Harnessing hydropower in Malaysia

7 December 2020

Malaysia has relatively abundant hydropower resources, albeit unevenly distributed among the different parts of the country, with heavier concentrations in Sabah and Sarawak. The first major hydropower dam, the Chenderoh Dam (27MW), was constructed in 1930. In the decades that followed, systematic development of the country’s natural resources has contributed over 27,300GWh of energy annually from an overall installed capacity of 6240MW. This represents about 17% of total generation capacity (34,200MW) in the country, including gas, solar, coal and other power sources. Report by Zainal Abidin Othman, Director and Chairman of SMEC (Malaysia) Sdn Berhad

Malaysia has a total land mass of about 330,000km2 with mean elevation of about 300m. The average rainfall is slightly more than 2600mm per year. In the mid-1970’s an inventory survey of hydropower resources of the country was conducted and has since been used as indicative information of available hydropower resources within the country. Overall, the total gross hydropower potential documented is about 414,000GWh per year of which about 123,000GWh per year is the technical potential for development. About 87,000 GWh (70%) of this energy potential is located in Sarawak, 20,000 GWh in Sabah and 16,000 GWh in Peninsular Malaysia.

The development of major hydropower projects in Malaysia is generally undertaken by the utility companies such as Tenaga Nasional Berhad (TNB) in Peninsular Malaysia, Sarawak Energy Berhad (SEB) in Sarawak while in Sabah by the Sabah Electricity Sdn Bhd (SESB). There have been attempts by private players to participate in the development of major hydropower in Malaysia but with very little success to date. The development of smaller hydropower projects below 30MW is open to private parties and incentivized by the Feed-in Tariff (FiT) mechanism managed by the Government.

Decades of development 

Early initiatives in the 1960’s to 1980’s 

During the period up to the 1960’s, the Cameron Highlands Hydropower Scheme was developed comprising the major Cameron Highlands (105MW) and Batang Padang (154MW) projects. The scheme involves small but steep mountain streams where the river flows were diverted via long tunnels. The major developments are pondage projects with relatively small dams and limited reservoir storages, whilst the smaller ones are all run-of -river projects. 

The concept of maximum resource utilization in the energy sector was adopted by the country in the 1970’s and saw the development of more major hydro projects in the Perak and Terengganu river basins. 

Along the upper reaches of the Perak river, a cascade of three dam hydropower projects was constructed and the first of these projects was Temengor (348MW), a zoned processed rockfill dam constructed between 1974 to 1978. The Bersia dam project (72MW) located immediately downstream of Temengor was constructed between 1980 to 1983. Bersia is a concrete gravity dam with four gated spillway bays. The third, Kenering dam project (120MW), located further downstream of Bersia was constructed during the same period. Kenering is also a concrete gravity dam with six gated spillway bays. 

Apart from power generation the cascade schemes also provide a measurable degree of flood mitigation.

Concurrently, the Kenyir Dam project (400MW) was being developed in the Terengganu river basin. The Kenyir Dam is a 155m high rockfill dam with eight earthfill saddle dams forming a reservoir surface area of 370km2. The ungated chute spillway has a discharge capacity of 7000m3/sec. This is the largest dam in Peninsular Malaysia and provides significant flood mitigation in addition to power generation.

The first major hydropower development in Sarawak was the Batang Ai project constructed between 1981 to 1985. The project comprises an 85m high concrete faced rockfill dam and three saddle dams with a reservoir surface area of 85km2. The Lima saddle dam is similar in construction as the main dam while the other two saddle dams Bekatan and Sebangi are of the earthfill type. The gated spillway of the main dam is capable of discharging 2600m3/sec.

The Kenyir Dam project in the Terengganu river basin. The dam is a 155m high rockfill dam with eight earthfill saddle dams forming a reservoir surface area of 370km2

Bigger and better – reemergence of hydropower projects in the 1990’s

In the late 1980s up to the early 1990s, many projects around the world, including in Malaysia, were paused due to a number of factors including global financial constraints and concerns over the environmental and social impacts of hydropower development.

It was not until 1991 that the next major hydropower project emerged. The Pergau project (600MW) comprises a 75m high earthfill dam with ungated chute spillway with a discharge capacity of 2470m3/sec, a complex 24km system of tunnels and a underground power station. In addition to the inflow from the Pergau river, water is also diverted into the reservoir through the tunnel with six gravity intakes over the 24km length. 

Next came the massive 2400MW Bakun project in Sarawak, which after some years of difficulty was undertaken through a contract with a Malaysia China Joint Venture for the civil works. Amidst significant commercial, technical and socio-environmental issues faced during construction, the project was finally commissioned in 2011. 

