Ghana's enthusiastic quest to become the West African energy
powerhouse has seen a major boost following the commissioning of the 400
megawatts (MW) Bui Hydroelectric Dam in the Tain District of the Brong
Ahafo Region .
The project, which cost over $622 million , is funded
with a concessional loan of $263.5 million and a buyer's credit of
US$298.5 million from the government of the People's Republic of China
and the Exim Bank respectively, with the Government of Ghana
contributing $60 million . The commissioning comes off, following the
completion of the third and final generating unit of the Bui
Hydroelectric Project . The first unit of the Project, which provided
about 133 megawatts of power, was inaugurated in May, to augment energy
supply in the country.
After dry and wet tests, which were to verify
proper, complete and satisfactory erection of the entire sub systems
were successfully carried out, the three generating units, which have
the capacity to generate 133MW each, were commissioned in May, July and
November 2013 . The substantial completion of the Project now, provides
Ghana with additional 400MW (20% increment) of installed capacity, with
average annual generation of 1000GWh. Meanwhile, other associated and
non-power works on the Project including the Bui City will continue till
the second quarter of 2014, when all works on the Project would be
completed. The city is expected to have resorts, hotels, water sports
facilities and diverse other recreational centres for both domestic and
international tourists.
Ghana is on course to achieve the targeted power
generation capacity of 5000 megawatts by 2016, the President John
Dramani Mahama , said at the commissioning of the final phase Bui Dam .
Mr. Mahama , who was joined by the former President John Agyekum Kufuor ,
Chinese Ambassador to Ghana , Ministers of State, senior officials of
the Sinohydro Corporation Limited , chiefs and people of the area to
commission the power facility, noted that; "the project comes at the
time when the Ghanaian economy is growing at 7-8% of gross domestic
product (GDP). So, the demand for energy in the country is therefore
increasing". The Chief Executive Officer of the Bui Power Authority ,
Jabesh Amissah-Arthur said the Bui City project, the luxury aspect of
the just-completed 400 megawatts dam, could be realized if private
investors come onboard. Geologist discovered the dam The Bui
hydro-electric dam had first been envisaged in 1925 by the
British-Australian geologist and naturalist Albert Ernest Kitson when he
visited the Bui Gorge .
The dam had been on the drawing board since the
1960s, when Ghana's largest dam, the Akosombo Dam , was built further
downstream on the Volta River . By 1978 planning for the Bui Dam was
advanced with support from Australia and the World Bank . However, four
military coups stalled the plans. At the time Ghana began to be plagued
by energy rationing, which has persisted since then. In 1992, the
project was revived and a first feasibility study was conducted by the
French firm, Coyne et Bellier. The three-turbine Dam is nestled in a
gorge separating the Bono Ahafo Region from the Northern Region of Ghana
. Ghana entered into an engineering procurement and construction
turnkey project contract for the implementation of the project in April
2007 , with Sinohydro Corporation Limited , a major Chinese dam
construction firm, as the contractor.
The role of the employer was
subsequently assigned to the Bui Power Authority (BPA) to manage and
supervise the project, with the assistance of an engineering consultant,
Coyne et Bellier. On August 24, 2007 , the sod was cut for the
commencement of the project, which has been divided into two phases. Dam
design The Bui Dam is a gravity roller-compacted concrete-type with a
height of 108 m above foundation and 90 m above the riverbed. The crest
of the dam is 492 m long and sits at an elevation of 185 m above sea
level (ASL). The main dam's structural volume is 1,000,000 m3. Southwest
of the dam two saddle (or auxiliary) dams maintain pool levels and
prevent spillage into other areas of the basin. The first and closest to
the main dam is Saddle Dam 1. It is 500 m southwest of the main dam and
is a rock-fill embankment dam.
The dam rises 37 m above ground level
and has a crest length of 300 m.1 km southwest of the main dam is Saddle
Dam 2. This dam is a zoned earth-fill type with a height of 7 m ASL and
a crest length of 580 m (1,903 ft). Both saddle dams have a crest
elevation of 187 m (614 ft) ASL. The reservoir that the main and saddle
dams create will have a maximum capacity of 12,570,000,000 m3 of which
7,720,000,000 m3 is useful for power generation and irrigation. The
reservoir's maximum operating level is 185 m ASL and the minimum 167 m
ASL. At the maximum level, the reservoir will have a surface area of 440
km2 (170 sq mi) while at the minimum it will be 288 km2. The
reservoir's volume at minimum level is 6,600,000,000 m3 .The average
length of the reservoir will be 40 km (25 mi) with an average depth of
29 m (95 ft) and a maximum 88 m (289 ft). Just downstream of the dam on
the left bank is the dam's powerhouse. The intake at the reservoir will
feed water through three penstocks to the three separate 133 MW Francis
turbine-generators.
Each turbine-generator has a step-up transformer to
increase the voltage to transmission level. A fourth unit, with a
penstock on the spillway, will provide four megawatts for station
service and black start power, and will provide minimum flow to maintain
river levels if the main units should be shut down. The power station
will have an installed capacity of 400 MW and an estimated average
annual generation of 980 GWh. The power station's switchyard is located
300 m (984 ft) downstream. Four 161 kV transmission lines connect the
substation to the Ghana grid. The dam's spillway near the right bank
consists of five radial gates, each 15 m wide. The spillway sits at an
elevation of 169 m (554 ft) and has a maximum discharge of 10,450 m3/s
which correlates to a 1-in-10,000 year flood. The dam's outlet works
consist of a single outlet on the right bank converted from one of the
diversion tunnels.
