Potential for development of solar and wind resource in Bhutan

Agency for International Development (USAID), the U.S. Department of Energy"s National Renewable Energy Laboratory (NREL) produced maps and data of the wind and solar resources in Bhutan. The solar resource data show that Bhutan has an adequate resource for flat-plate collectors, with annual average values of global horizontal solar radiation ranging from 4.0 to 5.5 kWh/m2-day (4.0 to 5.5 peak sun hours per day). Although some of the best potential is in northern areas with low population densities, the solar resource throughout the country is suitable for photovoltaic development. Some areas close to transmission lines may provide prospects for photovoltaic power generation projects. The resource for concentrating collectors is less promising, with annual average values of direct normal solar radiation ranging from 2.5 to 5.0 kWh/m2-day. The best resource for concentrating collectors is in the high-altitude areas in the north of the country, far from electric transmission infrastructure and load centers. The wind resource data show some areas with moderate to excellent potential in several valleys throughout the country, including a few locations near power transmission lines with good-to-excellent resource potential. Areas of good wind potential indicate where wind measurement equipment could be installed to further study the resource. Because of Bhutan"s complex terrain and land cover variation, more data based on ground measurements are required to improve understanding of the wind characteristics, particularly in valleys. The information provided in this report may be of use to energy planners in Bhutan involved in developing energy policy or planning wind and solar projects, and to energy analysts around the world interested in gaining an understanding of Bhutan"s wind and solar energy potential. (Author abstract)