Conceptual Model of the Amatitlan Geothermal Field, Guatemala.
- M. Momita, T. Fujino, E. M. Lima Lobato, J. J. Palma
- Chinetsu, v
uring the early 1970s, the Organization for Overseas Technical Cooperation Agency (OTCA, now the Japan International Cooperation Agency, JICA) assisted the Instituto Nacional de Electrificacin (INDE) in the assessment of Guatemala’s geothermal resources. Subsequently, several projects were carried out using INDE’s own funds and those of a number of financial institutions—the Inter-American Development Bank (IADB), Organization of Petroleum Export Countries (OPEC), Latin American Energy Organization (OLADE), Regional Office for Central America Programs/U.S. Agency for International Development (ROCAP/USAID), European Community, Japan International Cooperation Agency (JICA), and the International Atomic Energy Agency (IAEA). Because of its strong surface manifestations, Moyuta (Site 12 in Fig.1) was the first area to be studied (1972). Two production-size exploration wells were drilled in the area in 1975, but disappointing downhole temperatures diverted the focus of exploration work to the Zunil, and later to the Amatitlán, geothermal areas (Sites 2 and 5 in Fig.1). After completing preliminary surface surveys, INDE drilled several slim holes in both fields. In 1981, to improve the geothermal resource inventory for the country and establish study priorities, INDE and the Bureau de Recherches Géologiques et Minières (BRGM France) began carrying out exploration surveys in the 13 geothermal areas shown in Figure 1, under a co-financing agreement between INDE and OLADE. All the sites are located within the southern east-west volcanic cordillera that extends across the country and covers 30 percent of Guatemala between its borders with El Salvador and Mexico. As a result of these studies, and those carried out by OTCA in the 1970s, the Zunil and Amatitlán geothermal areas received the highest priority for further study and possible development. A somewhat lower priority was assigned to San Marcos and Tecuamburro. Lower priorities were given to Los Achiotes, Moyuta and Ixtepeque-Ipala, while the areas of Palencia, Retana, Ayarza, Atitlán and Motagua were assigned to the lowest (fourth) priority category. In 1993, with IAEA’s technical cooperation, the Totonicapán geothermal area was also identified as high-priority. Geothermal resources in Guatemala are estimated at 800 to 4,000 megawatts (MW) capacity, most likely about 1,000 MW (Lippmann, 2002). Considering that the country’s current installed electricity generation capacity is 1,700 MW, geothermal energy could contribute significantly to a secure power supply to meet future electricity demands. The most serious impediment to this outcome is investor perception of risk, considering the high up front investment required to find and confirm the existence of commercial-size geothermal resources, and in the time required to amortize such investments. Unfortunately, the amortization period usually begins at a time when the Past, Present and Future Development of Geothermal Energy in Guatemala