I have an existing off grid system that I am intending on upgrading and updating, over to a Victron based system.
The current system is 7x 250ah 120V Battery banks (AGM) 13,700W of solar
MPPT DC charged batteries to 240 VAC through an old Magnum power inverter with a generator fail-over. (single phase)
I am intending on building a new workshop that I want to cover the roof with panels (Panels are rather affordable here) and tie that into the system. but what I was thinking is something like the image I've added.
The new workshop will be too far to run a DC couple (looking at 100-300m away)
I want to maintain the Genset for fail-over, or low production days.
Lets call Workshop System A, and Residential System B (all existing infrastructure is single phase)
Using a Multiplus II I can limit the amount that they draw from the Genset, but I was wondering about a few different things;
- Where would be the best point to AC couple
- Setting one system as a master grid with the genset
- 3 Phase at workshop, and if that could work with the System B as a single phase
- Can the additional grid inverters feed back and charge the batteries through the Multiplus?
Cheers
--===EDIT===-- and more context:
I've given up on the idea of three phase.
Current System:
Magnum Power Inverter, 120V, 15kW, remote area power system.
7 banks of 10, 12V 250Ah batteries, providing a system voltage of 120V (1,750Ah total capacity).
3x AERL Coolmax SRX HV 300/30 charge controllers.
Solar panels:
2 controllers with 20 panels each (190W) in 4 parallel banks of 5 in series.
1 controller with 12 panels (300W) in 3 parallel banks of 4 in series.
6 clusters of 12 panels (80W) totaling 72 panels with an unknown configuration.
Backup generator: Perkins Engine, Olympian Generator, 26.0 kVA, 240V, 50Hz, 1-phase.
Proposed Upgrade:
Transition to a 48V system for improved efficiency and flexibility.
Install 3x Victron MultiPlus-II 48/5000/70-50 230V Inverter Chargers in parallel to provide a total of 15kW output capacity.
300W panel system: Replace existing charge controllers with 1x Victron SmartSolar MPPT 250/70-Tr VE.Can Solar Charge Controller. Wire 12 panels in 3 parallel banks of 4 in series.
190W panel system: Replace existing charge controllers with 2x Victron SmartSolar MPPT 250/70-Tr VE.Can Solar Charge Controllers. Wire 20 panels in 4 parallel banks of 5 in series for each controller.
80W panel system: Replace the existing charge controllers with the Victron SmartSolar MPPT 250/60 Solar Charge Controller. For each cluster of 12 panels, wire them in series. This results in a total voltage of approximately 12 x 22.1V = 265.2V for each cluster. Connect two clusters in parallel with each other.
Combine the 12V 250Ah batteries in banks of 4 (17 banks) to get a total storage capacity of 4,250Ah at 48V.
Victron Ekrano GX Device for internet connection, monitoring, and generator control.
Configure the backup generator in tripping parallel mode to allow multiple charging sources and optimize the charging capacity without overloading the generator or batteries.
Implement a grid-tie inverter system on outlying houses or workshop roofs to supplement the system and reduce battery cycling by relying on grid-tied solar during the day.
To address situations where there is excess power on the AC side of the system due to power being fed in by the grid-tie inverters, we add a 4th MultiPlus unit, configured as a "dump load." The dump load MultiPlus acts as a buffer to absorb this excess power and channel it to charge the batteries when they are not fully charged. The dump load MultiPlus operates automatically, monitoring the battery status and AC load to efficiently manage the power flow in the system.
Another thought was to use three Quattros and configure the 2nd AC input to be from the grid itself and only activated in the same situation as above, but I thought that could be complicated.
