The Ituango hydropower station is a 2.4GW run-of-the-river hydroelectric power project under construction in the Antioquia region of Colombia.
The project is owned by Hidroituango, a consortium of Institute for Development of Antioquia (IDEA) and Empresas Públicas de Medellín (EPM). It is being developed by EPM with an estimated investment of approximately £3.82bn ($5.81bn).
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Although the construction works were started in September 2010, the project experienced delay following the collapse of an auxiliary diversion tunnel (ADT) in April 2018.
The first generating unit of the facility is expected to commence operations in 2022, while the project is expected to achieve full capacity by 2024.
Once fully operational, the Ituango power project is estimated to generate approximately 13,900GWh of electricity a year. It will be one of the biggest hydroelectric facilities in Colombia, capable of meeting approximately 18% of the national electricity demand.
Location and site details
The Ituango hydroelectric power project is located in the Ituango municipality, in the north-western region of Antioquia, approximately 170km northeast of Medellin, Colombia.
The project lies on the bank of the Cauca River, approximately 8km downstream of the Pescadero Bridge.
Ituango hydroelectric plant make-up
The Ituango hydroelectric power station will have an underground powerhouse comprising eight 300MW Francis turbines paired with vertical axis synchronous generators. The underground powerhouse will measure 240m-long, 23m-wide, and 50m-high.
The power plant is designed to operate at a hydraulic head of 197m.
The other major equipment of the power station includes three single-phase transformers for each set of turbine-generator assembly, a gas-insulated substation, and approximately 630km of the power transmission cable.
Reservoir and dam details
The Ituango hydroelectric power project involves a 225m-high earth-core-rock-fill (ECRF) dam with a crest length of approximately 550m. It creates a 76km-long reservoir with a design storage capacity of 2,720 million cubic metres (mcm).
The dam will have a controlled spillway with a design flow of 22,600 cubic metres a second.
Two parallel tunnels, each one kilometre long and 14m in diameter, have been excavated to divert water from the Cauca River.
The other supplementary components of the project include draft tube slide gates, four spillway radial gates (16,5m x 21m), 6.2m-diameter penstocks, intake gates, bulkheads, bottom outlet slide gates, and two tailrace tunnels to release the water back to the river.
Power evacuation
The electricity generated by the Ituango hydroelectric power station will be evacuated through a 500kV power transmission line to Colombia’s National Interconnected System (SIN).
Financing
The Inter-American Development Bank (IDB) signed a loan agreement of £744.16m ($1bn) for the project with EPM in December 2017. The loan agreement included a disbursement period of four years for partial finance of the project.
A group of International commercial banks and investors, including DPQ, KfW IPEX, BNP Paribas, ICBC, Sumitomo Mitsui, BBVA, and Banco Santander agreed to provide approximately £483.70m ($650m) for the project in 2018.
Contractors involved
ATB Group was awarded a contract worth £65.29m ($85m) for building the 6.2m-diameter penstocks with vertical steel shafts for the project in January 2020.
ATB Group was also engaged for the entire range of hydro-mechanical components of the project, including the draft tube slide gates, diversion tunnels gates, spillway radial gates, intakes gates, bulkheads, as well as intermediated bottom outlet sliding and radial gates during 2014 and 2017.
Alstom (now GE) was contracted for the supply, installation, and commissioning of turbines and generators of the project in 2012.
Comansa delivered three cranes for the construction works of the Ituango hydroelectric project in November 2017.
ABB was contracted for the supply of the gas-insulated switchgear (GIS) equipment for the project in December 2016.
A consortium of Conconcreto, Coninsa Ramón, and Camargo Corrêa was contracted for the civil construction works for the dam and the underground power complex in November 2012. The consortium was also contracted for the auxiliary diversion tunnel construction in December 2015.
Atlas Copco was contracted for the supply of stationary and portable compressors for underground, surface, and exploration drilling at the site in November 2012.
A joint venture of Ingetec and Sedic was selected for the supervision and project auditing services of the hydroelectric project in October 2011.
Ingeniería Supervision and Consultants provided consulting services of the project, while Sisgeo supplied and installed the geotechnical monitoring instruments for the diversion tunnel.
Gigacon was subcontracted for the assembly of the three cranes at the project site, while DYWIDAG was contracted to supply the drill hollow bars for slope and face stabilisation.
Ituango hydroelectric power project background
Hidroituango executed a binding agreement to develop the project on a build, operate, own, maintain, and transfer (BOOMT) basis in 2010.
While the environmental impact study (EIA) was carried out in 2007, the environmental license was granted by Colombia’s Ministry of the Environment, Housing, and Territorial Development in January 2009.
EPM signed extensions to the three main contracts comprising the consulting, contract supervision. and the construction of the hydroelectric project in December 2020.