Having identified hydropower as a key catalyst to drive and accelerate socio-economic growth in the state, Sarawak continued building large hydropower projects, including the Murum hydropower project (944MW).  Meanwhile in the Peninsular, it was more than a decade before any development of new major hydro projects resumed. The Hulu Terengganu project started construction in 2010 followed by the Ulu Jelai Hydroelectric project a year later in 2011.

The Hulu Terengganu project (265MW) was commissioned in 2015 comprising two cascading schemes, the 75m high Puah earthfill dam (250MW) with three gated spillways and an underground power station, and the 36m high Tembat concrete dam (15MW) with a free overflow spillway and a surface power station. SMEC carried out the feasibility study and tender design for the Project.  

The Ulu Jelai hydro project (372MW), for which SMEC carried out detailed design, construction supervision and contract management, was commissioned in 2016 comprising an 88m high roller compacted concrete dam, spillway discharge capacity of 2300m3/sec and an underground power station. 

Economic drivers beyond power generation 

In addition to power generation and flood mitigation, these major projects have significantly contributed to the economic development of the country. Some have become tourist attractions especially for those interested in outdoor water sports and eco-tourism. Kenyir dam in Terengganu has established recreational activities using the reservoir and there are many resorts on its shores as well as boat houses. Fishing is popular, as are jungle trekking, waterfalls and caves. Kayaking, canoeing, boating, rafting and rapids shooting are among the many water sport activities available for visitors. Arguably Kenyir Lake’s most iconic attraction is a fish sanctuary breeding and nursery ground for Mahseer (kelah), a freshwater gamefish. 

A similar setting is also available at the Temengor dam reservoir focused on eco-tourism. The lake is also the gateway to the Royal Belum State Park (RBSP), one of the oldest rainforests in the world, dating back over 130 million years. The area is also notable for harbouring high concentrations of at least three different Rafflesia species. An eco-friendly aquaculture facility has also been developed since 2008 within an industrial aquaculture zone in the lake. 

The Ulu Jelai project was commissioned in 2016

Prospective hydropower projects

Since 2004, SMEC has assisted TNB with evaluating and ranking several hydropower projects in Peninsular Malaysia. A number of prospective hydropower projects, including storage projects and run-of-river projects, were evaluated. Since then, five of the top ranked storage projects – namely Hulu Terengganu, Tekai, Ulu Jelai, Telom and Nenggiri –have moved on to the next stage of development as further described below.

The Telom hydropower project was at a pre-feasibility development stage and was then upgraded to feasibility stage in 2014. The project comprises a concrete faced rockfill dam, a 132MW surface power station located at the toe of the dam, ten saddle dams of varying height up to 40m, an ungated ogee spillway, a tunnel that transfers water from Jelai Kecil river and a re-regulating weir about 5 km downstream of the main dam. The project was expected to move to the next development stage, but a number of issues caused the project to be shelved in 2018.

As described above the Hulu Terengganu and Ulu Jelai projects were commissioned in 2015 and 2016 respectively. Detailed investigations and tender design for the Tekai Project (168MW) have been completed. 

The Nenggiri Project (300MW) design has been completed and the project is progressing to the next development stage. The project comprises a RCC dam with gated radial spillway, a saddle dam, a re-regulating dam and a surface power station. The reservoir created will inundate approximately an area of 50km2. 

In the near term, given the focus on enhancing renewable energy generation, projects such as run-of- river and, to some extent, pumped storage hydro projects will make an inroad into the market. In early 2020, the Sustainable Energy Development Authority (SEDA) awarded contracts to 15 bidders for mini-hydro development with a total installed capacity of 176MW. These projects are expected to start commercial operations in late 2025.

The only major hydro project under construction currently in Sarawak is the Baleh project (1285MW). The project comprises a concrete faced rockfill dam 188m high, a radial gated spillway capable of discharging a design flood of 20,000m3/sec and a surface power station housing 5 turbines. Construction is scheduled to be completed in 2026.

Other major hydro projects in the pipeline in Sarawak are Limbang 2 (130MW), Belaga (160MW), Linau (182MW), Trusan 2 (240MW), Baram 3 (300MW) and Pelagus (465MW) totaling 1477MW. These are among the major projects that will ensure that the state achieves its target of generating 7400MW by 2025. 

Meanwhile in Sabah, two major hydropower projects have been identified: The Upper Padas project, comprising a 120m high RCC dam across the Padas river near Kuala Tomani, and the Liwagu project (165MW). Both have been in the development stage for some time, but a construction start date is yet to be confirmed.

