Electricity Cost per kW-h Reduction by Using Peak Electricity Demand Controller in Department of Electrical Engineering, Chulachomklao Royal Military Academy

Abstract

This paper presents the reduction of electricity cost per kilowatt-hour by reducing the maximum peak demand within the dept. of electrical engineering, Chulachomklao Royal Military Academy in the second semester of 2015. The practical implementation evaluation of a peak electricity demand controller is divided into two periods. These are data collection to identify the average electricity demand characteristics per day over a period of weeks in the first two months and peak clipping over 33 kilowatts by using the controller in the last two months. For the first period, the average peak demand per week at 95% confidence level was 44.76 kilowatts with a percentage of the load factor was 54.80. After using the peak demand controller in the second period, the average peak demand per week at 95% confidence level was 42.62 kilowatts with a percentage of the load factor was 53.50. Even though the controller can reduce the peak demands, but the cost per kilowatt-hour does not decrease. The main reason is that the average electricity consumption per week in the last period was lower than the first period of 911.94 and 981.06 kilowatts-hours per week, respectively which result in the percentage of load factor in the second period was not better than the first period. However, if the controller can cut the peak demand to no more than 33 kilowatts, the percentage of the load factor will be theoretically revised to 69.08 and the cost per kilowatt-hour will be approximately decreased up to 3.27 percent or 0.1662 Bath per kilowatt-hour.