Development of climatic zoning and energy demand prediction for Ethiopian cities in degree days

Abstract

The energy need for comfort rises as the living standard and urbanization escalate. This study intends to regionalize the climatic zones of Ethiopia and estimate the energy needs of respective regions based on the prevalent method of degree days. For this temperature data for 952 National Center for Environmental Prediction (NCEP) stations from 1979 to 2013 were used to compute the heating degree days (HDD) and cooling degree days (CDD) with base temperature of 18.3 °C and to regionalize the country into 5 ASHRAE standard zones. Within each zone, five reference cities were identified for their population size and urbanization level, namely, Goba Robe, Robe, Addis Ababa, Dire Dawa and Gode. The result has shown that the eastern and western peripheries of the country (402,552 km2) attained high CDD (2659 DD) and low HDD. The central spine of the country attained high HDD (29,981 km2) and low CDD. Between the two there are intermediate zones (zone 3 and 4) of 706,178 km2 coverage. The yearly total energy demand for comfort in Ethiopia is estimated to be 0.068 to 0.168 kJ (kJ)/°C in a unit cube of room space. That means, if all households are furnished with AC and standard of living raised, with the population size of 143,028,465 in 2030, Ethiopia demands to produce 4,689,205.7 kJ of energy.