Solar and batteries pays off pretty quickly and can bring you to a net zero position on electrical needs fairly easily (excess sold in summer, importing in the winter). On an annual basis I now power half of another home in addition to my own. If I take the total expected output over 25 years my electricity cost is 1/4 of what it would be from the grid per KW/h. I went 6 months last year importing almost nothing from the grid.

In the UK at least batteries and an inverter are actually quicker to pay off using an economy 7 electricity tariff since power overnight is less than half the price of during the day and is typically from Wind power and imported Nuclear from France. That can pay off in less than 4 years and will last 10-15 with li-po.

If you don't have a roof to put solar on then there are some cooperative schemes where you can own part of a solar/wind installation and still save on your bill. A national one is https://rippleenergy.com/ but there may be more local schemes that you could help fund and get the payback from, residents are banding together to build solar farms all over the country.

The big energy companies have messed up this transition to green energy terribly and its considerably cheaper to make your own power than buy from them, which lets be honest it shouldn't be.