Inclined Window Solar Box Cooker with One External Reflector Designed for the Mediterranean Latitudes

Abstract

Off-grid solar cooking in the developed and developing regions of the world is becoming one response to climate change that causes wood-fuel shortages and an increase in cost of coal, gas, and electricity production and their transportation. This paper examines a series unloaded temperature and loaded (food) performance metrics for an inclined window solar box cooker (SBC) designed for Mediterranean latitudes (35.31˚N, 24.31˚E). Solar radiation analysis using two different computer software platforms (SunCalc and Autodesk Revit® with insight plug-in software) is used to date and time-stamp the solar box cooker solar input power. Performed sensible heat tests demonstrate that the solar cooker can reach unloaded internal temperatures of 120˚C at a solar irradiance of 192 W, and a first figure of merit of 0.08 to 0.105. Food cooking metrics is performed on: whole eggs-without water, and the following with water; White medium-grain rice, rice pudding, pastitsio #2 pasta and Brown small lentils. The analytical metrics reveals that their required cooking power is 13 to 53 W; cooking energy of 94 to 210 kJ and energy density is 0.2 to 0.6 kJ⋅g−1. Using day and time-stamped computed solar input power the food cooking power efficiency varies between 6% to 8.9% for three whole eggs-without water, and 16% to 35.5% for rice, pasta, and lentils cooked in water. For water-stressed communities in traditional desert and emerging drought regions a mass-based wastewater/product metrics is used to help drive the water efficiency of the solar cooking process.