Malaysia is focusing on development of its significant small hydropower potential, with a goal of adding 490 MW by 2020 to increase renewable energy generation in the country.
By Samizee Abdullah, Engku Ahmad Azrulhisham, Mohd Juhari Mat Basri and Jamel Othman
The threats of climate change caused by burning fossil fuels and escalating fossil fuel prices make the further rapid development of renewable energy sources a global imperative. Hydropower, as the largest clean and renewable energy source, has played an essential role in the global energy mix. Energy provided by small hydropower is considered a renewable alternative that meets the need to reduce dependence on fossil fuels while substantially reducing greenhouse gas emissions. Furthermore, small hydropower is considered one of the most cost effective and environmental friendly energy generation technologies.
Most small hydropower systems are run-of-river schemes, which do not require large storage reservoirs. Power generation from run-of-river plants is free of CO2 emissions and this is one of the oldest environmentally friendly technologies. The potential of small hydropower projects in Malaysia is huge, providing a total generating capacity of about 500 MW for the long run, especially in the run-of-river types.
|This photo shows the intake house for the 6 MW Sungai Perting Mini Hydro Power Station in Malaysia.|
Malaysia’s installed electricity generating capacity was 26,063 MW in 2013, consisting of 21,628 MW in Peninsular Malaysia, 1,303 MW in Sabah and 3,132 MW in Sarawak. Gas and coal remained the most-used fuels for power generation at 47.99% and 25.73%, respectively, followed by hydroelectric at 14.73% and biomass at 2.97%. Meanwhile, mini hydro (see below for definition) contributed 0.17%. In terms of electricity growth, maximum demand of 16,562 MW as recorded on May 13, 2013, surpassing the initial target of 16,324 MW by 1.5%.1
Categorizing small hydro
There is no globally accepted definition of small hydropower. The criterion currently used is capacity, and the definition varies by country. In Malaysia, small hydropower refers to run-of-river schemes up to 30 MW in capacity.2 Small hydropower usually is broken down into three sizes: full scale, mini and micro.3 A full scale small hydropower scheme has a capacity of more than 10 MW, which is enough electricity for large areas and extensive grid supplies (up to 30 MW). Mini hydro schemes make a smaller contribution to national grid supplies, typically in the range of 500 kW to 10 MW. Micro hydro schemes usually range from 5 kW to 500 kW, do not supply the national grid and produce just enough power to provide domestic lighting to a group of houses through charging a battery.
Small hydropower can offer more opportunity to support rural electrification expansion and also contribute to energy and capacity support of the grid. The potential for small hydro in Malaysia is huge, but the energy available from the rivers already contributes significantly to electricity supply in rural areas. One example of a successful small hydro project in Malaysia is Perting Mini Hydropower plant at Bentong, Pahang (see photo above and at left). It is a run-of-river scheme that began operating in 2009 with a capacity of 4.2 MW and net export capacity of 4 MW to the Tenaga Nasional Berhad power station. This plant is owned by Amcorp Pertin Hydro Sdn. Bhd. and was upgraded to 6 MW in 2015. It attained global recognition by receiving the ASEAN Energy Award in 2012 and the Association of Consulting Engineers Malaysia’s Silver Award of Merit 2013 in the field of Renewable Energy.
Power from water
For purposes of our assessment, we used the below “definition” of a small hydro facility: It is a run-of-river scheme that does not stop the river flow but partially diverts it by means of an intake weir. A settling basin in front of the weir removes sand particles from the water and then a channel leads the water into a forebay. Finally, the penstock delivers the water to the powerhouse, where it runs through a turbine and is discharged back into the river downstream. A small hydropower system requires both adequate water flow and a change in altitude.
As is known, power available from a hydropower scheme is related to the vertical height the water falls (head) and the flow rate through the turbine.
But there are several factors that affect the overall efficiency of small hydropower systems. The overall efficiency of power generated depends on the overall losses of the system, which is calculated by considering the losses at the channel, penstock, turbine, generator and transmission.
Issues and challenges
The population of Malaysia is more than 30 million and the country has a total area of 329,847 km2. The climate of the country features high humidity and copious rainfall. Daytime temperature rise above 30 degrees Celsius year-round and night-time temperatures rarely drop below 20 C. The average rainfall is 2,500 mm for Peninsular Malaysia and 5,080 mm for East Malaysia.
With its hills and mountains in the interior, Malaysia is blessed with abundant streams and rivers flowing from the highlands, and 149 sites for small hydropower installation have been identified through reconnaissance studies carried out in 2010, with estimated capacity of 28.9 MW.4 Malaysia has utilized its hydro potential mainly in the range of large hydropower, with about 5,456 MW installed.5 In 2012, the government expressed a goal that the energy provided by small hydro schemes be increased substantially, from 60 MW in 2011 to 490 MW by 2020.6 Small hydropower development is in line with the country’s Small Renewable Energy Programme (SREP), which encourages the development of electricity generation from renewable sources. In the SREP, owners of small renewable energy plants can apply to sell the electricity to the national utility through the Distribution Grid System.
