Solar / Battery Setup, 3 Phase Supply single phase inverters, whole house backup
Hi,
In the process of installing a 7kWp solar system at our property and need some advice.
We are looking for a whole house backup system that can supply 24 hours, we use around 20kWh per day currently which is likely to increase once we replace our gas boiler in the next 12 months.
We have a 3 Phase supply that is connected to 22kw EV chargers on a 3 phase distribution unit, a single phase consumer unit on L1 that has our house on, another single phase unit on L2 that has some out buildings on including our home office.
Struggling to work out the best solution, was tempted with the 12kw 3 phase inverter, either 1 or 2 in parallel but then thought that 3 x 5kw single phase inverters in parallel would be better (higher UPS load for our main house supply) and more cost effective, using load for the house supply and aux for the out buildings, not bothered about backing up the EV chargers.
Can we have 3 x 5kw inverters split across each phase i.e. inverter 1 on L1, inverter 2 on L2 and inverter 3 on L3 and then parallel the load into a house single phase consumer unit, with the aux paralleled into the office single phase consumer unit?
We are also looking at a 48v battery supply, if we had 3 inverters with 6 x 5kw battery's would we connect each inverter to the battery bank and join all 6 battery's?
Would the solar just connect to one inverter?
Many thanks for any help with this.
We are in the UK if that matters.
Hi Roelf,
Thanks for the reply.
Yes, you are correct. I have no need for any three phase equipment except the EV charger but paralleling the 3 inverters gives me 15kw output on the load side yes?
I had assumed that I would not use the phase setting but just connect them up together on the load and aux side.
Thanks for the advice re the batteries and solar panels, does splitting the solar panels make it better somehow, I was under the impression that matching the solar array size to the size of the inverter was the best way to go?