Create a windows app that runs in the system tray
It's icon will be a number, displaying 'KW'
When user hovers over icon it will display 2 numbers, Current KW & Total Today KW/h
The data comes from 5 inverters which have a basic API to get the realtime data.
The app will have a [url removed, login to view] file where the number of inverters & ip of the inverters can be stored, and the refresh rate specified in seconds.
The app will then poll the API's every x seconds, add together the values from each inverter and display a unified total figure.