INGENIEUR
Area
Kuching & Kota
Samarahan Division
Sri Aman Division
Rajang Catchment
Rajang to Baram
Baram Catchment
Limbang Division
Land Surface
Area
x 103 km2
9.0
Gross Surface Hydropower Potential
% Total
Total Potential
Density
TWh/a
GWh/km2
3.3
0.37
1.7
10.7
50.8
24.2
22.2
8.3
3.6
104.9
6.5
60.8
12.9
0.34
2.06
0.27
2.74
1.55
1.9
54.6
3.4
31.7
6.7
Table 1: Hydropower Potential Distribution in Sarawak
T
he first preliminary survey on the estimation
of the gross hydropower potential of Sarawak
was undertaken in 1962 by the Snowy
Mountains Hydro-Electric Authority of Australia
(SMEHA) under the Colombo Plan aid programme.
The study by SMEHA indicated that the gross
hydropower potential is about 192 TWh per
annum with 86% of the gross potential in Rajang
and Baram catchments as shown in Table 1. The
study was primarily limited to the assessment
of hydropower potential available in the State
and identification of potential sites which could be
economically developed for power generation.
In 1979, a more detailed and comprehensive
study known as the Master Plan for Power System
Development was initiated with the main emphasis
on the hydropower potential. This Master Plan for
Power System Development was completed in
1981 and was carried out jointly by a project team
from the Sarawak Electricity Supply Corporation
(SESCO), now a subsidiary company under
Sarawak Energy Berhad (SEB), and a group
of West German and Swiss consultants, known
as the SAMA Consortium. The consortium was
sponsored under a Technical Aid Programme
extended to Malaysia by the German Technical
Co-operation Ltd. (GTZ) on behalf of the
Government of the Federal Republic of Germany.
The general procedure adopted in the survey
started with a desktop study of all available
topographical, hydrological and geological
information to identity potential dam sites. Each
river was considered as a whole and the
study went into necessary details to determine
the power output and other relevant physical
features of each site. The basic criterion was
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to maximise the natural head from the source
to the mouth of the river, taking into account the
possibility of inter-basin water transfer.
After the desktop study, a field
reconnaissance of the identified dam sites
was undertaken. Project layouts were adjusted
to actual field information based on site
topography and geology. Subsequently, water
management computations were carried out and
cost estimates prepared.
A subsequent evaluation of the optimum
development chains for all the river basins
was carried out to determine the best means of
harnessing their respective hydropower potentials.
According to the ‘Master Plan for Power System
Development’, a total of 52 projects could be
developed with a potential of 20,000MW and
energy output of some 87,000GWh/year based on
a plant factor of 0.5. A summary of the results
of the evaluation and optimisation exercises is
given in Table 2.
CURRENT DEVELOPMENT STATUS
To date, three large hydropower projects, Batang
Ai, Bakun and Murum have been completed in
Sarawak. The Batang Ai plant (see Figure 1) began
full operation in 1986 with an installed capacity
of 108MW and annual energy of 620GWh per
year; Bakun (see