question

@Jamie Matheson If I have read it right and you are planning on a ESS system connected to your AC distribution orIf you are connecting to the grid, regardless too your export, the DNO will want to know what generating equipment is connected to the grid and that it is compliant. If you did connect a multiplus to the grid in ESS mode, you would send a very small amount to the grid which would alert the DNO you have a generating equipment. The only way to avoid a DNO application is to go off-grid.

If I have miss-read it and you are looking at a off-grid set up next to your grid connected distribution, then do you have a schematic of your proposed set up? Ideally you want to be seeking advice from your Victron distributor on how to arrange your system as that should be part of their service. 4.1kW seems a bit small if you are looking at meeting over half your loads without a serious amount of Pylontech batteries. I would use the below link to work out your power and energy generation. Im in the south of England and my PV generation is next to nothing at the moment whilst my energy consumption is 6 times the amount it is in the summer.

https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html

It would be worth having a look on VRM World at installations near your to see how they are performing.

https://vrm.victronenergy.com/world/

Thanks for the answer. I will be using the installation in an off grid manner. I've done the link provided previously and that gives me around 3300 kWh hours for a 4kw installation. This would be the first phase of the solar for me, hopefully then purchasing a further 4kw of solar panels.

With an AC input I was hoping I would be able to make up for the solar if it didn't meet demands at all points, I didn't realise I would have to use it in ESS mode for this to happen.

My electricity needs are not tied to the seasons as of yet, owing to a wood burner and oil central heating. So I'm fairly consistent in that this will be to meet needs outwith that.

I'm now thinking a Solar RS would more suit my needs, but I want to know whether I could use an additional array tied to a 450/100 solar controller to top up the same battery. But the literature and datasheet on it is rather vague. But I do assume by the illustration I could. Thanks

Hi @Jamie Matheson

For offgrid, Victron holds the crown as the best in the world. Bar none.

Your rationale pretty good, but you could consider running your existing grid-tied loads through the Multiplus, thus saving on duplicating ac outlets. There's a limit, usually specced as Transfer Switch capacity, and if it's not enough then you may be choosing the wrong Multi. Radical step? Nope, not at all.

By choosing between which (of 2) outlets on the Multi your various loads are connected to, you have choice as to which gets supplied by grid. Hard (for me) to explain in detail, but check it out..