Octopus Go Consideration

[Shanecb]

Hi all,

Can one of you helpful people check my maths and assist me in deciding if moving to Octopus Go is worth it?

Current Tariff:
Eon Next Flex
35.31p per kwh
Standing charge: 42.68p per day

Current Usage: 230kwh per month (pre getting the car).

I work that out to be 31 x 42.68 = £13.23 per month standing charge and £81.21 in leccy.

Total = £94.44

Assuming 3 charges a month of the car (roughly 64kwh each charge?) That's another £67.80.

Grand Total = £162.24

Octopus Go:
43.4p per kwh
12p per kwh EV overnight charging rate

Standing charge: 41.13p per day

31 x standing charge = £12.75
230kwh house usage = £99.82
192kwh EV charging overnight = £23.04

Grand Total = £135.61

I appreciate that if we ran washing machines, tumble dryers and dishwasher etc overnight this would be even better, but there's no way I'll convince the Mrs to change habits there. With exception of perhaps the delay start on the dishwasher

Also, any idea what happens to the gas tariff?
For info, we use around 900kwh in winter months and around 100 in the summer.

The tariff is 10.30p per kwh and 28.48p per day.

Thank you to any budding mathematicians out there!

 

[MoDolph]

I can't see anything obviously wrong apart from a full charge is 61.7kWh as that is the useable capacity and it'll only be ~90% efficient when charging so multiply that by 1.1.

If anything that should push it even further in the favour of the octopus tariff.

 

[Shanecb]

Thank you, that's really helpful! I'd obviously top up charge a few times a week rather than doing 3 full charges as it wouldn't fully charge in time to capture the cheaper rate.

If anyone knows what the score is with the gas, I'll just double check that it's not massively more and then give them a call to sort the switch.

 

[Greenie]

Thank you, that's really helpful! I'd obviously top up charge a few times a week rather than doing 3 full charges as it wouldn't fully charge in time to capture the cheaper rate.

If anyone knows what the score is with the gas, I'll just double check that it's not massively more and then give them a call to sort the swi we're always put our

We're in the habit of putting our washing machine and dish washer on at the same time as we've always done (8am and 6pm respectively). We then set an appropriate delay on each machine to ensure they come on during the low tariff period. This has the added advantage that we can put more stuff into our appliances before they 'start'. The tumbler drier's a different matter. You just have to 'suck it up'.

 

[Jomarkh]

You don't have to move your gas to Octopus so keep it where it is if it's cheaper.

 

[smokie]

The gas is completely independent of the electricity

We're in the habit of putting our washing machine and dish washer on at the same time as we've always done (8am and 6pm respectively). We then set an appropriate delay on each machine to ensure they come on during the low tariff period. This has the added advantage that we can put more stuff into our appliances before they 'start'. The tumbler drier's a different matter. You just have to 'suck it up'.

Luckily my 4hr time slot starts at 21:30 (till this tariff runs out!) so the washing machine, dishwasher and tumble drier all usually wait till then. I even often defer boiling the kettle till after then for an evening brew!

There have been concerns raised over running tumble driers overnight but this can be mitigated by regularly cleaning out the fluff. Mine is no in the main house anyway so I'm less concerned.

 

[Cocijo]

Hi all,

Can one of you helpful people check my maths and assist me in deciding if moving to Octopus Go is worth it?

Current Tariff:
Eon Next Flex
35.31p per kwh
Standing charge: 42.68p per day

Current Usage: 230kwh per month (pre getting the car).

I work that out to be 31 x 42.68 = £13.23 per month standing charge and £81.21 in leccy.

Total = £94.44

Assuming 3 charges a month of the car (roughly 64kwh each charge?) That's another £67.80.

Grand Total = £162.24

Octopus Go:
43.4p per kwh
12p per kwh EV overnight charging rate

Standing charge: 41.13p per day

31 x standing charge = £12.75
230kwh house usage = £99.82
192kwh EV charging overnight = £23.04

Grand Total = £135.61

I appreciate that if we ran washing machines, tumble dryers and dishwasher etc overnight this would be even better, but there's no way I'll convince the Mrs to change habits there. With exception of perhaps the delay start on the dishwasher

Also, any idea what happens to the gas tariff?
For info, we use around 900kwh in winter months and around 100 in the summer.

The tariff is 10.30p per kwh and 28.48p per day.

Thank you to any budding mathematicians out there!

Your maths looks good. If you know the mileage that you travel each year you can work out your electricity used for charging (approximately) Say you travel 10k miles a year at an average of 4miles/KwHr thats approx 2500kw a year for charging. So if you charge solely off peak on octopus that’s £300. Most people average between 3 and 4 miles per KwHr but this obviously can vary. Don’t forget it’s not fixed but variable these days, but you can switch at any time if it’s not working out. Finally don’t forget to use a referral to get the extra £50 if you go for it!

