Enhancing energy efficiency in supermarket refrigeration systems through a robust energy performance indicator.

Supermarket chains require benchmarking and analysing refrigeration performance in order to manage their energy efficiency investments. This paper contributes in robustly assessing refrigeration system energy and carbon performance in which commonly believed drivers are used to conduct correlations. Based on this, refrigeration connected load, store opening hours and external temperature were found to construct a more representative energy performance indicator (EPI) than other metrics. By using such an indicator, it is possible to identify poor performing systems from an estate portfolio and thus select sites suitable for energy saving measures. Furthermore, energy impact from introducing natural refrigerants is examined using empirical data from a UK supermarket chain. It was found that CO 2 systems have different seasonal performance than HFC systems, nonetheless on an annual basis no system has a clear edge over another. Lastly, other initiatives such as cabinet night blinds and suction pressure optimisation achieved 10% and 7% energy reduction respectively. [ABSTRACT FROM AUTHOR]