October 2008, modified wallclock, reverse engineering, ATtiny microcontroller.
The Kilowatt Clock is a whimsical take on the concept of an information radiator. A modified wallclock ticks once per kilowatt-second. The clock's speed is proportional to the amount of electricity used by an entire household. Elapsed time on the Kilowatt Clock measures energy use, much like an analog power meter.
This piece is based on reverse engineering the data format used by a consumer power monitoring device which transmits energy readings using a power-line modem. The clock is retrofitted with a microcontroller circuit that demodulates data from the power line.