Energy Chart - Help (cummulative)

I have a photovoltaik power plant with small size (400W) which is logged via zwave wall plug. So the energy meter simply increases day by day the kWh counter. Is there a “simple” way to log daily energy - maybe already in a daily bar chart…to compare days in terms of daily power generation.

Thanks a lot Norbert

hi norbert,

as far as I know bar charts are not possible with the built in charting solution.

if you are ok with a “line” chart you can do it like I described here:

:wink: stefan

Stefan, thanks for your input. sounds promising…but does your daily midnight event also do the calculation for the delta…so today highscore minus yesterday highscore = today’s energy? and write this in the DB?

I was hoping to find a more “out-of-the-box” solution that simply takes the stored DB entries and does the math to show daily energy…

Bar chart would be preferred but if the rest works fine I would of course also have no big issue with simply line-graphs…
Thanks again,

i just set the “temporary” number to 0 after i write the value to the “daily” number.

here is my chart (2 weeks timeframe):
green = the temporary value, growing all day
red = the final daily usage

the only “problem” with this approach is that the “total usage per day” is optically shifted one day to the right.

here are the two rules i use:

rule "Gas Tickzähler"
    Item gaszaehler_tick received update ON
    gasverbrauch_temp.postUpdate(gasverbrauch_temp.state as DecimalType + 1)

rule "Gastagesgesamtverbrauch"
    Time cron "0 59 23 * * ?"

Any solution on how to do this without having the value shifted?