Survey of Energy Resources 2007
Geothermal Country Notes
The Central American volcanic belt passes through Costa Rica, evidenced by numerous volcanoes and geothermal areas. The fields of Miravalles, Tenorio and Rincón de la Vieja are located in the north-western part of the country and have been studied in detail.
To date, Costa Rica's geothermal resources have been utilised almost entirely for electric power generation. A 55 MWe single flash condensing unit was commissioned in 1993 at Miravalles, followed soon afterwards by an additional 5 MWe back-pressure unit. A second 55 MWe condensing unit came on stream in 1998, and subsequently (in 2000) another 29.5 MWe back-pressure unit. With the commissioning of a further 18 MWe unit in December 2003, the total installed capacity now stands at 162.5 MWe.
The Instituto Costarricense de Electricidad (ICE) owns and operates Miravalles, with the exception of the 29.5 MW plant, which operates under a 15-year BOT contract.
Exploration work on the slopes of the Rincón de la Vieja volcano at the Las Pailas and Borinquen geothermal fields has resulted in the discovery of high-temperature fields.
Following the feasibility study for a 35 MWe plant at Las Pailas, ICE will start construction of the first unit during the second half of 2007. Further drilling will take place prior to a feasibility report for the second unit. It is expected that studies will be completed by 2010; the first unit will be on line in January 2011 and the second by July 2014.
The feasibility study on the Borinquen field was 40% complete when it was halted and exploratory work moved to the Las Pailas field. The two are less than 9 km apart, but it is considered that they are fed by separate reservoirs. The feasibility study is now expected to be completed in 2013, with the first unit scheduled to be on line in November 2018.
In the last 20 years, with the help of the Italian Government and the United Nations Development Fund (UNDP), Costa Rica's low- and medium-temperature resource has been studied. However, at the present time direct use is confined to hotel swimming pools in areas of ecotourism.