Measuring energy usage


Lately I’ve been interested in measuring whole-house power consumption. I’d like to know where my electric bill is going, how often I forget to turn the lights off, how much the CFL bulbs are actually helping, etc. Besides, I really like measuring things in real-time and displaying them in interesting ways ;)

So, I’ve been pondering various ways to do this. Our house has a mechanical power meter out front, so I considered building an optical sensor that can sense the black line on the meter’s rotating disc. Apparently others have tried this, with limited success.

The other thought was to attach a clamp-on current meter in our breaker box. I was researching this idea when I stumbled upon a finished product that is pretty much exactly what I wanted to build- and for less than the price of a Fluke clamp-on attachment.

It’s called The Energy Detective. It has a pair of clamp-on probes combined with a power-line communications module that you install in your breaker box. Then there’s a display unit, which communicates over the power mains (like X10 or HomePNA) to make voltage and current readings from the sensor in the breaker box. It even has a USB interface. Their midrange model is $145, which is certainly less than I’d spend on the parts to build a similar unit from scratch.

Naturally, I had to order one. A review shall be forthcoming.

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