May 18, 2011. Colombia and Ecuador will cooperate on a 138-megawatt geothermal project planned for their border as both South American countries seek to diversify their power output from hydroelectricity. The Binacional Tufino-Chiles-Cerro Negro project will be developed by Colombia's state-controlled power company Isagen SA and its Ecuadorian counterpart Celec SA. Both countries produced more than 60 percent of their electricity from large hydroelectric facilities in 2008. The companies will drill holes over a terrain of 5,000 hectares (12,400 acres) to gauge the site's geothermal resources.