Geothermal developments in Iceland: What the pipes let through

Around a hundred million tons of carbon dioxide get into the atmosphere of Reykjavík through its heating that is based on hot water bursting out of ground sources. This fact made Icelanders wonder what to do with the surplus energy.

Even a shower can serve as a reminder that the geothermal energy has a major role in the Reykjavík’s energy supply.  The hot water pouring out of the shower head comes directly from water springs located one or two kilometers beneath the ground, and the dissolved sulfur compounds that smell like rotten eggs are impossible to ignore. In hotels, guests are warned that, although the water is potable, one should leave the tap running for a while so as to fully enjoy it as the top quality potable water in the world.

Geothermal energy is used almost everywhere in Iceland. The country itself is an island about the size of Hungary that has a population of 320,000 which lies at the junction of the European and North American tectonic plates.

A water reservoir in Reykjavík

The waste heat produced in the country is used to warm its 740,000 square meters long public road. Out of this surface, 550,000 square meters of road are in Reykjavík, and another 40,000 square meters are the heated downtown pavements located in the Icelandic capital. Orkuveita Reykjavíkur (OR), the energy supply company serving the capital and its surroundings, circulates 75 million cubic meters of water through its 2,700 kilometer long pipe system that has a maximum capacity exceeding 20,000 cubic meters per hour. By law, it also has to pump the water back into the ground. Massive containers able to hold 20 million liters of hot water during winter were built in Perlan, in the southern part of Reykjavík, where a Viking museum and a winter garden attract many visitors all year round.

While water springs at a temperature of around 100 Celsius degrees feed the hot water and heating pipelines, the water with a temperature of over 200 Celsius degrees is also used to generate electricity. The newest power plant built at Hellisheid with an investment of 800 million USD operates at an electric power-generating capacity of 300 megawatts, while its thermal capacity is at around 150 megawatts.

The Blue Lagoon spa complex situated halfway between the Keflavík international airport and Reykjavík is the most efficient example of how versatile water use can be. The Svartseng power plant produces electricity by using the steam of water heated by lava, and the cooling water is run through heat exchangers which also heat the neighboring settlements. The cooled water has a temperature of 37 to 39 Celsius degrees, is rich in minerals and it is used to flood the 5,000 square meters large outdoor lagoon visited yearly by 500,000 people.

Hot springs in Iceland

So far, the geothermal energy seems inexhaustible. However, the Icelandic authorities regularly warn people that they should save their resources. “We have designed energy prices that prevent waste”, said Eiríkur Hjalmarsson, a press officer of OR. He explained that the massive development of geothermal energy in Iceland started after the oil shock of the 1970s. Since the mid-nineties, no oil or gas is used for heating in a country that is geologically the youngest on Earth: half of the island emerged from the sea less than one million years ago.

The debate about the surplus energy derived from the renewable resources is ongoing. Hydroelectric power plants produce 12,000 gigawatt hours, and the geothermal power stations generate 5,000 gigawatt hours. “One possibility is to build underground cables that would export the additional energy. Similar plans are designed for Oslo: the preparations to build a 750 kilometer long high voltage cable between Norway and Great Britain have started. But more and more people believe that the domestic industry in Iceland should be further developed instead, which would enable us to use the electricity with a greater added value” – said Hjalmarsson.

One of Iceland’s geysers.

While Iceland is the leading country in the world for geothermal energy consumption per capita, 15,000 gigawatt hours per year of this energy is produced by the United States, an amount that constitutes only 0.3 percent of the electricity produced in this country. Native Americans considered hot water springs sacred places before the arrival of the white colonizers, and members of rival tribes would even have baths next to each other despite their differences. There are 77 geothermal power plants in operation in the USA, the largest ones being located in California. The second worldwide producer is the rapidly developing Philippines, where 17 percent of the total energy comes from underground hot water springs. The first geothermal power station in the Philippines was built in 1977. Since then, new ones have been built at a fast rate, while the older ones have been increasing their capacities.

In Europe,Italy takes the lead in this respect. The first geothermal power generator, which later became a power plant, was built in Larderello in Northern Italy at the beginning of the twentieth century. Its energy could initially light less than four light bulbs, but nowadays it generates 10 percent of the world’s geothermal energy, or 4,800 gigawatt hours, which supply a million of Italian households with electricity. The Larderello power plant uses hot springs as its source. The springs, which were also known by the ancient Romans, were seen as such an innovative source of energy that a second plant of this kind was built half a century later in Wairakei, New Zealand.

András Németh is a reporter for HVG. This article was produced for the Next in Line project, co-funded by the European Union, and originally appeared in the daily newspaper HVG. Translated by Borbála Tóth. Photos by András Németh