Hydropower in the Pan Amazon: An overview of the private energy sector in Ecuador and China’s role

The recent history of hydropower in Ecuador is similar to that described for Bolivia and Peru, particularly with respect to its recent expansion and the predominance of D&T systems that exploit the geographic advantages of the Andean Cordillera. Like Bolivia, the state has assumed a near monopoly on generation and has turned to China for technological assistance and financial capital. In 2013, Ecuador sourced about 40 per cent of its electricity from hydropower but increased its contribution to 58 per cent by 2019, while national consumption grew by forty per cent. Approximately, eighty per cent of Ecuador’s installed hydropower is generated by power plants on the Napo, Pastaza and Santiago watersheds.

Much attention has focused on the recently inaugurated large-scale project with the unusual name of Coca Codo Sinclair. The design of this new power plant takes advantage of a 650-metre vertical drop that includes a natural waterfall and multiple rapids across about 75 kilometers of river channel. The D&T design diverts water through a 25-kilometer tunnel to turbines at the bottom of the bend with installed capacity of 1.5 GW. It is the largest power plant in Ecuador and supplies about 25% of the national electricity demand.

Like most mega-scale projects, it was conceived in the 1950s and underwent multiple iterations before being commissioned by the Ecuadorian government in 2009. It is operated by a subsidiary of the national electrical monopoly Corporación Eléctrica del Ecuador (CELEC), but was built by a Chinese construction company, Sinohydro and financed by the Export-Import Bank of China.

The direct environmental impacts appear to be moderate. The reservoir is only 300 hectares and sediments are flushed back into the Coca River periodically; the barrier to fish migration was pre-existing because of the presence of the San Rafael Falls, which are located between the dam and the powerhouse. The facility is located between two national parks, PN Cayambe Coca and the PN Sumaco Galeras, but all of the infrastructure is located on a river valley previously impacted by the right-of-way for an oil pipeline and deforestation along the Troncal Amazónica. The area is sparsely populated, and there is little evidence that local populations have objected to its development.

An unexpected event now threatens the physical integrity of the hydropower complex. In February 2020, the river eroded a channel underneath the lava dyke that created the waterfall and left the once magnificent cascade a mere trickle of water. Once the solid rock of the lava dyke was isolated from the erosional forces of the river, however, the river started to erode through the loosely consolidated sediments of the Coca river floodplain. By December 2020, the top of the waterfall, now a series of rapids, had migrated approximately three kilometers upstream towards the dam and intake tunnel.

At the current rate of erosion, the top of the cascade could reach the dam in approximately two years, which could force the operators to close the tunnel leading to the power plant. The vertical drop between the dam and the bottom of the falls is similar to equivalent stretches of the river below the falls and above the dam; consequently, civil engineers will probably be able to safeguard the installation. Nonetheless, the incident calls into question the competence of the original feasibility study and the EIA, as well as the wisdom of building a strategically important infrastructure asset at the base of an active volcano (El Revantador).

In spite of its size, the Coca Codo Sinclair is not the largest hydropower complex in Ecuador; that distinction belongs to a cascade of dams and powerplants on the Rio Paute, a tributary of the Santiago River. The Centro Hidroeléctrico Hidropaute began with the inauguration of the Molina D&R unit in 1983 (500 MW) and its expansion in 1991 (600 MW), which was followed by the construction of the D&T units at Mazar in 2010 (170 MW) and Sopladora in 2018 (385 MW). A fourth unit, Cardanillo (596 MW), is under development, and when it is completed, the total combined capacity from the four facilities will exceed 2.1 GW. The CH Hidropaute is another subsidiary of CELEC, and its newest addition was built by the China-Gezhouba Group with loans from the ExIm Bank of China.

Further expansion is being planned for the Rio Zamora, the southern branch of the Santiago River, with a projected combined capacity of between 5 and 7 GW. The most likely design foresees three D&R units in a cascade though a narrow valley that transects the Cordillera del Condor. Such a design would not be unlike the proposed ‘Pongo’ dams on the Rio Marañon and the El Bala/Chepite project on the Rio Beni. Ecuador has many options for renewable energy, particularly wind and geothermal, but hydropower is the largest component of its future development plans.

“A Perfect Storm in the Amazon” is a book by Timothy Killeen and contains the author’s viewpoints and analysis. The second edition was published by The White Horse in 2021, under the terms of a Creative Commons license (CC BY 4.0 license).

Read the other excerpted portions of chapter 2 here: