This paper proposes an optimization-based Residential Energy Management System (REMS) to minimize not only the customer's energy cost but also customer dissatisfaction with the Power Holding Company of Nigeria (PHCN). REMS is designed in such a way that when there is a person in a particular room, electrical power is supplied to that room from its main source, and once the person leaves and the room, the power supply is cut off, shutting off all appliances and devices in that room. This is achieved by the usage of a passive infrared sensor (PIR) to detect motion and an ArduinoMicrocontrollerATMEGA-328Pto process input data from the PIR sensors to determine if electrical power is needed in a room or not. A Microcontroller PIC16F877A is also used to carry out all processing activities whose result would be effected through the aid of five output devices with a Liquid Crystal Display (LCD) used to display the PIR and the microprocessor status. The current state of the prototype design is described and a brief introduction to the control approach is made.