Industrial waste heat recovery technologies: An economic analysis of heat transformation technologies

Abstract

Abstract In this paper, the potential of industrial waste heat for heating and cooling applications is investigated. Therefore, heat transformation technologies are presented and their technical and economic potential are discussed. First, different industrial processes and their operating temperatures are presented as possible waste heat sources as well as low temperature processes, which can be supplied with waste heat. Then, a general economic analysis is performed for three different cases of waste heat use: an absorption chiller producing cold and heat production with a compression and an absorption heat pump. The maximum acceptable investment cost for each technology is estimated and compared with the current investment cost depending on the operating hours of the system. For this, three different consumer types, Enthusiast, Real Estate and Industry, are defined to represent different expectations in interest rate, payback period and the resulting annuity factor. Instead of judging if a technology is profitable or not, it is calculated how much the system is allowed to cost in order to be competitive for certain operating hours. Combined with present day cost of the technology, this serves as a rough judgment of the market deployment process. Finally, a sensitivity analysis of the initial assumptions for the economic analysis is performed, revealing a strong influence of the annuity factor. For the present day technology cost, absorption chillers were found to be profitable for two of the three consumer types when operated for at least 2500 h per year. Electric heat pumps are profitable for all consumer types when exceeding 4000 operating hours per year while absorption heat pumps start at 3000 h of operation per year to be profitable for all consumer types.