POWER September 2020 - 24

TOP PLANT
Award-Winning Hydropower
Project Helps Electrify Ethiopia
Courtesy: Stantec
The government of Ethiopia has set a goal of providing access to electricity
to all its citizens by 2025. It still has a long way to go, but projects such as
the Genale Dawa III hydropower station are helping it get closer to the target.
That's one of the reasons Genale Dawa III is a POWER Top Plant.
Aaron Larson
he population in Africa is among the
fastest growing and youngest in the
world. The International Energy Agency
(IEA) has reported that 1-in-2 people added
to the world population between today
and 2040 will be in Africa. The continent is
expected to overtake China and India, and
become the world's most populous region
by 2023. By some estimates, more than
half a billion people are expected to be
added to Africa's urban population by 2040.
Let's take a moment to digest that.
T
New York City, which includes the boroughs
of Brooklyn, Queens, Manhattan,
the Bronx, and Staten Island, is the most
populous city in the U.S. Its population
was estimated to be 8,336,817 in 2019.
That basically means, on average, three
cities the size of New York City will be
added to Africa every year from now
through 2040. Of course, those people
will ultimately be added in a less-conspicuous
manner in many cities throughout
the continent rather than in new cities
the size of NYC, but the magnitude of
the population growth is mindboggling.
Why that's important to the power industry
is because growing urban populations
mean growing energy demand.
According to IEA data, more than 510
million people in sub-Saharan Africa still
do not have access to electricity today.
Despite progress in some countries,
current and planned efforts to provide
access to modern energy services have
24
barely outpaced population growth.
Ethiopia is a case in point. More than
50 million people in Ethiopia, population
110 million, lack access to electricity. Still,
it was cited by the IEA as one country that
has made progress. While actively pursuing
rural electrification for years, Ethiopia
officially launched its National Electrification
Program in November 2017, which aims to
achieve 100% electrification by 2025. Significant
generating capacity additions will
be needed to help reach that goal. The IEA
reported about 1 GW of geothermal and
2 GW of wind energy are expected to be
added by 2030, but the key component of
the electrification effort revolves around
hydropower. About 22 GW of hydro is expected
to be added in the next 10 years.
Genale Dawa III
The Genale Dawa III (GD-3) hydropower
project, located in southern Ethiopia on
the Dawa River, some 630 kilometers
(km) from the capital Addis Abada, is one
piece of the puzzle. The project is owned
and operated by Ethiopian Electrical Power
(EEP). Stantec provided engineering,
procurement, and construction (EPC) contract
management consultancy services.
GD-3 has an installed capacity of 254
MW (Figure 1). Three vertical Francis
turbine generators, each with a generating
capacity of 84.7 MW, are housed in
one large underground cavern, while the
transformers are housed in an adjacent
one, with power cables extending to an
www.powermag.com
1. The Genale Dawa III powerhouse has
three units with a combined capacity of 254
MW. Courtesy: Stantec
external switchyard via an inclined tunnel.
The concrete-faced rock-fill dam (CFRD)
is 110 meters (m) high with a crest length
of 456 m. Rockfill volume is some 3.22
million m3. The gated spillway comprises
an ogee section leading to a 250-m-long
chute ending in a flip bucket, designed for
a maximum discharge of 1,880 m3/second.
Three radial gates-6 m wide by 9.065 m
high-were installed to maintain the reservoir
level at an elevation of 1,120 m above
sea level and release large floods when
they occur, most years.
During construction of the dam, a diversion
tunnel handled river flows. It was
500 m long, 9 m high by 7 m wide, designed
to accommodate flows of up to
813 m3/second under a head of 94 m.
A 60-m-high power intake structure
was constructed on the left bank of the
river about 600 m upstream of the dam.
It includes one large vertical sliding gate
POWER | September 2020
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POWER September 2020

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