Intelligent Octopus Go limiting cheap charging.

MattMattMattUK

pensionpawn said:

QrizB said:

pensionpawn said:

QrizB said:

pensionpawn said:

I am considering acquiring my first EV next year, which would have an 84 kWhr battery. Having not investigated EV / overnight tariffs in detail, is there a tariff limit (I appreciate that there are electrical considerations) to the amount of kWhrs that can be imported over the 6 hour cheaper period?

No tariff limit, AFAIK.

However unless you're going to get clever with both the car and the charger, you'll be limited to charging at ~7kW (32A at whatever voltage you happen to have) so six hours will only give you 42kWh of charge.

11kW and 22kW chargers exist, and some cars are able to use them, but that needs three phase power.

I know that I have a 100A fuse to the house and that my electric shower can draw 10kWs without any issues, so I'm not sure why charging an EV at around 12 kWs should require an upgrade to 3 phase?

When AC charging, the wallbox just manages the supply to the vehicle. The battery charger (the bit that does AC to DC conversion) is built into the vehicle.

Most cars only have 7kW built-in chargers (32A single-phase). Some manufacturers offer larger chargers on some models, either 11kW (16A 3-phase) or 22kW (32A 3-phase).

I've not seen a light vehicle with a single-phase charger above 32A.

Edit to add: EV geeks if I've got this wrong and there is a higher-power single-phase option, please let me know!

DC fast charging. Not available yet (hopefully next year, hence my original post timeline and query about tariff kWhr caps)
https://wallbox.com/en_uk/ev-charging-101
https://futurechargingsolutions.co.uk/bidirectional-storage/#:~:text=The Wallbox Quasar 2 is a bi-directional,mm x 338 mm x 127 mm

DC fast charging is already a thing on commercial installations, but it is very expensive, the AC to DC converters are costly to install, large and just really are not needed in a domestic situation. DC fast changing exists so people can put in a lot of miles in a short amount of time when on a journey, hence 150kW+ chargers, no one needs that speed at home because they are not trying to charge in twenty minutes, neither do you want to regularly fast charge the battery, whilst it is nowhere near as damaging as initially thought it will still accelerate battery degradation (probably cost an additional 5% capacity loss over ten years). Added to which the battery will throttle down the charge speed significantly when over 80% SOC.

Overnight charging should give all but the most extreme drivers, or incredibly inefficient vehicles, so unless people are driving a huge distance every day or drive an electric bus then they really do not need more at home.
7kW = 42kWh = 150-170 miles
11kW = 66kWh = 230-265 miles

pensionpawn said:

born_again said:

pensionpawn said:

I am considering acquiring my first EV next year, which would have an 84 kWhr battery. Having not investigated EV / overnight tariffs in detail, is there a tariff limit (I appreciate that there are electrical considerations) to the amount of kWhrs that can be imported over the 6 hour cheaper period?

Well the good news is unless you are doing long runs everyday. You do not need to charge every day.
So you can just add a % as & when required.

So given IOG new limits you would get 42kW in the 6 hours (subject to some loss)

Well, hopefully 72 kWhrs as the Wallbox Quaser 2 charger is capable of 12 kWs..

Why do you think you need so much power every night?

chrisw

AsTree_pipe99 said:

born_again said:

pensionpawn said:

I am considering acquiring my first EV next year, which would have an 84 kWhr battery. Having not investigated EV / overnight tariffs in detail, is there a tariff limit (I appreciate that there are electrical considerations) to the amount of kWhrs that can be imported over the 6 hour cheaper period?

Well the good news is unless you are doing long runs everyday. You do not need to charge every day.
So you can just add a % as & when required.

So given IOG new limits you would get 42kW in the 6 hours (subject to some loss)

The 42kW assumes your charger gives you the full 7kWh for the whole 6 hours. Some will give a lower speed at times, depending on conditions.

Some chargers, particularly Ohme, have been throttling charge rates according to conditions. Octopus were seemingly unaware of this and have begun discussions with the charger manufacturers to come up with a solution before the limit is actively implemented.

_Sam_

chrisw said:

Some chargers, particularly Ohme, have been throttling charge rates according to conditions. Octopus were seemingly unaware of this and have begun discussions with the charger manufacturers to come up with a solution before the limit is actively implemented.

Zappi could be doing it too (unless it is something that can be changed in settings). At the moment our car is charging but is only getting 6.1kW, while the house is using 4kW. (Then it was first plugged in earlier this morning, the car was pulling 7.4kW which then gradually dropped to 6kW)

pensionpawn

MattMattMattUK said:

pensionpawn said:

QrizB said:

pensionpawn said:

QrizB said:

pensionpawn said:

I am considering acquiring my first EV next year, which would have an 84 kWhr battery. Having not investigated EV / overnight tariffs in detail, is there a tariff limit (I appreciate that there are electrical considerations) to the amount of kWhrs that can be imported over the 6 hour cheaper period?

