Tips For System Sizing

How would I correct this issue that I got when I ran the "System Sizing" macro?

Tips for System SizingThe nameplate DC/AC ratio of your system is 1.19 and is within the reasonable range of 1.10 - 1.30. Some designs use DC/AC ratios of up to 1.5.The Figure(s) above indicate that the subarray design or operating voltages fall outside the inverter MPPT limits for one or more subarray. This may be acceptable if operating voltages are within the limits but design voltages are outside the limits.Your system uses the User-defined CEC parameters module and inverter with a MPPT voltage range of 915 VDC to 1449 VDC. There are 0 modules from the same manufacturer and 0 modules in the library from different manufacturers that would result in a rated open circuit voltage within that range for the longest string in the array, which has 23 modules per string.There are no modules in the library from the same manufacturer that meet the voltage and power requirements for the longest string in the system.There are no modules in the library from a different manufacturer that meet the voltage and power requirements for this inverter.

Hello,

I can't make a suggestion without seeing the .sam file.

Based only in the information in the text copied below, it looks like the design may be fine as it is, otherwise, you may need to choose an inverter with different MPPT voltage limits, or change them manually on the System Design page.

Best regards,
Paul.

If your library doesn't have the right inverter, that tells me that such an inverter would be very rare and hard to find. What mppt voltage should I look for? This also seems to tell me that there's something in the other design factors that are creating the need for such a rare inverter. What other design factors would create such a rare scenario?

How do I get my .sam file to you?

Hi,

You can either reply with an attachment here on the forum, or email it to sam dot support at nrel dot gov.

Best regards,
Paul.

Hi,

I don't think the implication is that this system design requires a rare inverter. You just need to choose a combination of module and inverter that work well for the system you are trying to design.

Best regards,
Paul.