We are developing energy communities in italy. We choose openEMS as platform where develop site that collect and show data. Which way to monitor users that are only consumers and send their data with a small budget?
i guess, i do not really understand what you need.
But you can send all data to an influx-server and make for example a visualization with grafana.
I am also not sure about your exact requirements, but if you want to use the OpenEMS software stack of OpenEMS Edge, Backend and UI, you can refer to the system architecture in our docs:
Essentially it means, that you need some IoT Edge device (like a Raspberry Pi) at the customer which runs OpenEMS Edge and reads data from local devices like energy meter (that’s what you already suggest in another thread: Consortium partner- DSO in energy communities and balancing group - #2 by francibonito). Additionally you need a cloud server which runs OpenEMS Backend and OpenEMS UI to allow real-time and historic visualization (as shown here in the docs: Introduction :: Open Energy Management System)
All of this requires quite some efforts additionally to the free and open source OpenEMS, so I recommend you have good software developers on hand or consider contracting a partner with experience in OpenEMS (like @p.wimmer from Consolinno Energy)