can anyone check my energy calculations please ?

[s7gpt]

thanks everyone, buying an EV the month my electric charges will double is probably the worst time ever however it still looks cheaper than an ICE to run overall.

I have heard a lot of you recommend the off peak plans from octopus etc, but have any of you calculated the increase in the peak rate to get this, from my estimates if I did 8k miles a year the benefit of off peak would only be around £120 a year ( we use about 5500kwh's a year at home ) - if I increase the annual mileage to around 10k miles I start to see a saving of roughly £200 per year.

the above is based on British Gas SVR at 0.28p verses octopus at 0.37p peak and 0.075 off peak after the increases in April are applied.

that said I understand the benefits of using cleaner energy...

 

[Dilly]

thanks everyone, buying an EV the month my electric charges will double is probably the worst time ever however it still looks cheaper than an ICE to run overall.

I have heard a lot of you recommend the off peak plans from octopus etc, but have any of you calculated the increase in the peak rate to get this, from my estimates if I did 8k miles a year the benefit of off peak would only be around £120 a year ( we use about 5500kwh's a year at home ) - if I increase the annual mileage to around 10k miles I start to see a saving of roughly £200 per year.

the above is based on British Gas SVR at 0.28p verses octopus at 0.37p peak and 0.075 off peak after the increases in April are applied.

that said I understand the benefits of using cleaner energy...

I think much depends on where costs end up and I can see that inflating your peak rate just to get a cheap off peak rate may not be as viable if it dramatically increases home costs.
I can only look back at my Prius from 2018 when the average cost was 11p/mile over 18000 miles
if I compare that to the Tesla worst case scenario of 1kwh/mile (it’s never ever that bad!), that‘s still only 5p/mile
at 28p/kWh my view is you won’t see worse than 14p/mile and the overall average will be much better

 

[Spuzzz]

I’ve done a little over 1500 miles in my M3LR and put in 530kwh (total which includes charging losses). Calculated around 345 wh/m.

Interesting … your numbers make ops math pretty spot on. Can you tell us what your car measured during those 1500 miles in terms of wh/mi consumption? We could infer that the difference between the 530 and the cars figure would be combined charging loss and phantom drain.

 

[init6]

My figures for 1 year of M3 from Terslamate are :

9864 miles and 3020kwH
But I need to add 11% charging loss*
So around 340 Wh/mi

The 11% is calculated using the energy used by the charger and not delivered to the car. Teslamate and Teslafi try to calculate the energy used, but these are not as accurate as measuring from the charger.

 

[init6]

I think much depends on where costs end up and I can see that inflating your peak rate just to get a cheap off peak rate may not be as viable if it dramatically increases home costs.

This is why Octopus has never worked out for me. Fine if you can shift most of your usage to the off-peak rate, but that's not always possible. Luckily I've also paid virtually zero for my car charging so far, so I'm quids in on a fixed rate.

 

[Jason71]

This is why Octopus has never worked out for me. Fine if you can shift most of your usage to the off-peak rate, but that's not always possible. Luckily I've also paid virtually zero for my car charging so far, so I'm quids in on a fixed rate.

Traditionally economoy 7 did inflate the day rates I did not feel that historically the peak rate was particularly inflated with Octopus go. I know I am going to lose this soon but I am on 13.7p peak and 4.5p off peak. There was not a lot out there with a peak rate less than 13.7p when I signed up and overall my average cost per kwh across the two is <10p per kwh. and there certainly was not a peak rate less than that at the time.

 

[GeorgeSymonds]

Maths look more or less ok to me, maybe a tad cautious. There’s been a discussion elsewhere on the unreported charging losses which can be about 25%, plus vampire drain etc which isn’t reported in the car and if you’re a big sentry mode user will be significant. My reported consumption is high 200s, say 3.5miles per kWh reported, at my 22p per kWh that’s 6.3p a mile, factor in the 25% charging loss and vampire drain and I’m easily at 8p a mile, £800 for 10k, so not a million miles away (no pun intended)

I can’t have a smart meter due to poor mobile reception so can’t get a better tariff even if they were still available.

 

[init6]

Traditionally economoy 7 did inflate the day rates I did not feel that historically the peak rate was particularly inflated with Octopus go. I know I am going to lose this soon but I am on 13.7p peak and 4.5p off peak. There was not a lot out there with a peak rate less than 13.7p when I signed up and overall my average cost per kwh across the two is <10p per kwh. and there certainly was not a peak rate less than that at the time.

IIRC my octopus offer was around 16.5p at the time, so overall there was very little difference between it and my 2-year fixed deal. I didn't expect the public chargers to still be free, but that means I've saved even more than 5p a kW

 

[DoricJim]

Interesting … your numbers make ops math pretty spot on. Can you tell us what your car measured during those 1500 miles in terms of wh/mi consumption? We could infer that the difference between the 530 and the cars figure would be combined charging loss and phantom drain.

Car reckons 275wh/m from day one. Drove for first time in a few days.

Edited to add we cabin preheat on a regular basis before getting in the car.