I agree with @Blastoise186. E7 is too much of an even split (discount vs raised day rate) to make any real savings against a Fixed Price tariff. CA is the best route with OVO and I've already commented with respect to other suppliers but I'll tell you what I did which is a bit unusual and also a tad scary for some people.
I went to Agile Octopus. You can use any charge point including a 2kW/granny charger. For overnight charging I'm getting a year-to-date average of around 12p snd 20p for the rest of my domestic use. Compared with the Standard Variable Tariff I'm saving about £700 a year (but the SVT is the most expensive way you can do that) and it's on a par with other discount charging tariffs. 2kW charging is easily enough for 10,000 miles a year. Maths: Charging speed is 7 miles added per hour (often called the charging speed). Five hours per night x 365 days is 12,700 miles. You are not restricted to any charging period. Midnight to 5-6am is normally the cheapest period but you can charge anytime it's cheap. Agile is always cheaper than commercial charging (50-90p / kWh).
Pros: Any charger. I can get very cheap electricity at times. Even negative prices (yes I get paid) when there is a glut of renewables. I have an air to air heat pump which averages 20p a unit and it comes out slightly cheaper than gas heating, and I'm using 8,700kWh less gas. There is no exit fee.
Cons: The scary bit is the unit price varies every half hour (wholesale settlement price related) and it can be as low as -19p (whoop whoop + money dance) or as high as 99.99p (Boo hiss!). It's effectively buying electricity on the wholesale market rather than retail and there are no safeguards on price except for the 100p/unit cap. Peak prices (4-7pm every day) tend to be in the range 30-40p but if you can mostly avoid usage during these times (certainly not charging the car) then that can be only a minor cost.
I'm not saying you should go to Agile (you need a Smart meter for that, or indeed any EV tariff) but it's one of the options out there and one that is not often talked about which is why I've laid it out in a bit if detail here. If you are only having EV charging at you house for a short while then that could be a temporary option which would be cheaper (no guarantees) than the SVT / FP tariff.
If you are thinking EV as a longer term solution then I would, as my top recommendation, go for an OVO compatible charger (charging speed 25mph) and CA.
Peter
