Hello all. Not sure this is the right category, but here goes: I’ve had Victron kit for about 10 years now. Well happy with it. May be buying a storage/garage space and was thinking of fitting a few panels and batteries for lights, tools etc. My house has 30 panels and a Quattro 8kVa, to give an idea of where I am now. Thing is, one day we may want to turn the new building into a house, so would like to be able to scale up the system.
Any suggestions? No hurry, as this may take a year or so to come to fruition.
Pick a smaller 48V inverter. You can start as small as a Multiplus 48/500. Next get a Smartsolar 100/20 MPPT. Get two 400/500W panels that you can put in series and stay under the Voc limit of the MPPT. Get 1x a modular battery like a Pylontech US5000. Get a Cerbo GX.
When you want to upgrade later you simply change the inverter to a bigger unit, add more of the same batteries and add panels plus add another MPPT for these panels.
looking at Skipper’s reply, the only different thing I would do is get a MP2/48/3000 inverter, not a 500W one. If you later want to convert this to a small house, then a second inverter can be operated in parallel. The 3kW inverter is fairly cheap due to its popularity. This will give you the ability to operate small tools as well as lights.
Additionally, I would go for a 16s battery. The Pylontechs are 15s. They are fine, I’ve got a set of 8 running myself, but being 15s and kinda pricey, they severely limit your choice in expanding the system later on.
Are you planning to live in the new house yourself or for resale?
Especially for resale, I recommend creating a special fireproof space (brick) for the inverter and batteries, as well a double empty conduit for the cables to the grid connection and a double empty conduit to the solar panels.. equipment is for the buyer of the house, maybe the buyer is republican and wants nothing to do with green energy.
I think the main issue here is the missing anti-islanding. The small MPs feature only one mains relay, therefore when using them in an ESS or in general permanently connected to grid you would need an additional external anti-islanding relay.
The MP2s all have two mains relays and are certified to be used without an external anti-islanding relay
The 48/3000 is rated at 3kVA or 2.4kW
As for the system design in general, id go for 48V and an MP2-GX.
Then all you really need is the MP and a battery, connecting loads to the ACout. And either an AC-PV or a DC MPPT.
Keep in mind that even a small system like this uses about 1kWh per day just for the standby, so the initial PV should not be too small.
Yes, I really must investigate the modern battery market. I too have Pylontech (6 of). I believe there are now lots of cheaper options. I shall have to investigate quality though.
I think you can’t rely on paralleling ‘later on’. The documentation regarding paralleling states that the serial numbers should be close to each other, implying that they should have been manufactured in the same batch. I have two in parallel and have some regrets. One has issues and the only fix offered was a replacement with the caveat that they may not play happily together. I only did this because I’m off grid and if one fails, I can use the other.
And I’m also not sure about adding newer batteries to older batteries. I’d make sure I understood what is advisable before setting my heart on this plan.
If the pi option is something you’re comfortable with, you could follow @Ektus advise to get a 16S battery. To save further costs you could build a DIY battery. Some inspiration here: Battery DIY-Kits – the Off-Grid-Garage