Development of dam Phase one comprises detailed field
investigations and preparatory works needed for the construction of the
main works, while phase two included the construction of the main dam,
the power-house, the spillway and transmission lines. Impoundment of the
dam which commenced in June 2011 continued this year - 2013 with the
completion expected mid this year. Presently the water level is over
169.61 metres above sea level. The Powerhouse Overhead Bridge Crane with
a maximum lifting capacity of 360 tonnes was installed and successfully
tested in May 2012 . At this time, the crane is being used for the
erection of the generating units. The erection of the Turbine-Generator
components (turbine runner, wicket gates, turbine shaft, head cover,
servomotors, generator stator, generator rotor and others) are about
15%, 55%, and 85% complete for Units 1, 2, and 3 respectively.
The
overall progress of the transmission lines is completed while four
electricity transmission lines are constructed to aid in the evacuation
of power from the Bui Generating Plant to the national grid. These four
lines send the power produced from the Plant to the four Ghana Grid
Company Limited ( GridCo ) substations in Sawla, Techiman, Kintampo, and
Sunyani all in Northern and Brong Ahafo regions for distribution to
consumers. The development of the hydro-power scheme on the Black Volta
River at the Bui Gorge becomes the third largest hydro-power dam after
Akosombo and Kpong hydro-power dams in the West African country. The Bui
Hydroelectric Project , which is commissioned, was designed primarily
for hydro-power generation.
It, however, also includes the development
of an irrigation scheme for agricultural development, and it also
presents an opportunity for enhanced eco-tourism and fisheries. It also
includes a Resettlement and Community Support Program, the Chief
Executive Officer of the Bui Power Authority , Jabesh Amissah-Arthu
said. Compensation The Lands Valuation Division of the Lands Commission ,
acting on behalf of the Government of Ghana and with the assistance of
the Bui Power Authority (BPA) has completed the payment of the first
batch of crop compensation to persons whose economy trees and crops have
been affected by the ongoing Bui Hydroelectric construction work.
According to Amissah Arthur, the economy trees and crops for which
payment is currently being made were those located at either the current
construction site, the resettlement sites or within the area to be
inundated by the Bui reservoir. The beneficiaries for this batch of
compensation payments, about 580 people, have since received a total of
$1 million .
"The next batch of compensation payments which is also
being processed cover the economic trees and crops also affected by the
construction of transmission lines and substations as part of the
Project," Arthur said. Work has been completed on all 170 housing units
in the Resettlement Part B Township where the three remaining
communities comprising Bui, Bator-Akanyakrom, and Dokokyina are to be
resettled, Arthur revealed. While 29 households, comprising 156 people
out of a total of 36 households (165 people) from Dokokyina have been
resettled amicable. He disclosed that "Livelihood enhancement programme
to restore lost economic activities and improving living standards in
project affected communities is underway". Under the programme, the
Authority gives US$100 to each person in a household. This will continue
for a year. "In addition, the Authority will build fish ponds for the
settlers.
They can also fish in the downstream of the dam," Arthur said.
Water supply systems (bore holes) are in place. The construction of a
6-unit classroom block for primary school has been completed. Works on
the community centre are 75% completed, while construction of internal
roads is underway. All these facilities will be connected to electricity
with help of the Authority. To add up, construction of 24 replacement
housing units to replace the temporary houses provided earlier for four
communities such as Brewohodi, Lucene, Agbegikuro and Dam Site is
underway. Benefits The project which commissioned today will increase
the installed Ghana's electricity generation capacity which stands at
2,000MW, with a demand of 1,500MW.
Together with three thermal power
plants (Aboadze, Asugli and Tema Thermal 1 Power Plant) will contribute
to alleviate power shortages that are common in Ghana . It will also
reinforce the Transmission Network in the three northern regions
comprising Northern, Upper East and Upper West regions. Furthermore,
like all any hydro-power plants, the project avoids greenhouse gas
emissions that would have occurred if thermal power plants had been
built instead. An additional expected benefit is the irrigation of
high-yield crops on over 30,000 hectares of fertile land in an "
Economic Free Zone ".
"As the country moves to develop its oil and gas
resources, the government is keen not to push agriculture to the
backstage but to continue to improve inputs for sustainable agricultural
growth, food availability for the people of Ghana ," the Minister of
Energy and Petroleum, Emmanuel Armah-Kofi said. He said the government
was therefore taking advantage of the reservoir to be created by the Bui
Hydropower Project to promote the irrigation over 30,000 hectares of
land. The proposed land area is located about 32km of the Dam site.
Crops which will be cultivated on the area include but not limited to
maize, sorghum, yam, cassava, soya bean, pepper, cashew, sugar cane,
cabbage, and vegetables. An agronomist, Philip Abayori explained:
"The
Bui area has large tracts of fertile and irrigable land second only to
the Afram Plains in the Eastern part of Ghana and it is the intention of
government to utilize the land to augment efforts at opening Northern
Ghana for economic growth and development". He was quick to reveal that
the Bui area had been declared an Economic Free Zone to enjoy the same
benefits granted to companies under the Ghana Free Zone Board's regime.
All these are geared towards the creation of thousands of employment
opportunities in the area, according to the CEO, Amissah-Arthur.
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