Make: Technology on Your Time Volume 18

TWEET-A-WATT POWER MONITOR

By Limor Fried and Phillip Torrone

Photography by Limor Fried

WATT WATCHER

We live in a rented apartment, so we don’t have hacking access to a power meter or breaker panel. But we still wanted to measure our household power usage long-term, so we developed the Tweet-a-Watt. It uses plug-in electricity monitors at each outlet to wirelessly send readings to a base station, which assembles them into reports you can analyze and graph. It can also broadcast updates via Twitter.

Building your own power monitor isn’t too tough and can save money, but we’re not fans of sticking our fingers into 120V wiring. Instead, we built ...