APPLICATION OF UTILIZABILITY COMPUTATION METHODS TO EUROPE AND AFRICA

ABSTRACT Some methods for computing solar energy utilizability are applied to European and African locations and compared with actual values obtained from long-term measurements on horizontal and south-oriented tilted planes. Most of analyzed methods give acceptable results (within 20%) when the actual monthly average daily irradiation on the considered surface is known. When this value is not known (i.e. computed from monthly mean on a horiz. plane), errors on the monthly available energy above a threshold irradiance may be in the range 30—40%.