Have a power hungry Arduino and looking for a dead simple solution? Fear not, hardware hacker. The community has come to your aid. There are several libraries available that abstract all of the gritty AVR commands needed to make your Arduino drowsy.
Although it’s been around for a few years now, the Kill-a-Watt and other “outlet” power monitors have gotten a lot of press for their ability to highlight the power use of many household devices that are otherwise black boxes. However, measuring your power usage 1 appliance at a time is difficult and time consuming. Even if your energy provider isn’t thinking about smart metering yet, why not analyze the energy consumed by your whole house over time?