Small scale hydropower is one of the technology options to generate and supply electricity to grid off and rural applications with almost zero emission. Malaysia is blessed with abundance of water sources and receives high rain volume per year which can be used to generate power. This paper is carried out to present the potential of small scale hydropower in Malaysia and its current status at low head location and rural electrification. Moreover, the relevant research literatures for small scale hydropower technology and the challenges facing by small renewable energy power in Malaysia are also reviewed. The review of available works display that the estimated hydropower resources in Malaysia are registered to be 29,000 MW, of which 500 MW is from small (mini)-hydro power. For this, a total of 149 sites for small hydropower potential have been identified in the country and the expected potential by 2020 is 490 MW. Despite hydro-power technologies are preferable choices for energy generation in Malaysia, they have not been fully exploited yet due to some technical, economical, and institutional challenges. Therefore, this paper can provide information for further investigations on the application of small scale hydropower for rural electrification in Malaysia.

Small Scale Hydro-Power as a Source of Renewable Energy in Malaysia: A Review

A gravitation vortex type water turbine, which mainly comprises a runner and a tank, generates electricity by introducing a flow of water into the tank and using the gravitation vortex generated when the water drains from the bottom of the tank. This water turbine is capable of generating electricity using a low head and a low flow rate with relatively simple structure. However, because its flow field has a free surface, this water turbine is extremely complicated, and thus its relevance to performance for the generation of electricity has not been clarified. This study aims to clarify the performance and flow field of a gravitation vortex type water turbine. We conducted experiments and numerical analysis, taking the free surface into consideration. As a result, the experimental and computational values of the torque, turbine output, turbine efficiency, and effective head agreed with one another. The performance of this water turbine can be predicted by this analysis. It has been shown that when the rotational speed increases at the runner inlet, the forward flow area expands. However, when the air area decreases, the backward flow area also expands.

/pdf/performance-and-flow-field-of-a-gravitation-vortex-type-5f5l8mpaac.pdf

Performance and Flow Field of a Gravitation Vortex Type Water Turbine

Small-scale hydroelectric power generation has recently attracted considerable attention. The authors previously proposed an undershot cross-flow water turbine with a very low head suitable for application to open channels. The water turbine was of a cross-flow type and could be used in open channels with the undershot method, remarkably simplifying its design by eliminating guide vanes and the casing. The water turbine was fitted with curved blades (such as the runners of a typical cross-flow water turbine) installed in tube channels. However, there was ambiguity as to how the blades’ shape influenced the turbine’s performance and flow field. To resolve this issue, the present study applies straight blades to an undershot cross-flow water turbine and examines the performance and flow field via experiments and numerical analyses. Results reveal that the output power and the turbine efficiency of the Straight Blades runner were greater than those of the Curved Blades runner regardless of the rotational speed. Compared with the Curved Blades runner, the output power and the turbine efficiency of the Straight Blades runner were improved by about 31.7% and about 67.1%, respectively.

/pdf/study-on-an-undershot-cross-flow-water-turbine-with-straight-47znizpl1f.pdf

Study on an Undershot Cross-Flow Water Turbine with Straight Blades

Loss analysis of gravitation vortex type water turbine and influence of flow rate on the turbine’s performance

Current environmental catastrophes generating from fossil fuel power generation has attracted the attention of energy planners to look for sustainable energy sources. Hydropower is one of the oldest energy sources that have been utilized all over the world to generate electricity, especially in remote areas. Being one of the most densely populated countries, the majority of power demand is fulfilled from fossil fuel. Despite having lots of rivers, Bangladesh has not explored its true potential. So, this paper presents a comprehensive review of the current hydropower potential in Bangladesh. Locations having hydropower potential is evaluated. Different technologies used for hydropower generation have been reviewed. Moreover, global hydropower potential has also been discussed in this study. Based on the economic and environmental study, it is found that small scale hydropower is most feasible in Bangladesh to provide sustainable energy. With a reasonable flow rate, 232 rivers of Bangladesh can be utilized small scale hydropower generation as well as ensuring energy security for remote people. The current study is believed to provide useful information in advancing the generation of hydropower based electricity in Bangladesh.

/pdf/an-overview-of-the-hydropower-production-potential-in-4u9w9ob3uv.pdf

An overview of the hydropower production potential in Bangladesh to meet the energy requirements

Erratum: The Flow Field of Undershot Cross-Flow Water Turbines Based on PIV Measurements and Numerical Analysis

Recently, small hydroelectric generators have gained attention as a further development in water turbine technology for ultra low head drops in open channels. The authors have evaluated the application of cross-flow water turbines in open channels as an undershot type after removing the casings and guide vanes to substantially simplify these water turbines. However, because undershot cross-flow water turbines are designed on the basis of cross-flow water turbine runners used in typical pipelines, it remains unclear whether the number of blades has an effect on the performance or flow fields. Thus, in this research, experiments and numerical analyses are employed to study the performance and flow fields of undershot cross-flow water turbines with varying number of blades. The findings show that the turbine output and torque are lower, the fluctuation is significantly higher, and the turbine efficiency is higher for runners with 8 blades as opposed to those with 24 blades.

Kentaro Hatano

Papers

Study on an Undershot Cross-Flow Water Turbine with Straight Blades

Erratum: The Flow Field of Undershot Cross-Flow Water Turbines Based on PIV Measurements and Numerical Analysis

Study on performance and flow field of an undershot cross-flow water turbine comprising different number of blades

Improvement of Performance of Undershot Cross-Flow Water Turbines Based on Shock Loss Reduction