Use of a Computer-Based System to Measure and Manage Energy Consumption in the Home

Energy use in homes represents 21% of US total energy demand in 2004. Managing this sector is an important priority for addressing global warming, conserving resources and improving energy security. Much energy is wasted in delivering energy services not actually used by residents. Two examples include heating/cooling and lighting of unoccupied houses and rooms, and overheating or overcooling to make up for temperature variations. IT-enabled monitoring and control technologies have played an important role in eliminating similar kinds of inefficiencies in other sectors, so it is natural to think that these systems could have an important role in the home as well. The technology level of energy control in most homes is at least 20 years old, with simple programmable thermostats still in only about a quarter of US homes. Networked thermostats, power meters and switches, and zone heating are technologies that can provide information on energy use and allow it to be controlled for distribution only when needed. In addition to direct energy savings, there is also a demand to reduce indirect needs for energy infrastructure through peak shifting, or redistributing of electricity demand more evenly throughout the day. In addition to surveying these energy management issues, this article also relates the experience of a pilot project setting up monitoring/control systems in three Sacramento homes. The design specifications of these systems combine capabilities for Web-based monitoring and control and peak shifting via pre-cooling, and load shedding. The pilot has shown that such a monitoring and control system satisfying the design parameters can be implemented via mainly off-the-shelf parts. Much work remains to be done however, to develop low-cost user friendly systems attractive to typical homeowners