Survey of Energy Resources 2007
Hydropower Country Notes
In the context of energy supply, Paraguay's outstanding natural asset is its hydroelectric potential, which is mainly derived from the river Paraná and its tributaries. The country's gross theoretical capability for hydroelectricity is about 130 TWh/yr, of which 101 TWh is estimated to be economically exploitable. Two huge hydroelectric schemes currently utilise the flow of the Paraná: Itaipú, which Paraguay shares with Brazil, and Yacyretá, which it shares with Argentina.
Itaipú is the world's largest hydroelectric plant, with a total generating capacity of 12 600 MW at end-2005, of which Paraguay's share was 6 300 MW. This share is far in excess of its present or foreseeable needs and consequently the greater part of the output accruing to Paraguay is sold back to Brazil. Itaipú's 19th 700 MW unit entered commercial operation in September 2006, bringing total capacity at the site up to 13 300 MW. The 20th 700 MW generator is expected to come on line during 2007. Electricity generation at Itaipú in 2006 totalled 92 690 GWh.
The bi-national plant at Yacyretá, downstream from Itaipú, has an installed capacity of 3 100 MW. There are 20 generating units, each of 155 MW capacity, but all are still operating at only 90 MW per unit, owing to the level of the reservoir being held below that originally planned.
Paraguay has a wholly-owned 210 MW hydro plant (Acaray), which will probably be uprated by 45 MW during the next few years. The state electric utility, ANDE, also plans to install two 100 MW units at Yguazu. An environmental impact study has been conducted for the projected bi-national Corpus Christi dam (2 880 MW, to be shared with Argentina), sited on the Paraná, downstream of Itaipú and upstream of Yacyretá.