Evaluating the Electric Consumption of Residential Buildings: Current Practices and Future Prospects


As the construction industry transitions towards green buildings, and the number of LEED certified facilities continues to increase, the question of how to evaluate as-built energy performance becomes more important. Most homeowners rely on a monthly bill to determine their electric consumption, which is not an effective way to understand the results of most energy-saving strategies. Real-time feedback and appliance-level information is necessary, but most solutions require extensive hardware sub-metering, with a high price due to the hardware and installation costs. We argue that, in order to achieve wide adoption, the solutions need to be simple, easy to install, inexpensive and be able to return the investment in a reasonable time. In this paper we first analyze and compare the different types of technologies that are currently available for allowing homeowners to monitor their energy expenditure. Then we discuss new approaches that balance the trade-off between information and cost, and present preliminary results from a prototype Non-Intrusive Load Monitoring (NILM) system we have installed in a building.