Storage and Utilization of the Waste Heat from National Veterinary Institute (SVA), Uppsala, Sweden

The incineration furnace at National Veterinary Institute (SVA) in Uppsala, Sweden, generates a large amount of waste heat. Some of this heat is partially recovered and is used for heating one of the main buildings during the furnace operation. However, around 2,000 MWh is wasted annually due to unavailability of any storage system. This work studies in detail four different solutions to utilize the available waste heat to provide heating to neighbouring buildings. The study initiates with the quantitative analysis of the available waste heat and the heating demands of the nearby buildings. The first solution considered in this work is to use water storage tanks to provide heating to the SVA main building when the incineration process is not operational. The second considered solution is to maximize the direct use of waste heat in the SVA buildings during the incinerator operating period. As a third alternative, the first two solutions, i.e. direct use of waste heat and use of storage tank, respectively, have been studied simultaneously in various combinations. The fourth solution explores the possibility of using borehole thermal energy storage for seasonal storage of heat during summer months. The results of this study underscore the complexity of storing and using waste heat. The results suggest that the direct use of heat (i.e. the second option) results in the largest savings-to-investment ratio and the shortest payback period. The borehole thermal energy storage and the ground-source heat pump system (i.e. the fourth option) turns out to be the most profitable solution after 25 years. However, this solution requires significant investments; hence payback period is much longer compared to other design options. For shorter analysis period, e.g. 15 years, the third option, i.e. the combination of direct waste heat and storage tank, shows the highest economic profitability. It provides highest monetary savings when discounted to net present values and has the second shortest payback period. Overall, this study contributes to the understanding of heat management between different buildings and underlines the importance of demands and availability analysis to determine the optimal solution