Iceland Turns to Geothermal Energy
By “Awake!” correspondent in Iceland
WHAT can a country, such as the North Atlantic nation of Iceland, do when it has no fossil-fuel resources such as oil, coal or natural gas as an energy source?
A local advertisement reads: “Buy Icelandic, Use Icelandic Products.” This slogan has been taken seriously in the field of energy here in Iceland. While the immense power of several of the rivers has been tapped, this has not proved sufficient to reduce oil imports satisfactorily. Searching for another economical source, eyes turned to Iceland’s age-old foe, the volcano.
Could the tremendous energy of the volcano be harnessed—possibly not a volcanic eruption itself, but the chief by-product of volcanic activity, geothermal energy? Active volcanoes spew out molten lava, but these vast underground heat factories also make themselves evident through hot mud pits, geysers, hot springs and by the release of steam into the air. Iceland has subterranean reservoirs of superheated water, which, when tapped, is instantly converted into steam as it reaches the cold surface air. Steam, in turn, is an excellent form of clean and efficient energy.
Iceland is an island of the underwater mountain range called the Mid-Atlantic Ridge. Along the peak of this active zone of rifting and volcanism, which cuts through the center of Iceland, are 17 known high-temperature fields. In these regions are vast stores of superheated water, trapped in the rocks of the earth. How hot is such water? The highest temperature measured is approximately 340 degrees Celsius (644 degrees Fahrenheit). As the superheated water comes in contact with the air at the surface, it produces a deafening blast of steam. This steam can be harnessed to power a turbine, producing electricity.
The Icelandic National Energy Authority estimates that if the heat from these high-temperature geothermal fields were fully utilized, 10,000 megawatts (1 megawatt=1,000,000 watts) of electricity could be continually produced. Taking into consideration that Iceland uses only some 500 megawatts, we begin to realize the vastness of the unexploited energy available in this small country.
Aside from the high-temperature fields there are also very useful low-temperature areas supplying warm water. This is not bathtub-warm water. But at 80 degrees Celsius to 140 degrees Celsius (176 degrees Fahrenheit to 284 degrees Fahrenheit), this low temperature is considered too cold for producing electricity, though it is quite suitable for domestic and industrial purposes. As an example, Reykjavík, the capital, and several surrounding municipalities, have organized district heating systems to use the low-temperature geothermal fields on which they are built.
The History of Geothermal Energy Utilization in Iceland
At the turn of the 20th century few individuals gave any thought to using the country’s natural hot springs for anything more than an occasional bath in the outdoors. In Reykjavík, people would walk almost an hour to wash their clothing in a hot spring at Thvottalaugar. In 1928, a borehole was drilled at Thvottalaugar, producing water at a temperature of 87 degrees Celsius (189 degrees Fahrenheit). This was piped into a few public buildings and some homes three kilometers (nearly 2 miles) away. This experiment in community central heating proving successful, a search for more hot water got under way. In 1933, a large quantity was located at Reykir, some 15 kilometers (9 miles) from town, and in 1939 a pipeline was built between Reykir and Reykjavík. By 1943 the distribution network had reached most of the populated regions of Reykjavík. In the same year, the city saw the establishment of its Hitaveita, or District Heating Service. It began its service with a capacity of 200 liters (53 U.S. gallons) per second. Today there are some 2,000 liters (528 U.S. gallons) per second available, the equivalent of 420 megawatts of thermal energy. Of this immense supply, 25 percent is obtained from deep wells inside the city of Reykjavík itself.
Still further expansion is planned, by the utilization of more distant fields as well as by deeper wells. Even in Reykjavík (population, 84,000), the Hitaveita is planning 10 additional holes from 2,000 to 3,000 meters (6,560 to 9,840 feet) in depth.
The Advantages of Geothermal Heating
Geothermal heating creates many friends among the ecology-minded people of the world. In most modern cities, pollution is taking its toll on the environment, causing much irritation to all living organisms. Reykjavík was once a smoke-filled city too, but times have changed. Because of using clean and efficient geothermal energy, this city is free from the deadly pollution created by the burning of fossil fuels. Today it is called the smokeless capital of the world.
The cost of utilizing geothermal energy is far less than that of burning imported fuel oil to produce heat or electricity. As an example, a home that would consume approximately 40,000 kilowatts of energy yearly would cost 324,300 Icelandic Krónur ($1,273, U.S.) for oil, whereas, with geothermal methods, the total yearly cost could be as low as 88,310 Icelandic Krónur ($347, U.S.).
Simplicity is also a key factor in the use of hot spring water to heat homes. The hot-water pipes are well insulated so that precious heat is not lost. Each household has a hot-water meter, which is read by the same person reading the electric meter. The same water is also clean enough to serve other domestic purposes, being used directly from the tap for bathing, washing and some cooking.
