We invested in 11 panels 4.12kw system plus an 8.2kw battery the back end of last year. Best decision we ever made. Its essentially insulated us against this energy worry for now as were an electric-only household. We have a dorma window on the roof so got 5 panels on the house rood fitted round that so it can be done- we also have a detached garage so we have 6 panels on that.
It is excellent and over the summer have been basically just paying very little- around £30-£40 a month actual usage whilst building up a large energy account credit for the winter months - preparing for our electric heat pump to kick in for heating and that consumes a lot- the above summer usage includes charging a Plug in hybrid car.
the company that installed did a survey and gave us all the array and battery options with their relevant costings, estimated generation and payback time. The above system cost us about £8300. It was estimated to pay for itself in around 8 years but that was accounting for normal annual estimate increase in energy costs if 5%. It has obviously increased much more substantially than that. More than they could ever have known that so I guestimate it will actually pay for itself in 5-6 years?
any excess electricity made once the battery is full is on a SEG tariff , its pretty negligible tbh, get 4.1p/kwh, a tenner a month in summer. its tiny compared to the FIT tariff my MIL gets 16p/kwh but that’s whats on offer these days. Criminal really that I’m selling it to the grid at that yet they’re charging so much for “green energy tariffs”
with regards to the battery, we also have an octopus account that has a normal (high-ish) daytime kwh rate but overnight its 7.5kwh, so you can charge the battery up off cheap elec if anticipating a grey day. Also charge the car off that sometimes. Its an elecreic vehicle tariff so you should have an electric car really but I cant(octopus go) see how they’d know the difference between charging a car and charging a battery, its not like they can check is it?
its definitely worth asking a few companies locally to do you a survey, nothing to lose have you? If you are in yorkshire i can definitely recommend ours but I can bet they are very busy at the moment!