Industrial solar process heat yield and feasibility

Abstract

Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015.

South Africa is situated in one of the highest solar irradiance regions in the world giving industries access to a substantial amount of alternative energy for their industrial process heat requirements. Industries often receive more solar energy on their premises than they need in their processes. With fuel and electricity prices increasing it means more and more industries are looking towards alternative energy solutions. The challenge is to design a system with the appropriate technologies and integration strategies to effectively access the available energy and apply it to the existing industrial process in a financially feasible manner. In this study a solar thermal system yield and financial feasibility is applied to two case study industries which have different locations and energy demands. The objective was not to compare various technologies but rather to design a system for each application using appropriate technologies and to determine the solar yield, collector area, solar fraction, component cost breakdowns and payback period. The results showed that it is possible to replace up to 60% of the energy demands through boiler preheating. For all cases the payback period was determined to be less than 8 years. Keeping in mind a typical 20 year life expectancy of a solar system and significantly lower cost of energy for solar energy makes these systems a viable alternative for industries seeking to reduce their fuel expenses, preserve their existing boiler equipment and reduce their carbon emissions.