Hi all,
hoping folks can provide me with some thoughts on how to proceed (or not & why) with my current upgrades as there are several options.
Current Setup:
* x4 PV strings of 5 300W panels each (total of 20) wired in parallel (edited).
* x1 SmartSolar MPPT 250 | 100 - TR.
* x2 B-Box PRO 13.8 48v with a total of 27.7kWh of capacity.
* x1 Multiplus 48|5000|70.
Problem: MOAR power needed! In particular during the winter months we need more power to run our setup and we want to be able to slow-charge our EV without impacting the house system (too much).
Goal: Be able to charge our EV at ~3kWh without impacting the battery and ideally have the ability, through a transfer switch or AC-In, to funnel additonal power to the house system.
Solution: Install more PV. Operate the additional PV in a separate system which does not run through the current MPPT & Multiplus using a dedicated inverter. This way we can charge our EV without impacting the house system. To not lose any of the additionally power of system2, wire system2 into the AC-In on the Multiplus? Effectively running all loads and/or charging the batteries at times when the EV isn't charging.
Why so complicated?
1. If, I were to setup a third string and wire it to the current system the SmartSolar wouldn't be able to handle the additional voltage. Even if it were, by switching to a parallel wired array, the Multiplus would become the bottleneck. Also, I'd need an additional SmartSolar plus a Lynx to connect two SmartSolars to the single battery?
2. During max power output (parts of spring, summer and parts of autumn) the Multiplus would start to clip as it's only capable of 5kW. With the additional 3.2kW, I would end up with a total PV size of 9kW.
3. What am I forgetting?
Am I crazy?
- Are there any issues pumping power into the system via the AC-In? I've not purchased the "other" inverter and would also like any recommendation(s) folks have.
- Clipping. I will say that I've never seen a full 5kW going through the system even though it's already oversized. The max is ~4.5kW around noon/1pm. This likely has to do with the fact that the PV is flat mounted to a roof that's only about 14 degrees. As I am near Sydney, AUS +15-34 degrees would be more optimal.
