Salini Impregilo announced on 2 May that it had presented an offer to carry out the civil works for a US$ 600 million project to expand the 3.2 GW Yacyretà storage hydropower plant on the river Paraná, located on the border of Paraguay and Argentina. The project would increase the plant’s installed capacity by nine per cent or 270 MW, according to the Italian construction group.
Entidad Binacional Yacyretà (EBY), the bi-national owner-operator, invited bids in January of this year for work to add a new powerhouse with three vertical Kaplan units to the facility on the Aña-Cuá arm of the river. Offers for the civil works and certain electromechanical parts were due on 16 April, and with bids for the generation electromechanical supply on 2 May.
The multipurpose facility, which took 15 years to complete, was fully commissioned in July 1998 when the last of twenty 160 MW units began commercial operation. The powerhouse, located on the main arm of the river, generates on average 17 TWh/year, providing electricity for both the Argentinian and Paraguayan national grids. The plant supplies around 60 per cent of Argentina’s hydropower generation, equivalent to about 22 per cent of its electricity supply needs.
The facility comprises an earth- and rockfill dam with five sections with an overall length of 63.7 km, which extends across the two arms of the Paraná, impounding a reservoir with a surface area of 1600 km² and a storage volume of 21 x 109 m³, two spillways (a main weir with 18 radial gates with a discharge rate of 55 000 m³/s, and a secondary weir on the Aña-Cuá arm of the river with 16 radial gates and a discharge of 40 000 m³/s) and a navigation lock. In addition to power generation, the project facilitates river transport, fishing and irrigation. EBY is in the process of rehabilitating the units at Yacyretà to extend their lifetimes. As of the end of 2017, 12 of the units had been repaired.