Systematic Overestimation of Water Use

[davidreihs]

First of all, thanks a lot for the great work on LPG!

I've been using LPG for generation of electricity consumption profiles as well as warm water consumption profiles.
During an analysis of the 50 households provided with LPG, I've found that water consumption, lies significantly above national averages.
For Germany, this average would be at 125l of water usage per day ¹. Assuming that ~50% of that is used as warm water, I would assume around 62.5l of warm water consumption per day.

When analysing the 50 households, that are included with LPG; the average water consumption per day is at 155.3l and warm water consumption at 115.2l.
At first I thought that this must be due to different distribution of household sizes in Germany.
When looking at households of particular sizes, the results for each household size lies above the national average for total water and warm water consumption.

	1 Person HH	2 Person HH	3 Person HH	4 Person HH	5+ Person HH
Total water consumption per person and day	190.5	169.0	131.6	150.6	134.9
Warm water consumption per person and day	146.9	125.1	95.9	111.9	96.4

When weighting these results with the portion of total german households of a particular size ² the total consumption is 170.2l and the warm water consumption is at 128.1l.
There seems to be some overestimation of total water usage, and significant overestimation of warm water usage.

Do you have any insight, why this might be off by such a large amount from national average?
Are there certain types of households that might not be reflected in the predefined households?
Currently I am multiplying results from LPG warm water usage by 0.5 to reach more realistic average values.

Thanks a lot!

Footnotes

1. • https://www.bdew.de/service/daten-und-grafiken/trinkwasserverwendung-im-haushalt/
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2. • https://www.umweltbundesamt.de/daten/private-haushalte-konsum/strukturdaten-privater-haushalte/bevoelkerungsentwicklung-struktur-privater#immer-mehr-ein-personenhaushalte-in-deutschland
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