Surely in that case every inverter would be inefficient as they are rarely fed with the full capacity of the panels, and I'd guess they would be hybrid so DC-DC to the batteries?
No one ever complained about having too much battery storage
Not sure why you think that? Assuming the 8 panels are connected to just one MPPT input, the input voltage (Vmp) will be around 300V, so well within the optimum MPPT range for most modern inverters. i.e. that configuration should be just as efficient as having 16 panels in two strings across 2 MPPT inputs.
True, we rarely get maximum power. But MPPT tracking algorithms will adjust current draw to gain maximum input voltage x current in order to gain maximum power. The typical graph for modern PV panels' max power will show voltage ramping up quickly, with the current largely dependent on luminosity. Hence the voltage presented at the inverter for the PV string for any given luminosity (Vmp) will typically be around 80% of Voc and, unless you are running less than 6 panels, will typically be within the ideal MPPT range. Obviously a good system designer will match panel's Voc & Vmp to the ideal range for the specific inverter.
I'd generally say 10kWh would be a good idea rather than 5kwh.
Just like solar, you can't have too much battery. Don't worry about export to the grid limits, inverter capacity to power the house from the battery and think about adding the EV battery into the equation by using a V2X type of system that works on the DC side direct from the solar to the EV battery in each direction.
Is that a regulatory limit of some kind, or just a small roof? Relatively small power panels being a bit over 300 W. Modern panels are more like 500 W each.
that sucks.
I've been lead to believe by a few websites and Gary Does Solar channel on YT that inverters work better the closer to full load they get. I suppose that means I've either misunderstood (probable!) or have been mislead.No one ever complained about having too much battery storage
In addition to what @MattyS asked, have you done an energy audit to determine your peak power usage. From my experience, these days, I'd avoid only having a 3.6kW inverter - you will exceed its output capability as soon as your turn on two high-power devices (e.g. kettle and toaster). So minimum of 5kW inverter would be my suggestion.
Not sure why you think that? Assuming the 8 panels are connected to just one MPPT input, the input voltage (Vmp) will be around 300V, so well within the optimum MPPT range for most modern inverters. i.e. that configuration should be just as efficient as having 16 panels in two strings across 2 MPPT inputs.
Ah, that interpretation of better gets abused at times. The closer to 90-95% load, the more efficient for the older style inverters, but not the case with the newer multistage type that add capacity as the load increases.
Marginal, IME. 8 panels on a 5kW inverter will work just fine. And there's the longevity consideration that @T1 Terry has just raised.
Is that the inverter limit or the PV limit?
Inverter
You can only register to export from a domestic property with a 3.68 inverter, if you are not exporting would assume so.
.. and a further thought to @MattyS's question... is that 8 channels on South facing roof? If so, would be worth getting quote for 8 on the North side too - obviously not in direct sunlight, but (almost) equally good when overcast. With panels at only about £55 each these days, IMHO would be better to have as many as will fit.
Well it is what it is, in our case it's a 3 storey semi detached which when I was researching potential installers most just said no to even quoting, eventually found the right installation company who came up with a solution that works perfectly, 7 on one face, 5 on the other, 5.28 Kw PV.
