My 8yo asked me why we have solar…

It made me think for a second and other than "Daddy loves a gadget" I did a quick calculation on ROI.

We have ~7kWh usable storage. It charges cheap, the unit difference is currently ~19p. That's £485 per year in reduced bills.

We get paid for export. £500 last year.

We also use 36% of the solar power we generate. Self-use was 1.8MWh last year saving us ~£500 at daytime rate.

Overall that's £1.5k last year from a system that cost £10k. Can't complain really.