Mid range or high end system? Is it worth spending more?
Location south London.
We have some quotes for panels and batteries based of an estimated use of 4500kwh. It's hard to judge as we moved a few months ago to this larger house, bought an EV, and plan to get AC installed over winter. We will also extend in a year or two. So energy use is probably going up. House is a detached Victorian with no external wall insulation so not suitable for a heat pump right now.
The quotes are quite a range but they're all quoting different specs of equipment. So is it worth just going with the cheaper stuff or paying more for a premium brand? This is the forever home so I'm open to paying more for something that will last, but is it necessary?
On panels we can get 12-16 on each face of the roof (east/west). Most quoted for just one side but I'm minded to max the roof space whilst scaffold is up. Although scaffold to both sides of the property would also cost more.
Quotes:
Boxt - 15x 475w aiko panels, 7kw sunsynk inverter, 3x sunsynk 5kw batteries. £12.5k.
Local supplier 1 - 28x 470w infinity RT type N panels, Sig energy 12kw inverter, Sig energy 8kwh battery. £20k. (This also includes an EV charger and the home gateway)
Local supplier 1 can also do a cheaper system which I think is using fox but I haven't asked for that quote yet.
Local supplier 2 - 14x480w aiko panels, 11kw Tesla inverter, 13kwh Tesla pw3 battery. £15.5k. includes Tesla gateway.
Local supplier 2 cheaper option - 14x480w aiko panels, fox ess h1 6kw inverter, fox ess ep12 plus 11 kWh battery. 11k. No gateway.
Local supplier 3 - 12x 480w aiko panels, Sig energy 8kw inverter and 10kwh battery (this includes the home gateway option) £18k but also including 1.5k for an EV charger. So about £16.5k without it. But this doesn't include any scaffold which would be about 1-1.5k extra.
I want to be able to account for future expansion which puts me off the Tesla a bit, and I read their app isn't that great for smart programming. But really I just want to get as much power as possible for running the house and have the option to upgrade the battery in future.
We are already on an EV tariff with 8p overnight so could charge batteries on this too.
No idea about export, one local supplier told me 6kwh set up could be approved within a week but larger systems can take a bit longer and depends on location. But they said they recently installed a 30 panel 20kwh battery system close by. Tbh I am not sure I totally understand the export part yet.
Thanks for any advice!