I live in a 1999 3 bed semi, I have 15 solar panels on a SE facing roof and an 8.2kwh storage battery.
I am paying £30 per month for combined gas and electric and I am currently nearly £300 in credit (I have been in credit now fir many years, less in the winter and more in the summer)
In addition, having installed the panels in 2015 I also get a Feed In Tariff (FIT) payment every quarter. This year, so far, those FIT payments have totalled over £600

(That FIT payments system ceased many gears ago for very obvious reasons) The FIT payments are seperate to my export earnings and dont get paid in to reduce my energy bills, they are paid into my holiday fund! My battery has been in just short of 2 years now.
The last couple of days its been so dull that my solar panels have produced virtually nothing, so I have had to charge my 8,2kwh storage battery for around 15p/kwh in the early hours (I cannot get a cheaper overnight rate because I dont have a EV)
That 8.2kwh of battery power is just enough to run my house for 24 hours. So it currently costs me roughly 50p per day in electric (exc standing charge of course) Combi gas fir hot water and heating. Tge heating has yet to be turned on, we have a gas fire in the lounge and currently thats enough heat for us.
So solar panels and battery storage has been an excellent investment for me. The downside is, depending on usage etc, payback is long not short term, think in terms of 10 -12 years. (My solar panels paid for themselves after about 9 years, battery is well on the way to match that and no I dont have a spreadsheet to prove it)
I cannot for the life of me understand why current building regs dont require, where practicable, that all new builds have both solar panels and battery storage. Think how much load doing that woukd take off the National Grid, and save households.