There is no way to get long term data from HA without using Influxdb or some other database. By default HA stores its history for 10 days. That’s where the Mini Graph card gets its data from.
I have created a modified version of MGC together with Influxdb + Appdaemon to get daily power generation graph.
This is useful only if you have Influxdb and Appdaemon running.
Have a lookhere for a picture.