Microhydro-Based Mini grid for Sustainable Development of Rural Communities: A Case Study of Nepal

Abstract

This chapter titled “Microhydro-Based Mini Grid for Sustainable Development of Rural Communities: A Case Study of Nepal” presents the overview of Microhydro-Based Mini Grid for Sustainable Development of Rural Communities in Nepal. Development of energy sector in Nepal demands optimum tapping of hydropower of different scales; be it through large, medium, or small size hydro plants. Large power plants are often required big capital investment and involve long constructional time, whereas small and microhydro plants (SMHP) can be installed in short time period with local initiative. Since very beginning SMHP are proved to be as cost effective, indigenous, and reliable source of electrical power. However, they also have been facing hurdles in full scale development. The main issues are low load factor, low capacity to run big machines, poor end-use pattern, and unavailability of water throughout the year. Besides the expansion of national grid to the SMHP vicinity has caused to extinct, thereby wasting the productive asset. This scenario has forced to develop integrated hydro power development model in country, in which SMHP can be operated even after the reach of grid. By this, additional revenue will be generated from surplus electricity. Second, parallel operation of two or more SMHPs can realized for sharing the common loads. Formation of such MGs would have number of benefits; it would maximize the use of spilling resource, increase load factor and improve the reliability of the overall system. These MGs can be connected with national grid if it is nearby, and operated autonomously in islanded mode and interconnected mode in specified manner. From utility perspective, the MG functions as a single entity, which can provide a better platform to interconnect SMHPs to grid. Thereby it can be operated even after the reach of grid in their sites, making MG a sustainable scheme for SMHP development. There are several sites in Nepal with potential of MG. Alternative Energy Promotion Center (AEPC) has reported 14 sites across the country with capacity ranging from 100 kWs to 1 MWs. AEPC also formed a pilot MG project in Baglung District by connecting the SMHPs along the corridor of Kalung Khola river, which was completed and commissioned in 2011. Presently, It has been drawing attention to the researchers, entrepreneurs, and professionals across the globe for the real-time study of MG. Its success stories have paved the ways for the further development of other MGs in the different parts of country.

Appendix

Figs. 9, 10, 11 and 12.

Fig. 10

Interconnection layout of SMHP-based mini grid

Fig. 11

Single line diagram of Theule Khola power house [3]

Fig. 12

SLD of interconnecting MG with grid at 33 kV feeder. In this case MG operates at 11 kV level, thereby desiring 33/11 kV interface for interconnection