The major energy and utility expenses (>90%) in the Expressway Authority of Thailand (EXAT) are electricity and fuel cost therefore EXAT would like to study, examine and develop energy saving plan for reducing energy cost and formulate low carbon society (LCS). In this study, it is classified into 4 parts consisting of the electricity consumption in head office, expressway and toll plaza and possibility of using electric car. After collecting the statistic of the electricity consumption in head office, 2 brands of inverter air conditioners and 2 ...