West facing array

[Eric12]

Sounds promising, thats nearing my expected usage for 12 months !

[Mr Gus]

Squeezing in extra into the initial job wherever possible is something many with space wish they'd done, your usage today may not be that tomorrow, fans in more humid summers, extra heaters as folk get older, a cpap machine running through the night for example. (Closer to 100 watt hours with a built in humidifier than not)
Change over to a small ASHP, or whatever, & trying to get close to pre-existing panel specs, frame colour, & other variables down the line is a time consuming embuggerance, that'll make you wince on things like small order solar panel shipping costs due to their bulk, fragile nature (around couriers) typically requiring a more specialist delivery

Food for thought that's all I'll leave it for others to fill in, suffice to say, I find this an easy tool for calendar / seasonal rooftop expectations
suncalc.org ..might make it easier for your mum to comprehend & understand potential disruption for the duration of work & how the set up will work seasonally, many learn to do the wash et al when the sun is shining & electrons pumping rather than it go to the grid.

[Eric12]

Thanks for the link that will help for sure.