Developing Reliable and Sustainable Micro-hydropower Systems for Developing Countries

An estimated 1 billion people worldwide are living in rural areas without access to electricity. In these rural areas, economic, geographic and political factors all combine to make local generation the most effective method for improving electricity access. In developing countries with appropriate geography, hydropower is one of the most economical methods for local generation.

Nepal has the second richest hydropower resource in the world and with many people living in rural areas there is a requirement for local generation. In Nepal, there are at least 1800 micro-hydro power (MHP) plants generating 25MW of power. These turbines (with rated power less than 100kW) are manufactured and installed by small and medium size enterprises based across Nepal. The Alternative Energy Promotion Centre (AEPC) officially recognises over 75 companies as qualified or 'provisionally qualified' to build and install MHP turbines. The process of qualification does not regulate the overall quality of each project and there are no particular national standards to adhere to. Once commissioned and handed over to a community, operation and maintenance is typically carried out by a trained operator. Whilst the training is comprehensive, the quality and regularity of maintenance is highly variable.

The results of poor maintenance and system quality are under-performance, improper operation and in worst cases, system failure. Previous research has suggested that the quality of all aspects of turbine installations in Nepal is highly variable. Without standards in place, there is no means to manage the quality of installations completed by micro-hydro manufacturers. Complacency during feasibility studies leads to incorrect sizing of turbines resulting in low load factors and operation away from rated power. In addition, poor education results in consumer misuse which can exacerbate technical problems.

Field based research will use site assessment and questionnaire surveys to assess the technical and social performance of micro-hydro plants. Issues identified during the field testing will be used to make a targeted study of all stages in a project process at a micro-hydropower manufacturer. Concurrently, the understanding of the complete design life cycle will be used to find opportunities to introduce greater quality assurance and standardisation. Through modelling and parameterised CAD, a standardised prototype will be developed for environmental conditions typical in Nepal. A hydrodynamically scaled version of this will be tested to ascertain its applicability for use with a range of heads and flow rates.