Over on YouTube channel RECESSIM has uploaded a three part series on reverse engineering smart utility meters. In many locations wireless mesh smart electricity meters are installed in houses allowing for completely wireless monitoring. These mesh network devices pass the wireless data from meter to meter until the data reaches a router that is typically placed on a neighborhood power pole.
In the first video Recessim explains how a smart meter mesh network works, and demonstrates signal reception in the 900 MHz band with a USRP B200 software defined radio.
In the second video he demonstrates how he can see meter ID and power outage information from Oncor meters, explains his GNU Radio flowgraph setup and goes on to explain how he reverse engineered the data packets.
Finally in the third video he performs a few teardowns of smart meters he found on eBay, and shows his reverse engineering setup with a faraday cage. More videos are likely to be on the way, so you might want to consider subscribing to his channel for updates. Recessim is also diligently recording all the information he's discovered about the meters on his Wiki.