Hi Paul,
Thank you for this detailed feedback.
I now realize that I didn't get the principle of rainflow counting quite well. After some more reading (such as that
one
), things got much clearer.
However by looking more closely at this example, I've noticed a strange behavior of the battery power profile which seems to affect energy and efficiency data. Your feedback might be really helpful on this point as well.
In this example, a system with a PV production (15-min), a load consumption (15-min) and a 100kWh battery is modeled. The dispatch controller of the battery is an "automated grid power target" fixed at 0kW (ie. the battery is used for self-consumption increase). The battery is allowed to charge from the PV only and no ancillary equipment losses were configured.
The figure below illustrates the different power flows (grid, battery, load and PV) as well as the battery state of charge. A zoom was made on a series of 4 consecutive days without PV overproduction. In can be observe here that the battery correctly stay discharge at its minimum allowed SoC (10%). However, the battery power (in orange) in non-null (~1.27kW).
If we now look at the battery annual energy charged/discharged, we can observe a huge discrepancy between the charge and discharge energy (~7000kWh). This is certainly linked to the constant discharge power observed above.
The same observation can be made on the monthly data, where the energy to load from battery is much higher than the one to battery from PV.
Finally, it seems to affect the conversion and roundtrip efficiency too. Indeed, they seem to saturate at 100% since the energy delivered by the battery is much higher than the supplied.
As asked, you I've attached the .sam file of the project. If you need any additional information, please let me know.
Thanks for the support.
Best,
Nelson