Technical design, costs, and greenhouse gas emissions of solar Injera baking stoves

This paper presents the technical design, market penetration, costs, and greenhouse gas emissions of three types of stoves for baking Injera, which is a traditional flat bread and staple food in Ethiopia and Eritrea. The investigated stoves are an improved biomass (Mirt), an electric, and a solar stove. As solar stove, a steam based concentrating high temperature device suitable for indoor cooking, was selected for economic evaluations. Since it is not available on the market yet, material prices and labor costs are considered. After a review of traditional and high temperature solar stoves, a thorough cost analysis is presented. Various economic parameters are quantified, like the discounted payback period for the replacement of a traditional stove by a solar stove. The analysis yields that the levelized cost of useful heat for baking (LCoEuseful) with the Mirt stove is almost 2.5 times as high, and for baking with an electric stove (with domestic electricity prices) it is about 1.1 times as high as baking with the selected solar stove. This is because of fuel costs and very different efficiencies of the stoves. The saving potential of the annual CO2 emissions for substituting all the Mirt and open fire Injera stoves in Ethiopia for solar devices yields about 32.74 million tons. The equivalent CO2 emission reduction from these replacements corresponds to about 22% of the 2010 total CO2e emissions in Ethiopia.