Reduce Energy Use of Buildings: Using Smartphones to Automatically Power-Up and Power-Down Computers

Plug load is 15 to 35% of the total electricity used by building in the US, much of this is wasted on unused equipment that is fully powered-on at all times. Today explicit sensors are used to detect occupancy and control building energy use. A means of controlling plug load in buildings without requiring explicit sensors is needed. We explore how a smartphone can be used to automatically control the plug load of a user workspace by turning on and off a desktop PC in the workspace. We developed an Android application to implicitly detect the user’s occupancy in an office building and to automatically turn on and off the user’s PC in their workspace. This application verifies the presence or absence of the user. The user’s workspace then will be automatically power-up and powered-down in response to the detected presence of the user. By managing the PC’s power state, we can reduce the energy consumption of the PC and the devices that are plugged into a smart strip. A smart strip is a power strip that disconnects all outlets based on the state of a control outlet. The smart strip state is controlled by the PC’s state. With this application we expect to reduce plug load with minimized or no expenses in additional equipment to detect occupancy in a building.