On the contribution of renewable energies for feeding a high altitude Smart Mini Grid

Highlights: • Off-grid renewable power generation in a smart mini-grid perspective. • Direct measurements and CFD simulation for energy resources and consumption. • Detailed distribution of wind resource in the Khumbu Valley, Everest region, Nepal. • PV/wind system with storage device, for emergency and permanent scenarios. • Important wind contribution to the energy balance and positive environmental assessment. - Abstract: Governments around the world strive to achieve ambitious targets of incorporating considerable amounts of distributed renewable generation and combined heat and power, in response to the climate-change challenge and the need to enhance fuel diversity. The scientific interest is moving toward off-grid power generation systems, based on conventional and/or renewable sources, often coupled with storage devices, which distribute power through a local grid network. This approach, applied to increase electricity access especially in remote areas, is effective to reduce poverty, mitigate climate change and improve the resilience. In this framework, the paper presents the assessment of different renewable sources for power generation in Nepal, aimed to (i) optimize the energy fluxes, (ii) evaluate the long term energy balance by comparing productions and consumption, (iii) preliminary size a multiple input/output storage device on the basis of specific boundary conditions. The study is geographically set within the Khumbu Valley, in the central part of the Himalayan Range, East Region of Nepal, recently damaged by severe seismic events causing serious consequences on population and territory. The specific features of the reference context have been assessed from different points of view, focusing on climate data, energy consumption, and available resources. Wind potential in several spots around Namche Bazar region was estimated using CFD methods, and a customized micro wind turbine – projected by University of Perugia – has been simulated to estimate a hourly production profile. With an accurate analysis of wind data and air density effects, it is possible to test energy production potential in areas with high average wind speed. The overall productions from wind turbines and solar PV panels were coupled with household load profiles; a storage system has been preliminary sized accounting technical and logistic aspects, e.g. charge limits of lead acid batteries and portability of the components in extreme conditions. Finally the avoided emissions were quantified in order to evaluate the mitigation effects on climate change.