Multi RS Solar Suitability

Q&A and troubleshooting
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1

First post here so a brief intro:

Hi, I’m Paul and based in the UK. Whilst I’m not a practicing electrician I have a reasonable understanding of both AC and DC electrical systems.
I have a small “mostly” Victron system in my camper van comprising of a Multiplus Compact 12/1600, Orion XS, MPPT Solar Controller, 200W of solar and a Smart Shunt. I installed and commissioned most of that system so I’m fairly knowledgeable about how it all works.

The project I’m currently considering is at home. I’d like to use Victron, however there seems to be a myriad of different options so was hoping for a bit of guidance on what may be a suitable solution.

The house currently has a 100A 230v single phase supply that is fed into a single distribution board.
Annual consumption is about 2500 kWh which roughly equates to 8 kWh/day for 6 months of the year and 6 kWh/day for the other 6 months.
Although not frequently, total load can go over 60A for short periods.

My idea is to have 5kW of solar (2.5kW east + 2.5kW west facing), MPPT solar controller(s), 15 kWh of 48v battery storage and a 5kW(ish) inverter/charger.
I was thinking of replacing the single distribution unit and splitting circuits into critical and non-critical on 2 separate boards.
The ultimate aim is to reduce grid usage and not too bothered about saving battery capacity for potential grid outages as I have a 5kW generator that can be used in an emergency to charge batteries and or run critical loads. Also I do not want to export any power to grid.

One potential challenge is that the the solar panels, inverter & battery would be located in/on an out building which is a 30m cable run from the main distribution board.

I’m leaning towards the Multi RS Solar 48/6000 mainly because its less wiring and takes up less space than separate components but I’m not sure if the grid meter can be 30m away from the Cerbo GX over CAN and if not, will it work effectively over Ethernet?

I appreciate that Multi’s are normally wired with all loads going through the Multi on AC Out1 and/or AC Out 2, but given the house can potentially pull 60A+ I was proposing to have all loads connected between the grid meter and Multi’s AC In and then having a change over switch on the critical loads board to switch its supply between grid and the Multi’s AC Out 1. In the event of a grid failure the critical loads would then be supplied by AC Out 1.

In the day time the house loads are very low <200W so was hoping (assuming there is some solar power) the Multi would power those loads and use any surplus for battery charging.

Not sure if anyone has such a setup or has a suggestion on a more suitable solution.
Hopefully some of that makes sense.

2

The Multi RS Solar 48/6000 is not G99 certified for grid parallel use in the UK as far as i am aware so you may want to reconsider. Location for other models due to the hum and fan noise may also be a deciding factor. You can use an ethernet energy meter as I have customers who are even greater distances than 30m from their incoming supply.

3

The Victron product range does appear to be something of a minefield for the uninitiated.
Looks like a Multiplus II GX maybe a more suitable candidate and a pair of separate solar controllers albeit more wiring.
I’m not too bothered about the noise as it would be installed in a workshop.

4

Have you considered the all-in-one Easysolar-II GX which is certified and you can still add MPPT if required.

5

I’m pretty sure I’ve researched most, if not all the Victron options and I always seem to come up against a compromise regardless of which route I follow.
The Multi RS would fit the bill I think on all but the G99 compliance. Other options have limitations on the MPPT side or become prohibitively expensive and / or a messy installation.

I have the option of 12 x 450w panels free of charge from a friend which I was hoping to make use of. The issue is that these panels have a Voc of 53V so putting 6 in series takes it over 300V. The Multi RS would have been ideal in this scenario.

There are other hybrid inverters on the market that have a similar spec to the Multi RS and have G99 certification so it may be that I go down that route purely to simplify the installation.