Global solar radiation distribution and available solar energy potential in Tanzania

Abstract

Solar energy is found to be the best source of energy for the rural poor. It is cheap and environmentally friendly. However its potential application in Tanzania is not well researched and documented. This paper describes a prospect on solar radiation distribution and available solar energy potential. Modelling of solar energy systems requires knowledge of incoming solar radiation. An empirical model based on meteorological data collected between 1965 and 1990 in Tanzania has been developed to estimate global solar radiation on horizontal surfaces. Meteorological parameters such as sunshine hours, relative humidity, air temperature and atmospheric conditions were used in the model. The values of global solar radiation predicted by the model are in close agreement with those measured for all locations and zones where the model has been tested. The deviation was found to lie between -5% and 5%. Measured and predicted mean monthly and mean annual global solar radiation values as observed from the developed radiation maps and graphs indicate that Tanzania has high solar power potential. The lowest annual average radiation value in the country is found to be 15 MJ m-2 day-1, while the maximum value is 24 MJ m-2 day-1. The lowest radiation value in the country is obtained in July (winter), which should be sufficient to satisfy the needs of rural family demands.