A bit of good news for some, Tesco is stopping free ev charging soon which will mean they will be easily available Our local Tesco is normally full of phevs, 5 hour charge for 20 miles! Last year when the council ones was free they was always full and now you have to pay you can always get on https://www.electrifying.com/blog/article/tesco-to-end-free-charging-at-stores-from-november-1st
I don’t understand where you get 5 hours for 20 miles from, a full charge on the average PHEV takes approximately 3 hours @3.6 kW rate for 30 miles?
As regards 28 pence a kWh it was never going to last forever, big commercial energy users are charged 21 pence a kWh so taking into consideration operating cost 28 pence seems fair and reasonable.
Unfortunately I have suffered a brain injury and occasionally I get confused and often say the wrong thing.