There are several methods of capturing the data from electricity meters - some can be quite complex including hacking the wireless signals from newer meters, or connecting to wired data ports. However some meters simply blink an LED after a kilowatt-hour of energy has been consumer, and with one of these meters at hand, Arduino enthusiast Nicolai has done just that by creating a circuit with a light sensor and Arduino to track the "blips" from the power meter. To make the data more accessible, the Arduino is then connected to a Raspberry Pi which sends the real-time consumption data to an online service such as xively.
If you're going to reproduce such a device, take care to keep away from the mains current and also note that the energy distributor's employees may wonder what you're up to. Nevertheless, to get started visit Nicolai's website. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
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