Supermarkets are among the most energy intensive commercial buildings and they consume high amounts of refrigerant, thus causing significant environmental concern. Supermarkets therefore make up important targets for energy efficiency measures, one of which being heat recovery from refrigeration systems, particularly suitable for the environmentally friendly refrigerant CO<inf>2</inf>. In this work, four Swedish supermarket case studies are analyzed from a techno-economic perspective. All studied supermarkets have CO<inf>2</inf> booster systems with heat recovery and their technical efficiency are evaluated, as well as already accomplished economic savings. This study estimates the studied supermarkets are currently saving 600–6,100 € annually, which corresponds to 4–12 % of the energy costs for refrigeration and heating. Higher annual economic savings of 2,400–37,100 € (14–42 %) could be achieved if the refrigeration systems were instead controlled to cover all the heating demands in the supermarkets, or savings of 5,400–35,800 € (24–58 %) if also selling a surplus to nearby consumers. The heat recovery capacity and efficiency are parametrically explored, revealing the importance of designing systems for transcritical discharge pressures and low heating system return temperatures. The study also investigates the impact of price ratios of electricity and heat, demonstrating that recovering heat for internal use is a robust strategy under wide ranges of energy prices, while exporting surplus heat is more sensitive. Ultimately, this work shows that heat recovery solutions can significantly decrease energy costs in supermarket buildings under varying market conditions for electricity and heat, but the potential is yet to be fully realized in practice.

Supermarket refrigeration systems offer the possibility to recover significant amounts of energy. These amounts may at times be higher than what the supermarket needs. In these cases, export of heat or air conditioning to neighboring buildings is a solution for increased overall energy efficiency. However, although previous studies have demonstrated the technical viability of such systems, they are rarely implemented in practice. In this work, possible barriers to and drivers of implementation of thermal energy export from supermarkets are investigated. The empirical work consists of a mixed-method data collection and in-depth analysis of six case studies of supermarkets that are in a research collaboration project between the KTH Royal Institute of Technology in Stockholm and CIT Energy Management in Gothenburg, Sweden. The main findings indicate that several barriers, especially the split economic incentives of supermarkets and property owners and a lack of information, have significant detrimental effects on the uptake of thermal energy export solutions. Cooperative agreements between supermarkets and property owners are found to have the greatest possibility to mitigate the impact of the barriers, but standardized templates are needed to reduce their associated legal, technical, and administrative uncertainties.