Electrical appliances, such as room coolers, refrigerators and lamps take up a significant portion of our total electricity consumption. In 2017, total electricity consumption in Hong Kong was 43,886 GWh (157,977 TJ), of which about 27% (11,703 GWh) were used by household appliances and office equipment. Hence, electrical appliances consume a substantial amount of our daily electricity demand, and thus it is prudent to promote efficient electrical appliances.