Nepal is a country full of mountains and hills. Access to the electricity grid has always been a difficult task due to difficult terrains and cost involved. Thanks to its abundant water resources, support from development partners and government policy, micro hydropower technology was introduced nearly fifty years ago in Nepal. Today more than 30,000 hydro stations with an installed capacity less than 999 kW have been installed in the country generating more than 30 MW of electricity, which provides electricity access to more than 300,000 households. Most of them were implemented under a unique model of rural electrification where the rural communities were put in charge of constructing, owning and managing hydropower plants with the government of Nepal and many I/NGOs providing subsidy and technical support.
Nepal is considered as one of the best examples in the field of micro hydropower development. This sector is able to draw global attention. Today, Nepal can share its best practices, and lessons learnt on how capacity can be built in rural communities without access to electricity to own, build and run their own mini-grid systems. Through this, Nepal has developed an excellent working experience in micro hydropower plants which contributes to the national economy and community livelihoods. However, development of the technology has not moved forward since its introduction.
A brief on MHP manufacturing in Nepal
Today, more than 80% of installed turbines in Nepal are either Crossflow or Pelton. Both the technologies were introduced in Nepal in the early 1970's. The Crossflow turbine was first manufactured in Balaju Yantra Shala Pvt. Ltd. The Pelton turbine was introduced by Butwal Technical Institute. These two companies were the pioneering companies working in the promotion of micro hydro in Nepal where the Swiss and German aid programs were crucial in the development of the sector in Nepal. BYS and BTI were not only manufacturing the technology but also training people to develop in country capabilities. The trained human resources later started opening their own manufacturing facility in different locations in Nepal. They started product supply, installation, and maintenance services to abroad. We have been reaping benefits of the approaches that we learned in the early 70's, but there were few attempts to introduce new technology in Nepal and support Nepali manufacturers to develop new turbine designs locally. Further, decades of manufacturing of the same types of turbines has saturated the turbine market and some of the manufacturers wish to diversify their capacity but have not been able to do that on their own.
Technology transfer through a unique model
Research at the University of Bristol showed that the Turgo turbine would be a suitable design for Nepali contexts, fitting between the Pelton and Crossflow offerings and able to deal with the high silt content in Nepali rivers. Nepal Yantra Shala Energy (NYSE), a micro hydro manufacturing company in Kathmandu with an experience of more than 50 years in MHP had already observed the need for Turgo turbines in their manufacturing list. However, they were unsure how to progress the idea. They had purchased one small sized Turgo turbine set and kept it in their workshop. PEEDA has been working in the field of energy access, capacity development and research for 20 years. Turbine Testing Lab at Kathmandu University provides the facilities to test turbines across a range of power outputs. These 4 institutions joined forces to form a team to develop Nepal's capacity to manufacture the Turgo turbine locally. The year 2018/19 was spent working on the design, manufacturing and testing of the Turgo turbine at a Pico scale.
- Water enters through top of the turbine runner and exits through bottom, leading to less interference between incoming and exiting water flow.
- Allows a larger flow for same size runner or a smaller runner for same power output.
- Able to operate over wide range of heads and flows efficiently.
- The Turgo fills the gap where the head is too high for Crossflow turbine, requiring the runner to be narrow, and where the head is too low for Pelton turbine, requiring a physically large runner rotating slowly.
To introduce a new micro hydropower technology to Nepal, it was important to understand the capability of micro hydro companies and the manufacturing processes that are available. This information can be used to ensure that the design of all components for a new type of turbine is appropriate for manufacture in the context of Nepal. A thorough study was conducted of the Nepali manufacturing companies which are based in Kathmandu and Butwal, central Nepal. Our study showed that manufacturers in Nepal tend to have access to the same equipment and materials, meaning that the processes for fabricating Turgo turbines tends to be very similar. However, as casting is an external process, the interface between the micro hydro companies and casting companies is a potential risk to the quality and accuracy of the Turgo cups.
The next steps for the project are to increase the technology readiness level of the Turgo turbine in Nepal. This will enable manufacturers to be equipped with all of the necessary information to design, manufacture and install Turgo turbines. A joint effort of all the partners, including HPNET, will be facilitated to improve technology readiness. There are two parts to this future research:
- Workshop on Turgo Design and Manufacture
- Open-Source Repository of Turgo Turbine System Design and Webinar
The project team will also install a micro hydropower scale Turgo turbine at a site to demonstrate its potential for the future. With these plans in place, we hope the future for the Turgo turbine in Nepal is bright!