Remote electricity meters are interesting things. They essentially change the way you think about the juice flowing into your home by connecting to the potentially aged box in your basement and sensing the total energy usage in your home over time. The resulting stats are often quite enlightening and may help you make wiser energy-use decisions.
This DIY solution uses a small breakout box with an IR sensor that senses an IR light that flashes when you’ve used a kilowatt hour of electricity. You could also retrofit this to work with older boxes using a light that is interrupted as the disk inside the meter spins. The sensor can tell how often the beam is interrupted and transmit that data to a computer or other device.
the box holds some minimal electronics (14 pin AVR micro, a resistor, a capacitor, and a phototransistor), the piece of rubber shades the meter, and the bungee cord holds it all together in a most attractive way. okay, i was kidding about the last part.