How would you like to be able to go swimming any time of the year in a heated outdoor swimming pool? The city of Reykjavík operates two such outdoor pools so that the public can swim in 26-degree-Celsius (79-degree-Fahrenheit) comfort, no matter how cold the air temperature might be. Today the Laugardalur swimming pool has replaced the old washing spot at Thvottalaugar. Another unique feature at Laugardal is four sitting pools, each kept at its individual constant temperature. As many as 15 persons can sit in each of these pools, relaxing in water of 32 degrees Celsius to 45 degrees Celsius (90 degrees Fahrenheit to 113 degrees Fahrenheit). Sufferers from rheumatism and other inflammatory ailments find relief by daily visits to these “hot pots.” It is no wonder that these health-invigorating centers are so popular with the city’s inhabitants and visitors alike. People in the city of Reykjavík pay only 120 Icelandic Krónur ($0.47 U.S.) per visit, with discounts for children and the elderly, and with no charge for the lame.
Can Rural Areas Benefit from Geothermal Energy?
What about the remaining 100,000 inhabitants scattered about in the many small towns, villages and farms? Can their energy needs also be satisfied by harnessing some form of geothermal energy? The National Energy Authority estimates that as a result of the present price of alternative energy resources, 70 percent of the population will be using geothermal heating methods in the near future. For the remaining 30 percent of Iceland’s inhabitants, electrical heating produced through the less-expensive geothermal process will still be more economical than it would be if produced from fossil fuels.
The new Hitaveita Sudurnesja (Sudurnes District Heating Service) has been in operation since late 1976. This system will eventually provide geothermal heating for the homes of 11,000 persons. Akureyri, the largest town in the north (12,000 population), and several of the villages have already developed community heating systems. Prospects of piping hot water to some of the villages along the west fjords also seem promising.
Geothermal Power Plants
Utilizing steam from high-temperature geothermal fields to produce electricity is a difficult task, demanding the use of the most modern engineering technology. One such power plant is near beautiful Lake Mývatn. It has proved its reliability by operating with an output of three megawatts since its opening in 1969. Presently, construction of a second steam-electric facility is progressing at the foot of Mount Krafla. It is planned that steam be obtained from many holes at depths of 1,500 to 2,000 meters (4,920 to 6,560 feet) in a 35-square-kilometer (13.5-square-mile) geothermal field. Thus far the steam from this field has exceeded 340 degrees Celsius (644 degrees Fahrenheit), giving engineers hope that this new facility will eventually be capable of producing some 70 megawatts of electricity.
Despite occasional eruptions of lava and sudden, powerful uncontrollable blasts of steam, the Krafla power-plant project continues to progress toward completion. Although the future of such plants may seem excellent to some, they must be built near, if not on top of, high-temperature geothermal fields in order to reach peak productivity. Therefore we see that there is considerable risk in producing electricity by this means. Only time will tell if the latest power project at Krafla proves completely successful in utilizing the earth’s steam, thus justifying the risk.
The Hot Rock Project of Heimaey
Now Iceland is developing a method of harnessing another source of geothermal heat—the hot lava field. For the people of the Vestmannaeyjar (Westmann Islands) off the southern coast of Iceland, this seems to be the best source of energy. These islands do not appear to have natural springs with hot water in practical quantity, so there is no choice but to look to the volcano and its by-product, hot lava.
Early in 1973, the 5,500 inhabitants of Heimaey were forced to evacuate the island after a fissure eruption began just outside the town. Within weeks, a third of the town was engulfed in lava from the newly created volcano. Several months later, it ceased spewing molten lava, and people started moving back onto the island to clean up the rubble and resume ordinary life. What would be better than, if possible, to utilize the heat from their newly formed enemy?
The energy from Heimaey’s new lava field can be tapped and used to heat the town’s buildings. Pipes sunk into Heimaey’s fresh lava bring steam and gases to the surface, which, in turn, heat water in the municipal heating system. This being a complete and closed cycle, water at 80 degrees Celsius (176 degrees Fahrenheit) is sent out into the space-heating system of Heimaey, and is returned for reheating when it has cooled down to 40 degrees Celsius (104 degrees Fahrenheit).
It is planned that all the town’s houses will shortly be able to benefit from this new heating system. Experts believe that as the upper layer of lava eventually cools, the pipes can be sunk deeper into the lava until sufficient heat is reached. It is thought that the Westmann Islanders will be able to use the Hraun-hitaveita (Lava District Heating Service) for many decades before the field gets too cool for economical use.
Greenhouse Farming
In a land as far north as Iceland, the climate and the short growing season place considerable limitations on farming. As a result, only a few vegetables can be successfully grown out in the open. But due to usage of geothermal energy, the Icelanders are not tied to conventional methods of farming. Natural heat from the earth is used to warm approximately 14 hectares (35 acres) under greenhouse cultivation. By this means tomatoes, cucumbers and many flower varieties are grown in an otherwise limited growth area. Other varieties of vegetables can also be cultivated in certain regions of Iceland where the soil itself is naturally warmed, of course, by geothermal energy.