Project Name: Nepal: Central, distributed, and individual solar-LED lighting systems
Location: Humla, Nepal (map)
Organizations involved: Light Up the World, Rural Integrated Development Services (RIDS)-Nepal, University of Jyvaskyla, PPN
Number and Types of Lighting Systems: 366 households each receiving 2 luminaires with 9 Nichia NSPW510BS and 1 white LED Luxeon Star luminary were given to each house (1098 systems serving 2196 people)
Project Description: In Nepal only 40% of the population has access to electricity, and even then, they must use kerosene and oil as backup fuels for lighting, due to frequent blackouts. The other 60% of the 28.5 million population live so rurally, isolated by the Himalayas, that access to the electric grid is infeasible within the foreseeable future. The primary energy source for these people and Nepal, is firewood supplemented by crop residue and animal manure, as there are no significant fossil fuel resources in the country.
In remote Nepal, the price of these liquid fuels, kerosene and oil, increase with a village's distance from a road, as all equipment and materials must be carried from there on. This makes things difficult for communities such as Humla, a region in the northwest of Nepal, and a 16 day walk from the nearest road. Humla therefore turns to resin soaked pine ttree sticks, called “jharro” for light, contributing to the devastating deforestation in these regions and the villagers' chronic health issues. Jharro burns with half the luminous efficacy (0.04 lumen/watt) of kerosene, and 1/300th that of white LED systems.
The primary function of a home lighting system is to provide a safe visual aid while still being affordable. Smoke from jharro for lighting, and open indoor fire pits for cooking and heating, contributes to low life expectancy, averaged at 54 years, high death rates of young children, respiratory chest diseases, asthma, blindness, and heart disease in Nepal. On top of that, one kg of jharro can cost nearly US $1.70 (US $1.0 = Rs 70.42), while the average income for Humla families is US $72, $112 for farming families who sell their annual crops.
In 2000, Light up the World (LUTW) began providing LED lighting to homes of four small Nepali villages. LUTW later joined forces with Rural Integrated Development Services- Nepal (RIDS- Nepal) to implement lighting, powered by solar and water energy, in five rural Nepali villages in the Humla area. In 2007 RIDS-Nepal used solar PV systems and pico hydro power plants with white LEDs to electrify 5 villages in upper Humla, 4 with solar PV systems, and one with a 1kW pico hydro power plant.
Three different approaches were taken when setting up the lighting systems based on the distribution of houses in each village. Where all the village houses were built together, a central PV system, with one power house containing the battery bank and charge controllers, could be built. This central system would have four mounted solar PV modules with a total of 300W. In villages with scattered houses, different clusters of homes are electrified with 75W solar PV modules, each with its own battery bank and charge controller. In cases where houses are even more scattered, each home is made into an energy generating station, with 12-16W solar PV modules.
Each house was then given three white LED luminaires in all three cases. Two are put in the larger room of the house, used for cooking, creating an illuminance level of 5 lux. The third is put in the smaller room, providing 3 lux. 3 lux was found, after interviewing the villagers, to be an inadequate amount of light for moving around, so instead of being used to light the entire room, they used them for reading and other visual tasks. This worked very well, as the cost per klmh using LEDs is far less than when using jharro. The Cost of jharro per klmh is found to be US $4.36, while the cost of LEDs per klmh is only US $0.21-0.22.
The project also included estimating the minimum illuminance levels required by villagers, and various technical and economic analyses. Measured illuminance levels in the homes before the project averaged 2 lux (barely enough to see), increasing very substantially with the new systems.
Bhusal, P. A. Zahnd, M. Elohoma, and L. Halonen. 2007. "Replacing Fuel-Based Lighting with Light Emitting Diodes in Develo... LEUKOS, Vol 2, no. 4, pp 277-291.