Solar cooking potential in Switzerland : nodal modelling and optimisation

Abstract

Solar cooking is one possible solution to reduce the domination of fossil fuel in the domestic sector and to benefit the renewable energy. This study assesses the solar cooking potential in Switzerland. A suited nodal model, based on energy balance equations of a box-type solar cooker is implemented in Matlab. Model parameters that cannot be determined experimentally or analytically are evaluated through an optimization procedure based on a Genetic Algorithm (GA). The model is able to predict the temperature of the cooking vessel with average relative error around 5%. Based on its reliability, the model is simulated over a year for different locations in Switzerland in order to determine the solar cooking potential. It is characterized by a metric which represents the number of days a year the oven could be used to cook potatoes for two persons. It is found that the cooking times of potatoes can be well predicted by an Arrhenius law with an activation energy of 74.14 kJ/mol. A potatoes cooking criterion is based on the Arrhenius equation and determines if the pot simulated temperature profile of a particular day allows to cook potatoes. The North-East of Switzerland is the least favourable area to solar cooking with theoretically around 155 cooking days per year. Around 240 cooking days are estimated in the Valais and the Grisons cantons, which represent a significant potential for solar cooking in Switzerland.