Half hour energy data, collected daily

I’ve managed to find a way to get data from my energy retailer in half-hour increments but the data is typically over 24 hours old. This is fine for my use but I’m struggling to work out a way to get it into HA. My read of the sensor documentation suggests that the data is for the live time period only - how can I backfill this data so I can see energy utilised the previous day in half hour increments?
I’m planning on getting the data via a python script and most likely use pyscript to update the sensor. I’ll work out how to code it but some direction around how to pass it to a sensor object historically would be much appreciated.
Many thanks!

See this topic: Spook - Not your homie

ah cool - lemme see what I can do with that. thanks muchly!