There are a myriad of reasons power should be monitored in any given situation, whether it's for safety, managing energy costs, or diagnosing project problems. There are plenty of smart meters on the market that can tackle any number of applications, but more engineers and makers prefer to create their own, especially when it comes to needed accuracy, which is what David00 decided to do when he built his custom power monitor.
"The Raspberry Pi Power Monitor is a combination of custom hardware and software that will allow you to monitor your unique power situation in real-time (< 0.5-second intervals), including consumption, generation, and net production, " David explains. "The data is stored in a database and displayed in a Grafana dashboard for monitoring and reporting purposes."
The system is designed around a Raspberry Pi 3B+ and uses a Microchip MCP3008 analog to digital converter, and Kill-A-Watt energy meter to monitor up to six current transformers, along with a single AC voltage reading. David then wrote some code that takes those readings and transforms them into live data on power consumption and generation.
Key metrics include total home consumption, solar PV generation, net home consumption, net home generation, total current (voltage, power, power factor values), and individual current transformer readings. David has uploaded a complete walkthrough of his build, as well as the necessary schematics and code needed to get up and running, on his GitHub repo for those interested in recreating it. He also states that he is selling DIY kits via the same GitHub page for those who might be interested.