New system tells you what is wasting power at home

MIT scientists have developed a low cost, accurate and simple system that tells you exactly how much power is being used by every appliance, lighting fixture and device in your house.
The system involves no complex installation - no wires need to be disconnected, and the placement of the postage-stamp-sized sensors over the incoming power line does not require any particular precision. The system is designed to be self-calibrating, researchers said.
Because it samples data very quickly, the sensors can pick up enough detailed information about spikes and patterns in the voltage and current, they said.
Thanks to detailed software, the system can tell the difference between every kind of light, motor and other device in the home and show exactly which ones go on and off, at what times.

The system developed by researchers from Massachusetts Institute of Technology (MIT) in the US is designed so that all of the detailed information stays right inside the user's own home, eliminating concerns about privacy that potential users may have when considering power-monitoring systems.
Tests of the system have showed its potential to save energy and greenhouse emissions - and even to improve safety.

One installation at a military base used for training exercises showed that large tents were being heated all day during winter months, even though they were unoccupied for most of the daytime hours - a significant waste of money and fuel (which, in a combat setting, could be an important logistical concern), researchers said.

Another test installation, in a home, found an anomalous voltage pattern that showed a wiring flaw that caused some copper plumbing pipes to carry a potentially dangerous live voltage, they said.
"For a long time, the premise has been that if we could get access to better information (about energy use), we would be able to create some significant savings," said Steven Leeb, a professor at MIT.
The system lets you figure out exactly how much power is being used by every appliance, lighting fixture, and device in your home, with pinpoint accuracy and at low cost.
Researchers used an array of five sensors, each slightly offset from the others, and a calibration system that tracks the readings from each sensor and figures out which one is positioned to give the strongest signal.

They developed an interface that allows users to "zoom in" on specific time segments, unveiling enough data to tell when a refrigerator turns on or off, or goes into its defrost cycle, or how often a water heater is switching on and off during the day.
The findings were published in the IEEE Sensors Journal.