Template sensor with last good value stored in attribute

[wigster]

Hi,

Try looking at a guide I wrote subsequently. It uses a slightly updated version of this template which can also subtract sensor changes:

[GUIDE] Monitoring energy by device category and running averages

Here is a short guide to how I’ve organised monitoring of (electrical) energy consumption in HA. The main objective here was being able to track usage by category of device reduce glitching in the data and allow me to add/remove devices without losing historical per category data running averages for e.g. the last 30days’ consumption instead of the utility_meter’s tracking of e.g. this month, which is not so useful on day 3 of the month. What I’ve ended up with is something that looks like th…