Beginner’s questions?
Discussion
Hi all,
Ok bear with me, not considered electric cars up until now, but a change in circumstances and the new EV3 from Kia are making me look at them.
So this is probably a very very simple question,
They have a battery whose size is given in kWh.
If I go on an EV tariff it’s about 7 pence a kWh.
Looking at Ionity site, it’s 43 pence a kWh.
Does this mean if the battery is 80 kWh it takes 80x 7 p to charge? ( I understand you will never actually be putting in a full 80, cos it will never be totally empty?)
Logic tells me that’s the case, but that means a full charge at home is about £5 and at a public charger about £34. For 300 miles driving, and that sounds to good to be true?
So is my thinking wrong?
Ok bear with me, not considered electric cars up until now, but a change in circumstances and the new EV3 from Kia are making me look at them.
So this is probably a very very simple question,
They have a battery whose size is given in kWh.
If I go on an EV tariff it’s about 7 pence a kWh.
Looking at Ionity site, it’s 43 pence a kWh.
Does this mean if the battery is 80 kWh it takes 80x 7 p to charge? ( I understand you will never actually be putting in a full 80, cos it will never be totally empty?)
Logic tells me that’s the case, but that means a full charge at home is about £5 and at a public charger about £34. For 300 miles driving, and that sounds to good to be true?
So is my thinking wrong?
Slow charging should be around 95% efficient, so an 80kWh battery will take roughly 85kWh of mains electricity to fully charge.
For working out "fuel" costs, the more interesting number is probably "miles per kWh" though. If the car averages 4 miles/kWh at 8p/kWh (which would be quite efficient for an EV), you're looking at about 2p/mile. If it averages 3 miles/kWh (which would be quite low) at the same price, that'd be 2.7p/mile.
A public charger at 50p/kWh (which I think is fairly typical) would push that up to about 12-16 p/mile for an efficient/inefficient EV respectively, which is the same ballpark as a 40-55mph petrol car.
So basically charging only on expensive public chargers will cost you roughly the same to fuel as an ICE vehicle, charging at home on an EV tariff is roughly an order of magnitude cheaper (although you do have to bear in mind the more expensive day-time electricity on those tariffs).
For working out "fuel" costs, the more interesting number is probably "miles per kWh" though. If the car averages 4 miles/kWh at 8p/kWh (which would be quite efficient for an EV), you're looking at about 2p/mile. If it averages 3 miles/kWh (which would be quite low) at the same price, that'd be 2.7p/mile.
A public charger at 50p/kWh (which I think is fairly typical) would push that up to about 12-16 p/mile for an efficient/inefficient EV respectively, which is the same ballpark as a 40-55mph petrol car.
So basically charging only on expensive public chargers will cost you roughly the same to fuel as an ICE vehicle, charging at home on an EV tariff is roughly an order of magnitude cheaper (although you do have to bear in mind the more expensive day-time electricity on those tariffs).
Edited by kambites on Friday 15th November 18:25
OVO Charge Anytime EV add-on means you could charge your car at any during the day or night - you're not restricted to a few hours overnight.
This is dependent on some factors though - excess capacity, lots of wind etc. It's a bit more flexible, and doesn't impact whatever standard tariff you've chosen from OVO.
This is dependent on some factors though - excess capacity, lots of wind etc. It's a bit more flexible, and doesn't impact whatever standard tariff you've chosen from OVO.
Stevemr said:
Yes I will have a charger, and yes definitely charge at night, but previous poster seemed to indicate eve tarif was a higher rate during day, which I took to mean a higher than normal rate, which would impact on the normal house electric costs.
No, the day rate will be pretty close to the typical rate. Possibly a little higher, but if you can load shift lots of things on to running at night you'll be quids in.I have a Nissan Leaf, on average I put 25 miles of charge on it each day as that's our average use. Total electricity cost for the whole house on Octopus Go is around £90/month. That inlcudes heating hot water via an immersion heater from 4:00am to 5:00am. It also includes dishwasher every night and tumble drying 2-3 times per week.
