Gibe III Hydroelectric Project

Gibe III Virtual Tour

Gibe III Hydroelectric Project (1870 MW)

Contract signed: 2006
Client: Ethiopian Electric Power (EEP)
Value: € 1.47 billion

 

Today, Gibe III has become reality. The hydroelectric plant has started functioning. It has taken many years of work, but what was just one of the largest worksites in Ethiopia has now come to life. Gibe III represents the third stage of an ambitious energy development project that was inaugurated in 1999, when works for constructing Gibe I started, the first dam on the Omo River.

Gibe I was completed in 2004. In the same year, works to build Gibe II started (the dam was completed in 2009).

The last dam is the evolution of a project that aims at using the hydroelectric potential of the valley, by building a series of hydroelectric plants capable of producing renewable energy and of fulfilling Ethiopia's development needs. Gibe III, the most powerful hydroelectric plant of the three, is capable of producing 6,500 Gwh of electricity each year, avoiding 4.5 million tons of greenhouse gas emissions. It therefore offers an effective answer to these needs.

 

GIBE III

Gibe III is an impressive dam. The hydroelectric plant will increase Ethiopia's energy production by 85% and will allow the Country to increase the sale of energy to the neighbouring countries like Kenya, Sudan and Djibouti

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Its construction required the allocation of €1,470 million, funded by Ethiopian Electric Power and by China’s "Exim Bank".

The project is located on the Omo River, approximately 300 Km south-west of Ethiopia's capital, Addis Ababa. It comprises an RCC dam and an open-air powerhouse with 10 Francis turbines that offers an overall installed power of 1,870 MW. The project also included 3 diversion tunnels and 2 twin pumping tunnels, 2 intake structures, 2 horizontal tunnels, 4 vertical wells and 2 distributors.

The dam measures 250 m in height. At the moment, it is the world's highest RCC dam. It is also located in a remote area, with unique logistical and technical challenges.
Concrete (RCC) laying activities began in 2011. The dam's pre-impounding operations were carried out in August 2014 and the final impounding phase was completed during the first months of 2015, while the project was inaugurated in December 2016,  

Gibe III represents an engineering reference point at a global level. This is due to the technical characteristics that distinguish the project and to the number of workers: 8,000 people, the vast majority of Ethiopian origin, were present at the worksite during peak occupational periods.

Many challenges were met during these years. These contributed to setting new work and production records, responding positively to a tight-scheduled work programme.

An RCC-laying World Record was set between December 11 and 12, 2014. In just 24 hours, the continuous maximum production volume equalled 18,519 m3. By June 2015, six million cubic meters of RCC had already been laid and one billion cubic meters of water had collected in the reservoir formed by the dam.

In 2015 alone, the work carried out by Salini Impregilo as part of the Gibe III project contributed to the growth of the country, accounting for 0.4% of GDP and income distributed to households, 0.28% of tax revenue and 0.13% in terms of total employment[1].

 

SALINI IMPREGILO’S FOOTPRINT

 

 

The project not only contributes to the country as a whole, but also offers benefits for local communities, as it regulates the water flow and prevents the recurrence of the floods that used to have a devastating effect on the inhabitants of the valley. In addition, the creation of the reservoir enables the development of fisheries, diversifying not only the local economy but also the diet of local people, with positive effects on their health.

The project also preserves the traditional recess agriculture practised by some of the Lower Omo Valley communities, more than 300 km downstream from Gibe III. Even though this system does not provide sufficient food for local populations, the social and environmental impact assessments carried out by the customer for the project revealed the risk of stopping floods by building the dam. To mitigate this potential impact, Salini Impregilo has supported the customer with the development of special run-offs from the dam that are the right size to recreate the periodic flooding of the river but in a controlled and non-destructive way. In 2015 the run-offs were handed over to EEP, which is responsible for managing them, and they were successfully put into operation in 2016.

 

[1] Figures from a study conducted by the company with methodological oversight by KPMG Italia.

 

GIBE III: AN ENERGY SOURCE FOR ETHIOPIA

Gibe III's impact on Ethiopia's energy production is decisive. It will increase Ethiopia's energy production by 85% and will greatly contribute to the country's development process, making it a regional reference point for energy production and distribution.

Gibe III, besides producing power to meet the internal energy demand, will allow 50% of the energy produced to be sold abroad, in countries like Kenya, Sudan and Djibuti, therefore confirming Ethiopia's desire to become Africa's energy hub.

 

MAIN MILESTONES

JULY 2006
Contract Signature
JANUARY 2009
River Diversion
JANUARY 2015
Start of Impounding
OCTOBER 2015
Start of Energy Generation
DECEMBER2016
Inauguration

MAIN FEATURES:

Dam

Height: 250 m
Crest length: 630 m
Excavation: 4,000,000 m3
Roller Compacted Concrete: 6,114,000 m3

Powerhouse

Size: 234 x 37 x 43
Turbines: 10 Francis turbines with a capacity of 187 MW each

Power & Energy

Installed power: 1,870 MW
Generation capacity: 6,500 GWh/year

Reservoir

Surface Area 200 km2
Storage Capacity 14,000 x 106 m3

River diversion

2 x Cofferdams (Embankment) Upstream height 55 m, Downstream height 19 m
3 x diversion tunnels, total length 3,218 m

MEDIA

1712/16

Ethiopia inaugurates tallest RCC dam in world built by Salini Impregilo

Ethiopia has inaugurated Gibe III, the biggest hydroelectric dam in the country with an installed capacity of 1,870 MW and the tallest of its kind in the world. Built by Salini Impregilo, it will almost double the eastern African country’s electricity production as it strives to modernize its economy and become a regional energy hub.