As reported today by Renewable Energy Magazine, El Salvador is one of three countries in the world where geothermal resources make up at least one fifth of the energy consumed – Iceland and the Philippines also rely heavily on geothermal energy. LaGeo, a Salvadoran corporation, owns and operates El Salvador’s two geothermal power plants – one in Ahuachapán and another in Berlín, Usulután – with two more under construction in Chinameca, San Miguel and San Pablo Tacachico, La Libertad. In 2009, the Ahuachapån and Usulután geothermal plants produced up to 26% of all energy produced in El Salvador.
The Ahuachapán plant has the capacity to produce 95MW, though its generating average is 58 MW per hour. The Usulután plant has an installed capacity to produce 66 MW, though it can produce as much as 109 MW per hour.
Geothermal energy is thermal energy stored at an accessible depth of the earth’s crust, and is thought to be one of the most sustainable and environmentally friendly sources of electricity. It is created when groundwater seeps through the earth’s surface and is trapped in large reservoirs, where it is heated to very high temperatures by magma and the decay of naturally radioactive materials such as uranium and potassium. According to the Union of Concerned Scientists, “the amount of heat within 10,000 meters of earth’s surface contains 50,000 times more energy than all the oil and natural gas resources in the world.” Geothermal plants dig deep wells and extract water heated by the magma, the steam from which turns turbines that generate electricity. Though capital costs in drilling the boreholes and building the plants can be high, once they are up and running geothermal plants can produce energy at 1/3 the cost of energy generated by oil.
The greatest environmental hazard of geothermal energy is related to the disposal of the unused water brought to the surface, which is extremely hot and potentially contaminated by boron or other hazardous materials. Geothermal plants mitigate these risks by re-injecting the water back into the underground reservoir where it can be reheated by magma.
In addition to geothermal power, El Salvador generates hydroelectric and thermal energy, and purchases energy from foreign sources. In recent years the government has produced strategies to promote renewable energy, and in March 2010, the Japanese Aid Agency announced that it would fund a study to look at energy production in El Salvador.