Stand alone PV plus energy storage

I'm trying to model a megawatt scale stand alone PV array with DC coupled energy storage. No matter what discharge option I try to utilize, the ESS will not discharge and only remains at 100% SOC.

System sizes are as follows:
PV: 4.66 MWdc, 3.63 MWac
ESS: 2 MWdc, 4 MWhr capacity

It’s a standalone system so there is no load. The desire is to produce at nameplate (3.63 MWac) for as much time as possible with kWh’s being stored in the battery that would ordinarily be clipped, then allow the battery to discharge as daylight fades to maintain 3.63 MWac of output.

Hello,

For that system, you should choose the Detailed Photovoltaic performance model and Single Owner financial model. Use the System Design page to design the system to meet your DC and AC nameplate power requirements. Then on the Battery Storage page, enable the battery, and size the battery for 4000 kWh of capacity at 2000 kW.

Then, still on the Battery Storage page, for the manual dispatch model, allow PV to charge the battery for Period 1 to cover most of the year (for both weekdays and weekends), and assign Period 2 to the evening hours and allow discharge for that period.

That should result in a system that charges the battery during the day, and only discharges it during the evening hours.

However, in the current version of SAM, power "clipped" by the inverter is not delivered to the battery.

Best regards,
Paul.