There is increasing demand for energy in South Africa. With all the developments in townships, more people are getting water, sanitation and electricity services. This is good for the country because the quality of life is being improved daily even in the poorest of communities. However, the high demand needs to be met with high production capacity. This strains the South African power utility, Eskom. This high and increasing demand has led to very high electricity bills, power shortages, more frequent load shading, and power cuts. This negatively affects businesses. Bakeries are some of the most affected businesses. The whole production line depends on electricity. Baking requires air temperatures of 200oC - 250oC. Such temperatures can be achieved using renewable energy sources such as solar, which is abundant in South Africa. Solar irradiance in Johannesburg can be as high as 1 kW per square meter. The aim of this work was, therefore, to research, develop and design a solar powered oven for baking bread. Baking bread requires air at 2000C and oven inlet speed of 1.8m/s. Using these basic requirements, the collector size was determined and the fan parameters. The performance of the oven is evaluated by numerical modelling and shows good performance for the required airflow rates. The evacuated tube solar collectors were integrated with a domestic oven of dimensions 400×26×280mm. The system was found to require 2.182kWand with the average Johannesburg solar intensity(0.76), the required number of evacuated tubes was found to be 28. A fan is also placed at the system inlet to give good baking airflow rates, air circulation and to balance for frictional losses in the system.
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