Intelligent Octopus Go - Not as Cheap as First Appears
Discussion
Just bought my first EV (Genesis GV70 - great car) and have watched just about every YouTube video on the subject and worn out my ChatGPT credits doing the research.
What Octopus don't tell you is that in order to subsidise the cheap overnight rates, they charge you a higher-than-normal standing charge and a higher kWh rate for your daytime domestic usage.
I'm on a fixed domestic rate and have a good standing charge price and kWh rate. I pay a LOT less than the EV rate for standing charge and daytime rates.
The only way the special EV rates will pay back is if I do 100% of my charging at home and overnight, with an annual mileage of about 6-7k a year. Considering that some of this will be for long drives where I won't be able to get a cheap rate anyway, the benefit disappears.
I believe that rates vary by postcode, the time you lock in your rates, etc so I won't bother with the actual calculations.
I'll just recommend everyone to do an Excel analysis (or back of fag packet) - Multiply your annual usage excluding EV and calculate your annual electric cost. Then do the same on Intelligent Go at the higher rates, plus your estimated annual mileage times the kWh-per-mile rate for your particular EV, and compare the two.
If you are a high-mileage user who can charge from home all the time, there will be a mileage tipping point where it starts to save money. But if you work from home (as I do) and only do 4-5k miles pa (excluding long road trips), then it works out more expensive.
On the upside, I can charge my car at any time of day and pay the same rate regardless.
Also, if you want to save about £200 on fitting your charge at home, buy an Octopus-compatible box (I chose Ohme ePod) direct from a stockist and get a local electrician to fit it. No 4-6 weeks' wait. Ordered the box today, delivery tomorrow, sparky coming next Wednesday. You don't lose any advantages with Octopus or EDF or any other integrated providers.
Hope that helps someone.
What Octopus don't tell you is that in order to subsidise the cheap overnight rates, they charge you a higher-than-normal standing charge and a higher kWh rate for your daytime domestic usage.
I'm on a fixed domestic rate and have a good standing charge price and kWh rate. I pay a LOT less than the EV rate for standing charge and daytime rates.
The only way the special EV rates will pay back is if I do 100% of my charging at home and overnight, with an annual mileage of about 6-7k a year. Considering that some of this will be for long drives where I won't be able to get a cheap rate anyway, the benefit disappears.
I believe that rates vary by postcode, the time you lock in your rates, etc so I won't bother with the actual calculations.
I'll just recommend everyone to do an Excel analysis (or back of fag packet) - Multiply your annual usage excluding EV and calculate your annual electric cost. Then do the same on Intelligent Go at the higher rates, plus your estimated annual mileage times the kWh-per-mile rate for your particular EV, and compare the two.
If you are a high-mileage user who can charge from home all the time, there will be a mileage tipping point where it starts to save money. But if you work from home (as I do) and only do 4-5k miles pa (excluding long road trips), then it works out more expensive.
On the upside, I can charge my car at any time of day and pay the same rate regardless.
Also, if you want to save about £200 on fitting your charge at home, buy an Octopus-compatible box (I chose Ohme ePod) direct from a stockist and get a local electrician to fit it. No 4-6 weeks' wait. Ordered the box today, delivery tomorrow, sparky coming next Wednesday. You don't lose any advantages with Octopus or EDF or any other integrated providers.
Hope that helps someone.
Octopus was not cheaper for me for my first few years of EV ownership but are now, plus having solar with a battery means that I can use those 5 hours to charge my house battery during the winter.
One thing you might be missing is unless you are using more than 35kW a day in travel then you may still be in the ICE mentality of needing to fill up. Just plug in a couple of days in a row if you're doing no/low mileage then a long trip.
One thing you might be missing is unless you are using more than 35kW a day in travel then you may still be in the ICE mentality of needing to fill up. Just plug in a couple of days in a row if you're doing no/low mileage then a long trip.
Hawthornman said:
What Octopus don't tell you is that in order to subsidise the cheap overnight rates, they charge you a higher-than-normal standing charge and a higher kWh rate for your daytime domestic usage.
Hope that helps someone.
They do tell you. It's right there upfront.Hope that helps someone.
Yes, you are right that people need to do maths on this.
But it's not difficult maths.
Methinks someone has worked it out wrong. I'm with EON and pay 9p per kWh for 6 hrs per night (the whole house) and pay 27.06p per kWh in the day. Yes, the S/C is steep (IMHO) at 60p per day, but not ridiculous compared to others. My washing machine has a timer too.