The adoption of small hydropower has been making progress in Malaysia, and this has been spurred on by the Renewable Energy (RE) Act 2011, which was approved by the parliament in April 2011. As a result of this law, a feed-in tariff (FiT) scheme was adopted in December 2011. Under the FiT scheme, small power generation plants that use RE can apply to sell electricity to the utility through the distribution grid system owned by the national utility company Tenaga Nasional Berhad (TNB) through the RE Power Purchase Agreement (REPPA).7 As of May 2016, installed capacity of small hydro under the country’s FiT program reached 18.30 MW, and the plants in progress equal 255.84 MW.8
|This photo shows the weir structure for the same small hydro facility.|
There are several issues and challenges that affect the development of small hydropower in Malaysia. The lack of field expertise and technical skills is the largest barrier impeding this development, and also the financial institutions are unfamiliar with assessing risks for small hydropower projects.9 Malaysia also appears to be facing a number of specific challenges in developing small hydropower, including heavy rainfall causing flooding and overflow, inefficient designs to filter out sand and debris before it enters the turbine, complicated regulatory requirements in terms of land acquisition and environmental impact assessment, and risk of water pollution during construction work resulting from logging activities.8 In addition, the access to land and water is subject to federal and state regulation.
The hydrological parameters are also an important factor contributing to the success of small hydropower projects. Any run-of-river scheme has the same major constraint: the amount of water available varies from season to season. There are challenges in determining the feasibility of a small hydro scheme due to the risk of water scarcity and unexpected water flows resulting from dry seasons, climate change and river pollution.2 Furthermore, the performance of small hydropower is influenced by sedimentation, which reduces the overall efficiency of the power generation system. There is a need to have detailed research on sedimentation, such as how to better solve sediment problems and facilitate sediment handling in small hydro systems. The Sustainable Energy Analysis Laboratory at the Universiti Kuala Lumpur is currently involved in the KeTTHA (Ministry of Energy, Green Technology and Water) funded research project on development of an empirical sediment settling prediction system and optimization tools for small hydropower plants.
Small hydropower is a good alternative to conventional electricity generation, especially to provide considerable electricity in rural areas. With its hilly topography and an abundant number of streams flowing to foothills, Malaysia offers many potential sites for run-of-river small hydropower.
Despite the positive benefits from small hydropower plants, there are issues and challenges that need to be considered for the success of the project. The research and innovation in developing small hydropower is very encouraging, which is providing many benefits in terms of design, cost effectiveness and the installation process.
This article presents portions of a research project on “Parametric Distribution Approach for Flow Duration Curve Approximation and Potential Analysis of Small Hydro System,” which is supported by AMCORP Perting Hydro Sdn. Bhd. This project is partly funded by the Ministry of Energy, Green Technology and Water under KeTTHA / AAIBE Research Grant 02-1-56-1565.
1. ”Performance and Statistical Information on Electricity Supply Industry in Malaysia,” Energy Commission Malaysia, 2013, www.st.gov.my.
2. “Malaysia Report on Small Hydro Power,” National Foresight Institute, 2012, www.myforesight.my.
3. Harvey, A., et al, “Micro-Hydro Design Manual: A Guide to Small-scale Water Power Schemes,” Practical Action Publishing, Rugby, Warwickshire, United Kingdom, 1993.
4. Hussein, I., and N. Raman, “Reconnaissance Studies of Micro Hydro Potential in Malaysia,” International Conference on Energy and Sustainable Development: Issues and Strategies, Asian Institute of Technology, Pathumthani, Thailand, 2010.
5. Malaysia-Green Energy Lighting in Future, www.andritz.com.
6. “Current Status and Development Plan for Small Hydro Power in Malaysia,” APEC Energy Working Group, 2013, www.egnret.ewg.apec.org.
7. Nasab, Amir Pasha Zanjani, “Financial Analysis of Small-Hydro Power Project in Malaysia from the Investor Perspective,” 2012, www.ipcbee.com/vol33/030-ICEE2012-B10031.pdf.
8. Sustainable Energy Development Authority of Malaysia, www.seda.gov.my.
9. “World Small Hydropower Development Report 2013,” www.smallhydroworld.org.
Samizee Abdullah is senior lecturer, Engku Ahmad Azrulhisham is associate professor, Mohd Juhari Mat Basri is lecturer and Jamel Othman is associate professor at the Sustainable Energy Analysis Laboratory at the Universiti Kuala Lumpur Malaysia France Institute in Malaysia.