How is lifetime generation determined?
- Is it the uploaded reported total of the daily, weekly or monthly values?
- When editing the daily values due to gaps or upload interruptions, does the lifetime use these corrected values or (1) above?
Some inverters ( maybe most? ) provide a lifetime figure for energy generated in Watts Hours ( or kWh ). It starts at 0 and goes up forever. Some inverters provide a daily figure which resets to 0 every night. Some inverters including my Fronius Symo provide both figures. A daily figure can be calculated from the lifetime figure by subtracting the previous day’s life time figure from the current lifetime figure.
If you use the PVO API https://pvoutput.org/service/r2/addstatus.jsp to upload data you will need to select the c1 flag ( cumulative ) that matches the data that you are uploading I.e. lifetime or daily.
In some threads you will see a comment along the line that “ it will sort itself out after midnight “. This is the case with lifetime vs daily figures.
I hope that this answer helps.
If that is the case and given possible longevity of some panels, how does replacing inverters affect this?
For those who are interested:
OK, after a deep dive into how lifetime generation is arrived, I have found the following:
When on live view, you can edit individual 5 minute interval uploads within the limits set for the intervals before and after the one you are editing. Additionally, if you try to edit the most recent interval, it defaults to the the previous unedited values- so that is not helpful for me as my gateway is dropping uploads intermittently. Fortunately you can edit previous days’ daily values but not the current day’s (Live view day) values as it will, again, default to the unedited values.
Once the daily values are edited, it will affect the weekly totals which will affect the monthly and thus the yearly values and I assume, the lifetime generation. I was able to edit days even from years back that had erroneous entries and I did see it affect the weekly values.
Regarding dropped uploads, fortunately, despite dropping uploads, my gateway continues to report generation/consumption numbers locally and I can use these numbers to correct daily values from dropped uploads.
That’s an excellent question.
Lifetime value is based on the sum of the daily (end of day) energy value. These are the individual records shown on the ‘Your Outputs’ page.
When 5-minute data is added or updated, the total end of day energy is re-calculated and saved. This would in turn update the lifetime value. However, depending where the lifevalue is viewed, it may be dependent on the system ‘ladder’ data which is only updated once every 24hrs.
Thank you for your input. It does confirm that edited daily values will affect lifetime generation.