I’ve found this works best with cumulative kWh feeds, one for heat pump and one from Octopus. Trick here is to use the Accumulator process step, as the numbers from Octopus are kWh per half-hour.
(or you can use my python script to fetch historic data via their API - see background post)
Then create a virtual feed that simply subtracts one from the other:
You can then plot the House + Heat Pump kWh feeds as Bars with Fill, Stack and Delta with hourly, daily, weekly or monthly interval. Stacking the feeds should match the total consumption (by definition).
