Two Inverters/Single System

Topics: 1. General
Oct 20, 2015 at 9:37 AM
I don't have my system installed yet, but it will be a single system with two inverters... the panels will all be in the same plane and the same location. The reason for the two inverters is simply to obtain better granularity in terms of MPPT and monitoring, but in essence it IS a single system.

Is there no way to combine the inverter outputs before uploading to PVOutput? In this scenario it doesn't really make much sense to have two systems defined there. Obviously if that's the only way then it's not the end of the world.

In terms of config, the inverters will be monitored via Bluetooth - I assume that by enabling multi-inverter support both inverters will be detected from one Bluetooth MAC, or do I need to put both in the config?

Thanks
Coordinator
Oct 20, 2015 at 11:21 AM
I don't recommend to send data of multiple inverters to 1 PVO system. If 1 PV system fails, it will be difficult to detect. Better use 1 system per inverter and aggregate all the systems in 1 parent.

It should be possible however, by modifying the vwPVOdata (SUM/GROUP BY)

To let the inverters communicate with each other, they must have the same NetID (>1) and MIS_enabled=1 in the config file
Oct 22, 2015 at 12:11 PM
Thanks for the speedy response.

In reality I'll be monitoring locally too... my thoughts were that the two inverters are only really of local significance to me ( as is the fact that each inverter has two strings ) whilst the "global" interest is the output of the whole system ( given that the panels will all be the same, same orientation etc. ) However, I'm in two minds to be honest... given that PVOutput will allow you to aggregate "child" systems into one "parent" I'm not sure that it really matters, assuming that all of the same functions etc are available for the combined system.

I suppose that I can have a play once my system is live, which will still be about 4 weeks away.... just wanted to get my head around it ahead of time.

Thanks again.
Oct 28, 2015 at 9:27 AM
I have a similar configuration. 1 string -> 2500HF + 1 string -> 3000HF, on the same plane.
And a second 3000 HF on a different roof plane.

Monitoring system #1 (2 first inverters)
[a] bluetooth -> SMA Webbox (aggregator & FTP push) -> PVOutput as 1 system [ONLINE SERVICE]
[b] bluetooth -> SMA Webbox FTP server (CSV/XML database) -> Solar Analyzer Pro software (individual & aggregate charts) [LOCAL + REMOTE ACCESS]
[c] bluetooth -> SMA Webbox Web Server -> Webbox individual & aggregate charts [LOCAL + REMOTE ACCESS]
[d] bluetooth -> SMA Webbox (upload) -> Sunny Portal [ONLINE SERVICE] (**)

Monitoring system #2 (all inverters)
[e] bluetooth -> SMAspot 2.06a (*) single-inverter CSV database -> Solar Analyzer Pro software (individual & custom aggregate charts) [LOCAL + REMOTE ACCESS]
[f] bluetooth -> SMAspot 2.06a () single-inverter -> 123Solar 1.4.5 Web Server () -> PVOuput per inverter [ONLINE SERVICE]
[g] bluetooth -> SMAspot 2.06a () single-inverter -> 123Solar 1.4.5 Web Server () inverter + aggregate charts [LOCAL + REMOTE ACCESS] (**)

(*) runs on a Pogopug, Arch Linux, 16GB USB stick.
(**) charts can display all inverter data & measurements.

The most flexible aggregator is Solar Analyzer Pro. It's an interesting tool for production data analysis too.
But the tool I ended using on a daily basis is [g] (with a paced down 123Solar data acquisition rate).

( Missing : a recent SBFspot version. Would add inverter temperature & inverter synchronization )
( Missing : backfill support to Monitoring system #2 )
( Missing : queue inverter event messages to 123Solar )
Oct 28, 2015 at 10:27 AM
Thanks aldesr, very interesting. It's also interesting that you say you use [g] on a regular basis since that's one of the free solutions! I was going to have a play with Domoticz since I already use it for my heating and other control - it won't show most of the data but will give the important figures. Then was going to see about something more detailed. Must admit though I'll give the 400 quid for a webbox a miss!

Presumably when you say "single inverter" for the second system, you're producing separate databases for each one and then using the mentioned software to aggregate?