Kota 2 small hydropower investigation, feasibility and tender design

Client: Sarawak Energy Berhad
Location: Lawas, Sarawak, Malaysia
Date: April 2013 - February 2015

Investigating and designing a small hydropower scheme for cost-effective, reliable and renewable rural electrification in Sarawak, Malaysia

Background

The Malaysian state of Sarawak is keen to accelerate the state’s economic growth and the quality of life of its population by developing new renewable energy resources, particularly in hydropower.  Sarawak Energy Berhad (SEB) planned to develop the Kota 2 hydropower project in the Lawas region of northern Sarawak to displace expensive diesel generation, and help to provide much needed generation capacity.

Without Kota 2, load forecasts indicate that the isolated Lawas power grid, currently supplied by two mini-hydro schemes and a diesel power station, would not be able to meet power demand by 2017.

Solution

SEB engaged Entura to investigate the feasibility of Kota 2, which included Lidar survey, installation of a hydrological monitoring site, and geological mapping of the site.

In 2014, Entura we undertook supplementary investigations and analyses, and developed a preliminary design based on a value engineering process. Tender design drawings and documentation were then prepared for a single EPC contract.

The tender design included access roads, river diversion works during construction, weir and intake, desilting basin, 3.5 km of headrace pipeline, surge tank, penstock, powerhouse to house three turbines with a total installed capacity of 10.5 MW, and all of the specifications for the electrical and mechanical equipment.

Initial construction planning, implementation schedule and cost estimation was undertaken for the project, with a risk based contingency, using a Monte Carlo based method, to allow for the uncertainty.

Outcome

Through Entura’s investigations and analysis, the Kota 2 project has been optimised to maximise its benefits to Sarawak Energy.

The weir site was modified to take into account the geological site conditions and a desilting basin was incorporated into the design to avoid excessive wear due to sediment. Despite the challenging topography in the area, the access road and pipeline alignment were optimised to reduce the cost of earthworks.

Building on our owner-operator experience, we undertook a HAZOP to identify and mitigate any safety issues associated with the future operation and maintenance of the hydropower scheme.

The award of the construction contract for the Kota 2 project is planned for the second quarter of 2015.  Once completed, the energy modelling predicts that the need for diesel generation will be limited to low flow periods only, dramatically reducing the cost of energy production.

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