 

[Shanecb]

Thanks @Cocijo, I'll work out the annual mileage for a more firmed up calculation. I must say, the call into Octopus was easy and a no brainer as long as I charge my car at least once per month (which with the current weather I certainly will be!)

 

[Cocijo]

No problem!

 

[Gomev]

If you know how much you use either daily or weekly or annually and the Octopus Go rates in your area this will work out the break even point between staying on a SV rate or switching to Octopus Go or vice versa.
The break even point is the number of kWh per week that you would need to use on the Go overnight rate in addition to the weekly home usage. So....

Included a screenshot here of the tariff in my area, Yorkshire with costs based on daily usage of between 5 and 20kWh per day. This should give a flavour for most as costs don't vary too much.

As you can see the break even point is approx. one quarter of your usage needs to be at off peak in total. Any more you are quids in, any less don't bother.

​

 

[Ian MG5]

Hi
We have been on octopus go since March
I thought my wife would never put the dishwasher and washer during the night to save money but after a couple of weeks it became a habit
So just give her a quick maths lesson on how much you will save putting them on between 12:30 and 4:30 am and she’ll soon get the hang of it

 

[smokie]

Hope you got her a new frock for Chrimbo to thank her

 

[BarryH]

Hi all,

Can one of you helpful people check my maths and assist me in deciding if moving to Octopus Go is worth it?

Current Tariff:
Eon Next Flex
35.31p per kwh
Standing charge: 42.68p per day

Current Usage: 230kwh per month (pre getting the car).

I work that out to be 31 x 42.68 = £13.23 per month standing charge and £81.21 in leccy.

Total = £94.44

Assuming 3 charges a month of the car (roughly 64kwh each charge?) That's another £67.80.

Grand Total = £162.24

Octopus Go:
43.4p per kwh
12p per kwh EV overnight charging rate

Standing charge: 41.13p per day

31 x standing charge = £12.75
230kwh house usage = £99.82
192kwh EV charging overnight = £23.04

Grand Total = £135.61

I appreciate that if we ran washing machines, tumble dryers and dishwasher etc overnight this would be even better, but there's no way I'll convince the Mrs to change habits there. With exception of perhaps the delay start on the dishwasher

Also, any idea what happens to the gas tariff?
For info, we use around 900kwh in winter months and around 100 in the summer.

The tariff is 10.30p per kwh and 28.48p per day.

Thank you to any budding mathematicians out there!

I mean since you haven't yet got the car to know how your driving style will actually affect the Miles per kWh you can't know if 3 equivalent charges a month will work out, so I'd run your calculations with 2 miles (winter), 3 miles and 4 miles (summer) to give yourself a feeling for the range of full charge equivalents per month.

The second thing is that you will need more than 64 kWh of leccy to put 64 kWh into your car as there are charging losses when charging. I'd try to avoid the charge from 80% to 100% as losses are higher at this end of the charging curve even when charging from home at 7 kW.

Finally, I have been with Octopus for years, but I just renewed when my Fixed Rate ended earlier this month and although the website says 12 p and the call agent said I'd get 12 p, the email confirming the deal said 14.89 p which is disconcerting. Has anyone else had this recently?

 

[Shanecb]

Thanks for this Barry. I do have the car already so am fairly confident that I'll only be charging a few full charges equivalent per month. I guess if the charging takes more than 64kwh due to losses or I use more, then I only stand to benefit more from the tariff. I'll watch out for the difference in pricing though...

 

[BarryH]

Thanks for this Barry. I do have the car already so am fairly confident that I'll only be charging a few full charges equivalent per month. I guess if the charging takes more than 64kwh due to losses or I use more, then I only stand to benefit more from the tariff. I'll watch out for the difference in pricing though...

You have to look at the bigger picture. I have with the use of delayed timers time-shifted heavy usage ie D-washer and Washing Machine to the Octopus Go period. I also keep a close eye on the Gas v Go effective cost per kWh for water heating. During the Winter when I run my boiler at 50C for maximum condensing performance it isn't hot enough for recharging my SunAmp Heat Battery for domestic hot water. I have found that running the Gas boiler at 60C flow temperature is over the 58C minimum to recharge the SunAmp but the Sun Amp takes 10 kWh of Gas to recharge against 5 kWh to recharge with off-peak Go electricity. So even if Go is 15p and Gas is 10p /kWh; Go is 25p a day cheaper ie over £90/year.

The net effect of my efforts is that between 52% and 55% of my electricity consumption is now at the Go off-peak. 6 weeks ago I had Solar PV put on the roof but they aren't live yet, but next week I will have 10.4 kWh of batteries and Hybrid Inverter installed and commissioned which should get charged overnight in the winter months and through the day in the summers I'm expecting 90+% Grid Power to be at Go Off-Peak.

 

[Shanecb]

Great set up