Even if you have a cheap home tariff, you have to drive an awful lot of miles to be recouping the AP over three years. If you compare the difference between eggs and eggs, or rather, Tucson and Tucson, or Countryman and Countryman etc, there is £2000+ you have to claw back in fuel savings.
Car I just sold (Corolla 2.0 hybrid) was doing 44mpg with heavy-footed driving. At 6000 miles/year that’s around £1000/year in petrol. Don’t think I’d make the £2000 back if I ran solidly on electric at the cheapest possible rate. If I can be bothered later I’ll do the maths at 10p/kWh and see how many miles I’d need to be doing to make it worth it. But when I last worked it out (before the energy hikes, so it’ll be much worse now), it wasn’t worth the extra £90/month PCP.