Lessons for owners, developers and consultants 

Quantitative risk analysis 

It was observed that in some of the major complex projects the risk management was limited to qualitative expert judgement and subjective analysis to rank a risk event. This usually minimizes uncertainty and highlights priority risks but very seldom leads to carrying out a quantitative risk analysis. In the future, the introduction of quantitative risk assessment may be useful at several stages throughout the lifecycle of any major, complex project. 

Among the recent major projects, it was also noticed that contractors took a very contractual approach to work that forced developers and their project team to increase contract and claims management personnel to deal with claims and commercial management in a timely and proactive manner. 

Future projects may have to allow provisional sums in the project budget for such a team to be mobilized at short notice whenever needed, as well as suitable budget for technical specialists to be called in whenever claims need to be assessed. It is prudent to select appropriate resources and allow adequate provisional budget based on a quantitative assessment of risks to prepare for such scenarios.

Environmental Impact Assessment 

An important and mandatory element of the Environmental Impact Assessment (EIA) is the Erosion and Sedimentation Control Plan (ESCP). In most instances, however, actual data such as soil data and engineering design with earthworks drawings are not available or inadequate until later stages of the project. 

The ESCP should only commence when the necessary information can be made available, albeit at different stages. The concept, tender and detailed engineering design will have to be in progress or completed in order to furnish the required information to prepare an ESCP. In this manner it will minimise rework and delays in submission for approval by the authorities.

Another challenge in preparing the ESCP is often a lack of understanding by the project design team on the requirements and scope of the ESCP. The project management team should seek advice or feedback from the Consultant (usually a separate entity) on the current scope and associated data and information requirements of the ESCP. This will enable them to be well prepared ahead of the actual ESCP commencement to avoid being caught in a quandary where required information is lacking.  

Putting together the right team

As highlighted above, collaboration among cross-functional teams and robust project management are critical to the success of hydropower projects. SMEC has over 50 years’ experience in the sector and we have invested in building capability and teams with the required technical leadership but also knowledge of local context, challenges and conditions. While as engineers and technical specialists we work to relatively uniform standards and criteria, every project environment presents its own unique issues, and therefore we have found it immensely valuable to invest in and develop on-the-ground teams – at times aided by international specialists – who can contribute to delivering fit for purpose solutions. 

The role of hydropower in Malaysia’s future 

Malaysia has set a target to generate at least 20% of its energy through renewable sources by 2025, and a projection of 41% by 2050. This target is achievable if more Malaysians are committed to using renewable energy. In order to better integrate renewable energy into the current power supply system, the concept of a smart grid is essential. Smart grids are the key enabler for energy security and integration of renewable energy resources. Therefore, future and existing hydro power plants must enhance their capabilities to realise high efficiencies, enhance performance with suitable technology innovation and explore low-cost financing in order to support the penetration and integration of variable renewable generation resources in the power systems.

There have been no known in-depth studies carried out specifically on major hydropower within the renewable sources of solar, biomass, biogas and small hydro energy. This presents an opportunity to explore suitable enhancement technology for major hydropower projects as well as the suitability of pumped storage hydro within the power systems. Professional services firms play an important role in the planning, design, delivery and maintenance of the major hydro and dam infrastructure in Malaysia. SMEC has contributed to major and small hydropower projects in the country which have supported industrial growth since the 1970s. The increase in reliable and affordable power generated by these projects has a significantly positive impact on communities and economic activity, often serving as a catalyst for tourism and other industries. Road relocation due to new reservoirs and provision of access roads into otherwise remote areas offers the opportunity to upgrade communications and open up new areas for economic or tourism development. Access through water navigation is also effective in this respect. 

Currently, only small hydropower plants are considered renewable energy, and effort must be increased to engage policy stakeholders in acknowledging that even major hydropower schemes offer a clean, affordable and secure energy source. Hydropower contributes significantly to the reduction of GHG emissions and to the security of the energy supply. Its development requires relatively high initial investment but is offset by a long lifespan with very low operation and maintenance costs. In addition, hydropower offers one of the best conversion efficiencies of all known energy sources.


Based on the current generation development plan, the major hydropower resources in Peninsular Malaysia could be fully harnessed within the next decade. Moving forward, it is conceivable that development will shift to low head schemes constructed in the lower reaches of major rivers. Subject to the penetration of non-hydro renewable resources into the power system, there is also potential for hydro pumped storage projects.

In the States of Sabah and Sarawak, there is still abundant and undeveloped hydropower potential.  Sarawak has large promising sites to be developed, and with proper planning and political support it can become an exporter of energy to Sabah, Brunei and Kalimantan and the Peninsula via the power transfer cable project. This will also contribute to initiating the formation of the ASEAN power grid to facilitate power transfer between ASEAN countries. 



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