Inverter & Battery Sizing

Hi All

I'm very new to solar and I'm currently researching products, I'm thinking of getting a system with 16 x 420W (6720W) array on an East/West facing roof in Manchester. Would a Giv-HY 5.0 Gen 2 be able to handle this size of array? The datasheet indicates it can handle 6500W, and I assume this would be OK, am I reading this correctly? If not would I need two inverters?

I'm also looking at battery storage and a bit unsure about how to size the battery, our typical usage is around 20kWh/day with the house occupied all day, I'm not sure if it makes sense to size so that I can minimise grid export or to also factor in a switch to a TOU tariff to shift my grid usage. Does anyone have any advice on this?

If you're getting hourly smart meter readings, whack it all in an excel sheet and work out what excess energy you'd like to store for the evenings/nights and mornings. There are various solar estimators based on postcode online. During winter months you may want to consider charging the battery with off-peak energy at night.

moz East/West facing roof in Manchester

Do you mean that you have one array facing east and another facing west (8 panels on each)? If so, then easily. If not, then @hoggy has explained in another thread that the HY5 (Gen 1) can manage 5kW to house/export and 2.5kW to battery from solar at the same time if there is enough PV, so the Gen 2 with your planned PV should be able to cope fine. As long as you have a battery to charge, should you get enough light on your PV, the HY5 (Gen 1 or 2) would be able to cope with all the energy from your roof. If you happen to be able to generate in excess of 5kW from PV when the battery is full or disconnected, the inverter will simply reduce throughput to limit it to 5kW, the same as if you have an export limit of 3.68kW and no load in the house; the inverter (should be configured to) will limit export to 3.68kW. The issue will be whether you get a battery large enough to take all the surplus energy to power the house after dark, or if you oversize the battery and supplement solar with cheap-rate overnight import to power the house.

thanks for the replies, the info is really useful, I found the solar estimator at https://easy-pv.co.uk pretty good and it showed a useful model of battery utilisation

I've decided to pull the trigger on a 19 x 400W array with a 9.5kWh battery and Gen2 HY5 inverter, will hopefully make use of TOU charging overnight in the winter months. My installer is in the process of applying for DNO approval now.