My calculation is that only 120 miles per month at 3.6 m/ kWh (3.9 summer, 3.4 winter) would be enough to make it beneficial compared to the best standard charge I could find of about 23p per kWh, 24 hrs a day.
My calculation is that only 120 miles per month at 3.6 m/ kWh (3.9 summer, 3.4 winter) would be enough to make it beneficial compared to the best standard charge I could find of about 23p per kWh, 24 hrs a day.
Well, I thought I'd share the Octopus calcs.
I'm on the 12-month fixed tariff, May 2026: Standing charge £0.5022; Unit kWh £0.2215
The EV rate for my postcode (excluding the 6-hour reduction at 8p): Standing charge £0.5905; Unit kWh £0.3202
Annual non-car consumption of 3,532 kWh brings the EV rate to £380 pa more than the fixed rate.
Assuming 7,800 mpa (3.2 miles/kWh), the 12-month tariff comes to £539.91, and £195 on the EV rate, meaning that, after adding both domestic and car together, you pay an extra £36 a year on the EV rate.
So the tipping point is about 8,000 miles a year of solely charging from home. Anything over that makes sense for the EV rate, but it would need to be significantly more to be worthwhile. Running the washing machine at night saves a few quid a year, but nothing significant.
If the sums are wrong, feel free to correct.
I'm on the 12-month fixed tariff, May 2026: Standing charge £0.5022; Unit kWh £0.2215
The EV rate for my postcode (excluding the 6-hour reduction at 8p): Standing charge £0.5905; Unit kWh £0.3202
Annual non-car consumption of 3,532 kWh brings the EV rate to £380 pa more than the fixed rate.
Assuming 7,800 mpa (3.2 miles/kWh), the 12-month tariff comes to £539.91, and £195 on the EV rate, meaning that, after adding both domestic and car together, you pay an extra £36 a year on the EV rate.
So the tipping point is about 8,000 miles a year of solely charging from home. Anything over that makes sense for the EV rate, but it would need to be significantly more to be worthwhile. Running the washing machine at night saves a few quid a year, but nothing significant.
If the sums are wrong, feel free to correct.
SDK said:
You would need to be doing very low EV mileage for it not to work.
Plus you can move dishwasher and some other things to overnight, lessening day time usage.
Get solar & battery storage and the benefits are massive
Yep. Over a 1000 cycles a year combined on the dishwasher, washer and dryer adds up for the sake of setting the delay start. Plus you can move dishwasher and some other things to overnight, lessening day time usage.
Get solar & battery storage and the benefits are massive
I've never actually run the numbers but we get change out of £180 a month for a family of 4 gas and electric and 10000 miles of charge so it feels cheap enough that I can't be bothered to dig further.
I'm more aggrieved that they've changed the rewards so I'm not guaranteed my weekly coffee.
Hawthornman said:
Well, I thought I'd share the Octopus calcs.
I'm on the 12-month fixed tariff, May 2026: Standing charge £0.5022; Unit kWh £0.2215
The EV rate for my postcode (excluding the 6-hour reduction at 8p): Standing charge £0.5905; Unit kWh £0.3202
Are you comparing rates from different times? ie, is the EV rate the one that's available now, and is the May 26 pricing still available?I'm on the 12-month fixed tariff, May 2026: Standing charge £0.5022; Unit kWh £0.2215
The EV rate for my postcode (excluding the 6-hour reduction at 8p): Standing charge £0.5905; Unit kWh £0.3202
Agree with the OP. Did the calculations for an electric runabout and was distinctly underwhelmed when I saw the much higher daytime rate. And no, I don't want to listen to my washing machine while I'm asleep, and my hot water is heated by my boiler.
Scottish Power have an interesting bolt-on where you can add electric car charging anytime at 8p per kWh, without affecting your daytime unit price. This looks far more like good value to me, unless I'm missing something.
Scottish Power have an interesting bolt-on where you can add electric car charging anytime at 8p per kWh, without affecting your daytime unit price. This looks far more like good value to me, unless I'm missing something.
Edited by norscot on Tuesday 1st September 21:35
I have used it for 3 years. Heavy users (work from home, electric Aga, 5 bed house) and 2 EVs, mostly charged from home and do about 20k miles a year in the pair.
Average unit cost over the whole last 12 months = 14.5p kWh. That's 2015 prices.
So it works for us, and works well.
