Hi,
I looks like nobody has been able to tackle your issue. It might be due, in part, to the limited information provided about your specific case. Would it be possible to provide an example of the data structure (mock data if the information is sensitive) and the exact hypothesis you would like to test in this data.
Also, it looks like you are trying to estimate the error in the measurements based on aggregate ratios (electricity consumption per capita). To the best of my knowledge, I don't think that there is any valid method to retrospectively derive such information.
Hopefully, with the additional information you may provide, experts in this board (I'm not really one of them) will be able to provide an answer.
Best,
TS
Thierry R. Sornasse