In one of the best quips I’ve ever heard at a scientific conference, cosmologist Max Tegmark complained about a lecturer’s vagueness and pleaded for some quantitative predictions: “numbers—you know, the kind with decimals in them.” Like Tegmark, I love data. Concrete information beats hand-waving speculation any day. So it’s awfully fun to use a home energy monitor to track your household electric power use in real time. Practical, too. Knowing how much you spend is always the first step in figuring out how to save. Studies show that people who have home energy monitors find ways to cut their electric bills.
Over the summer, data-lovers suffered a blow when Google pulled the plug on itsPowermeter website, which provided a convenient way to track your home’s electricity use. But shortly after I bemoaned its demise, I learned about several other sites that are in some ways even better. They not only display your power consumption but also analyze it for patterns that could help you save money.
To collect the data, I have a unit called The Energy Detective, which consists of a pair of sensors that you clamp around the main power cables in your circuit breaker panel. Other systems, such as those by Blue Line and WattVision, attach to your utility electric meter. All take power readings and keep a running tally you can view through a web interface or mobile app. Lots of other devices are other there—energy blogger Chris Kaiser keeps a comprehensive list—but not all can upload the data to external analysis websites.
Those sites crunch the data and give you a breakdown of where the juice went. They rely on the fact that each appliance has a telltale pattern of power demand. A fridge, for example, regularly cycles on and off—you can easily see it on a graph of your total household power consumption. In principle, the analysis algorithms could go a-huntin’ for power hogs such as broken appliances and family members who crank up the a/c when you turn your back.
Jegarakshagan R. Gokul