity and nearly all of its heating needs.

Iceland’s president Ólafur Grímsson was at Harvard on Tuesday (Sept. 25) to deliver this inspiring message and to announce that his country stands ready to lead the world toward a cheap and pollution-free energy future. His talk, “Geothermal Energy: Harnessing the Fire Inside,” was sponsored by the Center for the Environment, the Center for European Studies, and Bank of America.

The debate on global warming is really a debate about how we can satisfy our energy needs without endangering the planet, Grímsson said. Of the potential energy resources available to us, only two are completely clean: solar and geothermal. The second of these, however, has been neglected.

“We are reminded of the fireball inside the Earth when natural disasters such as earthquakes and volcanic explosions occur, but these disasters should also remind us of the colossal source of energy inside the Earth,” he said.

Icelanders have been aware of their country’s underground thermal activity since Vikings discovered the island in the late 9th century. The name of the capital city, Reykjavik, means “Bay of Smoke.” But it was not until the 1930s and ’40s that geothermal resources began to be tapped for heating purposes. The technology grew from small-scale operations to the present nationwide system.

“Most energy developments have started from small beginnings,” Grímsson said.

While Iceland, a country rich in volcanoes, geysers, and hot springs, may seem an obvious candidate for the exploitation of geothermal energy, many areas of the world are blessed with equal potential, Grímsson said. Areas of volcanic activity exist on every continent, offering opportunities to tap into the Earth’s buried sources of energy.

In collaboration with the United Nations, Iceland has been offering technological assistance to countries that want to develop geothermal projects of their own.

In the city of Xian Yang in China, the first stage of a new geothermal heating system, built in partnership with Icelandic companies, recently got up and running. When finished, it will be the largest of its kind in the world. Icelandic energy companies also have been involved in geothermal projects in Europe, Asia, and the United States.

In addition, Iceland has been active in training people in geothermal technology and in raising awareness of climate change. Hundreds of individuals from all over the world have graduated from the United Nations Geothermal Training Program, located in Iceland, while earlier this year, Grímsson helped organize a conference of African leaders to discuss the geothermal potential of the African Rift Valley.

Iceland’s success in developing geothermal energy is only a first step, Grímsson said. There are other exciting clean energy technologies that his country is currently exploring. One project currently under way in Iceland is an attempt to drill down five kilometers into the Earth to reach even greater heat sources, estimated at 400 to 600 degrees centigrade. How such heat can be successfully harnessed is still under study.

Another promising resource is the Kalina technology, named after the Russian scientist Alexander Kalina. In this process, geothermal energy is combined with the energy produced when water and ammonia evaporate. Another promising initiative currently under investigation is tapping into the geothermal resource that exists on the ocean bottom.

One reason his country has taken such an active role in promoting renewable energy, Grímsson said, is that Iceland itself is extremely vulnerable to the effects of global warming. Melting of the icecaps and subsequent reduction of the salinity of the oceans could change the ocean currents that keep Iceland relatively warm. If these currents no longer flow, Iceland could become so cold as to be uninhabitable.

But in the meantime, Iceland intends to fight for clean energy, and even countries as large and powerful as the United States might benefit from its knowledge and experience, Grímsson said.

“Geothermal power might become a dominant clean energy resource in the United States if the necessary technological leadership and the necessary political leadership can join hands in this area.”