Solaredge Inverter single or 3 phase?

[ashthekid]

I have 3 phase electric coming into my property and recently converted it from commercial use to residential.

I have 11x panels of 360w each so 3.960 in total.

I don't intend to put anything back into the national grid so my question is does that make a difference to the type of inverter I can have?

I have an air source heat pump installed and no gas so everything will run off electric.

 

What are people's thoughts on the best setup?

 

I'd love o find an affordable battery storage option but is that worth the expense at the moment?

 

and i intend to use a myEddi or similar diverter to push any unused generated electric into my hot water cylinder.

[Dillsue]

As I understand it a 3 phase inverter will balance the power generated over the 3 phases so any single phase equipment, maybe your ASHP?, will only have access to a third of the generated power.  If youre only likely to ever install 3.9kw of PV seems to me a single phase 16amp/G98 limited inverter would be the way forward and connect the inverter and house loads to one phase??

 

When planning your usage remember that your PV will likely be generating next to nothing in the winter when you need the ASHP the most! 

[ashthekid]

Is that where a decent storage battery is advisable to store up for winter usage? Or does it not work like that?

[JohnMo]

That would one huge battery.

[SteamyTea]

21 hours ago, ashthekid said:

Is that where a decent storage battery is advisable to store up for winter usage? Or does it not work like that?

A well managed battery system does two things.

 

Stores energy that would have been exported

Supplies usable power

 

Ideally you want to se all generation directly as the losses are the least.

If you feel you must store energy, then a battery system needs to be able to power what you need it to i.e. a full washing machine cycle.

If you only export, over a year, say 15% of your total generation, then it is not worth storing as the combined system losses will be greater.

[Dillsue]

21 hours ago, ashthekid said:

Is that where a decent storage battery is advisable to store up for winter usage? Or does it not work like that?

If you are thinking storage for the entire winter then no it doesnt work like that unless you have container loads of batteries and a much larger array than 3.9kw to charge it through the summer.

 

If you work out your approx daily usage in the winter then compare it to battery capacity youll likely see that a typical fully charged battery will only supply you for a day or 2 if youre frugal but much less with an ASHP.

 

What a battery allows you to do is capture any excess from a sunny day and then use that excess to run the house in the evening/next morning before the sun is up again the next day. If the next day is dull youll be running on grid power pretty quickly depending on usage and battery capacity.

 

To get significantly more self generation in the winter youll likely need an array significantly bigger than 3.9kw. If you google PVGIS theres a forecasting program that estimates by year/month/hour how much youll generate. Compare the forecast winter generation to your usage calcs and youll see what the shortfall is.

[ashthekid]

It sounds like single phase inverter is the way forward & I perhaps put the ASHP and main house on one phase to put the inverter into that one solely. 
 

myEddi diverter will hopefully benefit any unused generation directly into my hot water cylinder which will hopefully ease the pressure on the ASHP and this give me slightly better efficiency overall.