San José, Costa Rica, since 1956

Costa Rica Replete With Geothermal Hot Spots

Fifth in a Series on Energy in Costa Rica


Costa Rica is red hot with spots to generate geothermal energy (see map).

Thanks to a landscape that is dotted with both explosive and sleeping volcanoes and that rests over underground lava pits, the country has the potential to produce 860 megawatts of geothermal energy, according to a recent study by the Costa Rican Electricity Institute (ICE), or about 40 percent of the electricity that the country currently produces.

Creating geothermal energy is a process that involves using underground, geologic heat to turn water to steam and, in turn, using this steam to turn turbines that produce electricity.

But because most of that energy is within the boundaries of national parks, where it is illegal to build electrical plants, ICE can take advantage of only about 20 percent of the nation’s geothermal energy potential.

Costa Rica’s lone geothermal facility is Miravalles, in rural Guanacaste, a province in the northwest corner of the country.

It produces 163.5 megawatts of electricity. The five plants that make up the Miravalles complex have accounted for an average of 14 percent of the country’s electricity during the past four years.

Most experts agree that geothermal is a clean way to generate electricity and the most consistent one of the mainstream renewable energy sources.

Because the earth’s naturally produced heat does not depend on the weather, a geothermal plant can produce energy 24 hours a day, seven days a week, unlike its renewable counterparts of wind or hydroelectric power.

Geothermal plants also emit 15 times fewer gasses and cost about 10 times less per kilowatt-hour than petroleum-using thermal plants, according to Alfredo Mainieri, director of ICE’s Center for Geothermal Resources.

The ICE cited all of these benefits as reasons to pass a law that would allow further exploration of geothermal resources in Costa Rica.

In 2005, the government electricity monopoly presented a bill that would have opened national parks to the exploration and extraction of geothermal energy. But, following four years of circulation through the Legislative Assembly, the project was filed away in early July after legislators deemed the proposal unconstitutional and conservationists pegged the idea as environmentally harmful.

Since the bill did not contain a plan for conducting an environmental impact study, nor did it offer compensation for environmental damage that might be caused during plant construction, lawmakers considered the initiative not in accordance with Article 50 of the Costa Rican Constitution, which guarantees Ticos the right to a healthy and ecologically balanced environment.

In its place, the president of the Legislative Assembly’s Environment Commission, Maureen Ballestero, proposed a bill that would allow ICE to explore geothermal energy inside national parks, but from a distance and with limitations.

Ballestero’s plan allows exploration only in the volcanic mountain ranges of Guanacaste and Tilarán. ICE would have to build plants outside of the limits of the national parks and run subterranean tubes into the parks to carry the steam produced to outlying plants.

ICE’s Mainieri said these mountain ranges have shown great potential for geothermal energy. He noted, though, that the construction of long, underground tubes can be costly and it also can contribute to inefficient electricity generation since steam would have to travel further and it would have more time to cool and condense.

“The temperatures of these interior lands are too high to not take advantage of them on the spot,” Mainieri said. “The highest temperatures are located next to the volcanoes, or, in other words, inside national parks. To best use this heat, a plant should be built as close to the heat deposits as possible.”

Mainieri reported that the Central Volcanic mountain range of Guanacaste has produced temperatures of 240 C (464 F). The Miravalles plants have found pockets of up to 280 C (536 F).

Gino Viamonte, president of the Wild Flora and Fauna Preservation Association (APREFLOFAS) and an environmentalist who opposed the initial ICE bill, said he would support a geothermal project as long as it can be proved to have a minimal impact on the environment.

“Technically, if it doesn’t do any damage, it could be an exception,” he said. “The problem is that the construction, the building of roads in and out of the parks, well, this does a lot of damage in the long run.”

But Mainieri shrugged off such environmental concerns as charges of those who have never visited the Miravalles facility.

“Since the ICE bought the 10-square kilometers (of land) for Miravalles 25 years ago, the transformation has been evident,” he said. “They converted the area from being empty fields to a zone covered by dense forests surrounded with species that had disappeared from the area.”

ICE has used a portion of the electricity tax to reforest the area surrounding Miravalles. Ballestero’s geothermal plan, although not yet official, also calls for one percent of generated electricity sales to be dedicated to protected wildlife areas.

Next week: Solar Energy



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