No tariff limit, AFAIK.

However unless you're going to get clever with both the car and the charger, you'll be limited to charging at ~7kW (32A at whatever voltage you happen to have) so six hours will only give you 42kWh of charge.

11kW and 22kW chargers exist, and some cars are able to use them, but that needs three phase power.

I know that I have a 100A fuse to the house and that my electric shower can draw 10kWs without any issues, so I'm not sure why charging an EV at around 12 kWs should require an upgrade to 3 phase?

When AC charging, the wallbox just manages the supply to the vehicle. The battery charger (the bit that does AC to DC conversion) is built into the vehicle.

Most cars only have 7kW built-in chargers (32A single-phase). Some manufacturers offer larger chargers on some models, either 11kW (16A 3-phase) or 22kW (32A 3-phase).

I've not seen a light vehicle with a single-phase charger above 32A.

Edit to add: EV geeks if I've got this wrong and there is a higher-power single-phase option, please let me know!

DC fast charging. Not available yet (hopefully next year, hence my original post timeline and query about tariff kWhr caps)
https://wallbox.com/en_uk/ev-charging-101
https://futurechargingsolutions.co.uk/bidirectional-storage/#:~:text=The Wallbox Quasar 2 is a bi-directional,mm x 338 mm x 127 mm

DC fast charging is already a thing on commercial installations, but it is very expensive, the AC to DC converters are costly to install, large and just really are not needed in a domestic situation. DC fast changing exists so people can put in a lot of miles in a short amount of time when on a journey, hence 150kW+ chargers, no one needs that speed at home because they are not trying to charge in twenty minutes, neither do you want to regularly fast charge the battery, whilst it is nowhere near as damaging as initially thought it will still accelerate battery degradation (probably cost an additional 5% capacity loss over ten years). Added to which the battery will throttle down the charge speed significantly when over 80% SOC.

Overnight charging should give all but the most extreme drivers, or incredibly inefficient vehicles, so unless people are driving a huge distance every day or drive an electric bus then they really do not need more at home.
7kW = 42kWh = 150-170 miles
11kW = 66kWh = 230-265 miles

pensionpawn said:

born_again said:

pensionpawn said:

I am considering acquiring my first EV next year, which would have an 84 kWhr battery. Having not investigated EV / overnight tariffs in detail, is there a tariff limit (I appreciate that there are electrical considerations) to the amount of kWhrs that can be imported over the 6 hour cheaper period?

Well the good news is unless you are doing long runs everyday. You do not need to charge every day.
So you can just add a % as & when required.

So given IOG new limits you would get 42kW in the 6 hours (subject to some loss)

Well, hopefully 72 kWhrs as the Wallbox Quaser 2 charger is capable of 12 kWs..

Why do you think you need so much power every night?

Bi directional charging (the links..).
I've always viewed EVs as more than just an electrical car. Personally I've never been able to justify the cost of a domestic battery, or an EV, as the ROI can be as long as the warranty and I don't drive enough miles. However an 84 kWhr EV battery, for example, has more capacity than 6 Tesla Powerwall 3's, and with the launch of bi directional chargers, that capacity becomes very handy for more than just driving.
My panels generate ~6.25 MWhrs pa, exporting ~4.2 MWhrs pa. Along with ~ 60-72 Kwhrs of import per night I would not only eliminate all non off peak import, I would also enjoy a healthy export payment as I have a 6 kWs DNO approved limit.
I am aware that a DC bidirectional charger will cost more however I am not in a rush and will wait until they fall from their initial premium price tag (competition will help) and I am fully retired in 9 - 15 months.
As Polestar put it "A future where cars do more than drive"!

MWT

_Sam_ said:

chrisw said:

Some chargers, particularly Ohme, have been throttling charge rates according to conditions. Octopus were seemingly unaware of this and have begun discussions with the charger manufacturers to come up with a solution before the limit is actively implemented.

Zappi could be doing it too (unless it is something that can be changed in settings). At the moment our car is charging but is only getting 6.1kW, while the house is using 4kW. (Then it was first plugged in earlier this morning, the car was pulling 7.4kW which then gradually dropped to 6kW)

Zappi does not have the same issue as Ohme/Hypervolt so that is not the problem you have.

It sounds like you may have your grid limit set too low, as even if you only have a 60A fuse you should be able to pull at least 14kW.