Stevemr said:
Yes I will have a charger, and yes definitely charge at night, but previous poster seemed to indicate eve tarif was a higher rate during day, which I took to mean a higher than normal rate, which would impact on the normal house electric costs.
It depends, some are, some aren't. I doubt it will make much difference.
OP yes it really is that cheap. Also many dual rate tariffs aren't any more during the day, I currently pay 23p in the day and 5p at night. I used to cost me £7 per day to drive a TVR to work. £5 for a diesel Kia or £3.50 in a Citigo. The EV costs me 60p per day, I don't have to queue for a pump at a garage once a week to refuel and the car is warmed up and defrosted every morning when I leave.
Stevemr said:
Yes I will have a charger, and yes definitely charge at night, but previous poster seemed to indicate eve tarif was a higher rate during day, which I took to mean a higher than normal rate, which would impact on the normal house electric costs.
Intelligent Octopus Go is (SE England) 26p/kWh peak and 7p/kWh off peakYou get a minimum of 6 hours off peak (11.30pm - 5.30am) each day, and if you need more charge you can often get more hours at cheap rate. However you need either a compatible car or compatible home charger.
I think 'normal' Octopus Go is now 5 hours off peak at much the same prices, and doesn't require a compatible car or charger.
Work on putting 7kW into the battery each hour, and getting about 3.5 miles/kWh. This will give you about 25 miles range for each hour charging.
Daytime rates on tariffs which have a very cheap overnight rate (such as Octopus Go) tend to be about 1p/kWh more expensive during the day than "normal" tariffs. So definitely worth having if you have an EV, and for some people even if you don't, but it's a bit disingenuous to simply state "you get cheap electricity overnight" without mentioning that you do pay a bit more during the day.
For example our flat rate is currently 24.62p/kWh on a normal tariff with Octopus. If we move to Octopus Go it'll move to 26.02p/kWh during the day but down to either 7p or 8.5p overnight, depending on which version of the tariff.
For example our flat rate is currently 24.62p/kWh on a normal tariff with Octopus. If we move to Octopus Go it'll move to 26.02p/kWh during the day but down to either 7p or 8.5p overnight, depending on which version of the tariff.
Edited by kambites on Friday 15th November 22:28
Stevemr said:
Presumably I could put Tapo plugs on dishwasher/ washing machine drier etc and run them during the night to mitigate that.
You won’t be able to do that with Tapo’s as the machines won’t know what to do when they power up. You need appliances with delayed start built in. Stevemr said:
Ah, good point , hadn’t thought about that!!
Not unusual though - both our do. The dishwasher is delayed start, so easy. With the Bosch washing machine you set the time you want it to finish, so if you’re trying to catch low rate electricity you also need to know how long the cycle will last.You might have other motives, but watch the total cost of ownership with an EV. If you’re looking at an EV3 then compare to similar petrol car. I’ve just ordered a Kona for one of our daughters who does around 20K/yr. She should save around £200/mth (£250 on petrol but will spend £50 on electric) but it probably would have been cheaper to get her a petrol Kona and give her £200/mth towards fuel.
It does seem the price gap is narrowing, looking at Kia niro on autotrader, up to 1 year old and up to 5000 miles, the difference is only £1500 between cheapest petrol and cheapest full electric.
If you owned it 5 years, your £200 a month saving in fuel is a £12000 saving, plus cheaper servicing costs.
Obviously there would be resale value at 6 years old to consider as well. But between 6 year old 100000 mile cars, I can’t see that being much!
If you owned it 5 years, your £200 a month saving in fuel is a £12000 saving, plus cheaper servicing costs.
Obviously there would be resale value at 6 years old to consider as well. But between 6 year old 100000 mile cars, I can’t see that being much!
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