Evaluation of innovative integration concepts of combined solar thermal and heat pump systems for efficient thermal supply of industrial processes based on case studies and the results of the project EnPro

Solar thermal energy and heat pumps are key technologies to increase the share of renewable energy in industry. In order to spread these technologies, integration barriers should be reduced, such as high investment costs, lack of experience, missing integration schemes and planning guidelines or lack of knowledge about technological developments. Within the Austrian research project EnPro appropriate guidelines for manufacturers, users and planners are being developed. Therefore, in total 12 case studies in food, paper, metal production and processing, laundries and insulation industry have been performed, three of them selected and presented in this paper. Based on a detailed assessment of the processes, their process parameters and energy demand as well as the energy supply of the industry, integration concepts of solar thermal and heat pump systems and their combinations have been developed. Possible integration concepts include the parallel use and three different variations of serial integration of solar thermal and heat pumps. As variation I solar thermal is integrated first in the supply cascade (heating demand of a process or the supply system), followed by the heat pump. Variation II is the reversal of the order while as variation III solar thermal is used as source for the heat pump. Integration points for all possible combinations have been detected in the assessed companies. The concepts will he economically evaluated. The focus is set on generalised integration schemes for solar thermal and heat pump systems and the combination of both followed by the identification of upcoming R&D topics to push the implementation of identified solutions.