... or your EV is close to 100% full and is throttling back...

matt_drummer

pensionpawn said:

Bi directional charging (the links..).
I've always viewed EVs as more than just an electrical car. Personally I've never been able to justify the cost of a domestic battery, or an EV, as the ROI can be as long as the warranty and I don't drive enough miles. However an 84 kWhr EV battery, for example, has more capacity than 6 Tesla Powerwall 3's, and with the launch of bi directional chargers, that capacity becomes very handy for more than just driving.
My panels generate ~6.25 MWhrs pa, exporting ~4.2 MWhrs pa. Along with ~ 60-72 Kwhrs of import per night I would not only eliminate all non off peak import, I would also enjoy a healthy export payment as I have a 6 kWs DNO approved limit.
I am aware that a DC bidirectional charger will cost more however I am not in a rush and will wait until they fall from their initial premium price tag (competition will help) and I am fully retired in 9 - 15 months.
As Polestar put it "A future where cars do more than drive"!

You intend to `fully' charge the car every night and then use that to power your house and export to the grid?

Won't you kill your car's battery in just a few years?

pensionpawn

matt_drummer said:

pensionpawn said:

Bi directional charging (the links..).
I've always viewed EVs as more than just an electrical car. Personally I've never been able to justify the cost of a domestic battery, or an EV, as the ROI can be as long as the warranty and I don't drive enough miles. However an 84 kWhr EV battery, for example, has more capacity than 6 Tesla Powerwall 3's, and with the launch of bi directional chargers, that capacity becomes very handy for more than just driving.
My panels generate ~6.25 MWhrs pa, exporting ~4.2 MWhrs pa. Along with ~ 60-72 Kwhrs of import per night I would not only eliminate all non off peak import, I would also enjoy a healthy export payment as I have a 6 kWs DNO approved limit.
I am aware that a DC bidirectional charger will cost more however I am not in a rush and will wait until they fall from their initial premium price tag (competition will help) and I am fully retired in 9 - 15 months.
As Polestar put it "A future where cars do more than drive"!

You intend to `fully' charge the car every night and then use that to power your house and export to the grid?

Won't you kill your car's battery in just a few years?

Yes. This is part of the battery design and is very little different to driving 70 miles each way down the M4 to work and back, year after year.... Common sense ensures that the EV has at least 100 mile range remaining every day for that unplanned trip, so it wouldn't be fully discharged. It's also natural that the battery will lose capacity over the years, however if it lost say 20% over 15 years, 60 Kwhrs would still be more than enough to get most people through the day.
It is the natural evolution of the EV, however I'm the first to agree that as adoption increases the increasing demand on the grid transmission capability will become significant with margins narrowing and for those without panels, EV running costs significantly rising.
That's why I'm interested in knowing whether there is currently a kWhrs cap in the small print of time of use EV tariffs.

matt_drummer

1,500 battery cycles in my Tesla is about 500,000 miles.

You intend to do 1,500 cycles in 5 years or thereabouts.

I think you'll kill it and lose more than 20% of range in 15 years.

But that is just my opinion.

Why don't you just read the small print of the ev tariffs you are interested in?

Surely that is much more reliable than relying on the advice of some random stranger on the internet?


Also, tariffs change, as might export payments. Your maths may not work out.

pensionpawn

matt_drummer said:

1,500 battery cycles in my Tesla is about 500,000 miles.

You intend to do 1,500 cycles in 5 years or thereabouts.

I think you'll kill it and lose more than 20% of range in 15 years.

But that is just my opinion.

Why don't you just read the small print of the ev tariffs you are interested in?

Surely that is much more reliable than relying on the advice of some random stranger on the internet?


Also, tariffs change, as might export payments. Your maths may not work out.

Octopus launched their Power Pack bundle with a BYD EV back in June, so they seem fairly confident, as do other EV manufacturers (e.g. Kia, Polestar see FAQs)
I could read all the small print, however I thought I'd enquire in a EV tariff discussion, in the energy board of a money saving website, which I don't quite see as a random internet stranger. Rest assured I'll read the small print before signing anything though!
Yep, tariffs could change (which I alluded to above) and the "business case" weakens. However I'm in the market for a new car regardless in 12 months and for my circumstances the argument for a large battery in an EV with bidirectional charging is overwhelming compared to a domestic static home battery. The worst that can happen is that I buy an EV which, compared to the status quo, minimises my commuting and home energy costs.

QrizB

Pre-order pricing on the Quasar 2 looks to be around $6k in the US. That's likely to become £6k in the UK (which is what the original Quasar cost).

If you're saving 15p/kWh by using V2H then you'll need to cycle 40000 kWh through the battery to cover the wallbox cost. I don't know how much electricity your household uses but that could be ten years or more? It's also like adding an additional 120k miles to the wear level of your battery.

I'm not saying it's a terrible idea, but the economics do need some consideration.