Browsing by Author "Alfayo, Rogers"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Global solar radiation distribution and available solar energy potential in Tanzania
    (University of Dar es Salaam, 1999) Alfayo, Rogers
    The subjective of this study was to assess distribution of global solar radiation and the available solar energy potential in Tanzania. The main problem in achieving this objective was scarcity of measured global solar radiation data. To overcome the problem, calculated data was used. Based on meteorological data collected between 1965 and 1990 in Tanzania, an empirical model has been developed to estimate global solar radiation on horizontal surfaces. The model uses as its inputs the following parameters: number of bright sunshine hours, relative humidity, and air temperature together with an additional parameter namely, the *atmospheric condition* as an improvement over similar existing models. The developed model was validated using measured global solar radiation data. The developed model was used to estimate global solar radiation for location in Tanzania for which no measured data exist. Because of large climatological and geographical variations, the country has been divided into nine zones (A to I). The calculated values were found to lie in the range+5% of measured ones. The distribution of global solar radiation in Tanzania has been prevented in form of tables and maps. Five solar radiation maps were prepared using both measured and estimated global solar radiations data. Radiation isoclines were drawn at intervals of 1MJm-2 day -1 . Four maps show the monthly mean global solar radiation for the months of January. April, july and October. The selected months represent the four seasons in recognition of the large seasonal variation in the country. The fifth map gives the annual mean global solar radiation distribution. The developed radiation maps show that the lowest annual average global solar radiation value, which was obtained from the southern part of the country, is 13MJm-2 day-1 while the highest is 24 MJm-2 day -1, observed from the central parts of Tanzania. The general global solar radiation distributions indicate that about 90% of the country has a comparatively high level of radiation (18 to 24 MJm-2 day -1) the minimum harvestable solar energy potential is determined to be which is about 5.3kWhm-2day -1, obtained from the least radiation month of July. This was observed in more than 75% of the country. It is recommended that further work be done on the developed model to improve its accuracy.