Daily Archives: May 16, 2009

Monitoring power usage with CurrentCost

Last year i was very lucky to be given a CurrentCost power meter. Unfortunately the electrical board in the townhouse we were living in didn’t really have room to fit the clamp meter and as it had 3 phase power and we only had one clamp we couldn’t really use it properly. Yesterday I finally got around to installing it in the house we’re currently living in.

CurrentCost Meter (photo by Roo Reynolds)
CurrentCost Meter (photo by Roo Reynolds)

There is a wireless connection between the meter and the clamp which goes around the active cable coming out of the normal electricity meter.

Measuring Clamp (photo by PixelFrenzy)
Measuring Clamp (photo by PixelFrenzy)

Unlike most power meters available in Australia it is possible to connect a serial cable to display to get a live reading of the power used downloaded to a computer. Using a microbroker, rrdtool and a bit of perl as glue we know have 24/7 logging of electricity usage at about 30 second intervals from which we can create pretty graphs.

Breakfast
Breakfast power usage

Unlike our last house we have electric cooktops in the current place and you can definitely tell when I started cooking breakfast for Kelly on Sunday in the graph above. It probably cost us about 20 cents in electricity.

Our idle power usage is around 550W which is pretty high and we’ll hopefully be reducing it a bit once we start identifying exactly what is using the power. Looking at a snapshot of power usage overnight its pretty clear when the fridge/freezer thermostat kicks in though.

Fridge Power Usage
Fridge Power Usage