Your power bill can easily become one of your biggest monthly expenses. This project, created by BeepBoopWhat on Reddit, helps tackle that problem by using a Raspberry Pi to monitor solar panels and calculate their expected monthly impact on the power bill.
The project features a 3.5" LCD display panel which reads out pertinent information about power usage in real-time. The data collected comes from Envoy brand solar panels. A cycle completes every 20 seconds, calculating the expected cost or income based on tariff information provided by the power company.
The project relies on two custom scripts. One is used to pull data from the solar panels and inject it into a sqlite3 database. The other script is used to compile the data for visual output on the LCD screen by means of a custom HTML page.
If you want to read more about this project, you can check out the code on GitHub and maybe even recreate it yourself.
The original thread provides a few more details with nuance for Envoy solar panel users and information on how to integrate them into Pi projects. Be sure to follow BeepBoopWhat for more updates and future Pi projects.