Average unit cost over the whole last 12 months = 14.5p kWh. That's 2015 prices.
So it works for us, and works well.
Edited by MinchCS on Tuesday 1st September 21:40
clockworks said:
It really does depend on what your overall usage is, and what load-shifting you can do.
We are currently using over 95% off-peak electricity, so 7.5p average unit cost.
House batteries work really well with IOG.
I need to sit down and work out what the payback would look like on a house battery. We're relatively low users so imagine we wouldn't need a huge battery to shift virtually all our use to the night rate. We are currently using over 95% off-peak electricity, so 7.5p average unit cost.
House batteries work really well with IOG.
Edited by _Rodders_ on Wednesday 2nd September 11:47
Hawthornman said:
So the tipping point is about 8,000 miles a year of solely charging from home. Anything over that makes sense for the EV rate, but it would need to be significantly more to be worthwhile. Running the washing machine at night saves a few quid a year, but nothing significant.
.
As well as doing about 10k miles a year, we have made effort to load shift. Washing machine and dishwasher go on at night. Tumble dryer in afternoon when our solar panels are kicking out more. .
I'm really close to getting a battery, but I'm holding out to see what prices do as salt batteries hit the market...
We could have qualified for an EV tariff when we bought the PHEV, but we have sizeable solar and battery and with the higher export rates with Octopus Intelligent Flux it works out better for us not to bother with an EV tariff...so far, things can and probably will change.
We might be slightly better off changing to an EV tariff over the winter months but Octopus have hardly changed the Int Flux rates so whatever minor savings might be made can't see as its worth the bother.
So many people are going for large storage batteries now and charging at cheap overnight rates one wonders how long this will continue before there's too much overnight draw and the energy companies back pedal somehow.
We might be slightly better off changing to an EV tariff over the winter months but Octopus have hardly changed the Int Flux rates so whatever minor savings might be made can't see as its worth the bother.
So many people are going for large storage batteries now and charging at cheap overnight rates one wonders how long this will continue before there's too much overnight draw and the energy companies back pedal somehow.
Hawthornman said:
What Octopus don't tell you is that in order to subsidise the cheap overnight rates, they charge you a higher-than-normal standing charge and a higher kWh rate for your daytime domestic usage.
It's made abundantly clear that there is a higher standing charge and peak rate.
<30 seconds on their website
Octopus standard fixed
Octopus Go
Everyone's non EV usage will be different, as will the efficiency of their EV. Your tipping point won't be representative for many others.
Edited by SWoll on Wednesday 2nd September 08:42
Smint said:
So many people are going for large storage batteries now and charging at cheap overnight rates one wonders how long this will continue before there's too much overnight draw and the energy companies back pedal somehow.
As EVs took off the gap between peak and off-peak demand was always going to narrow but it's still pretty substantial at the moment. Domestic batteries are still a drop in the ocean, although again if popularity keeps increasing they will start to have a significant effect. Ultimately I'd imagine we'll settle on tariffs which actively track demand vs supply in real-time in order to use smart batteries and EVs for short term load management.
Definitely some quick maths needed and does vary wildly on personal usage and area specific rates. OP uses around 40% more electricity before the EV than I do for example and I do 2.5-3x the annual mileage so it soon works out. I load shifted even before we ever had an EV as it just happened to line up with our timings at home so there was no change to habits there. Currently averaging as low as 10.Xp overall in a 2k mile month and no more than 13.Xp in lower mile months so works out well for us. No batteries or solar.
Even better for us is that from August Pod Point (who my charger is with) reward for "smart charging." 2p for every kW charged (capped at £100 a year). I have only ever charged between 12 and 6am anyway but if I let them control the charge within that same 6 hour window I get money back. I can only guess that they must get some kickback from the energy suppliers for helping balance the grid and pass on the saving. I'm not complaining as it has brought down the cost per mile to a ridiculous 1.3p. My wife's 125 mile round trip commute now costs around £1.50 lol.
Even better for us is that from August Pod Point (who my charger is with) reward for "smart charging." 2p for every kW charged (capped at £100 a year). I have only ever charged between 12 and 6am anyway but if I let them control the charge within that same 6 hour window I get money back. I can only guess that they must get some kickback from the energy suppliers for helping balance the grid and pass on the saving. I'm not complaining as it has brought down the cost per mile to a ridiculous 1.3p. My wife's 125 mile round trip commute now costs around £1.50 lol.
Edited by Goatwidcoat on Wednesday 2nd September 11:26
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