Smart Meters and Economy 7

[mikemillar]

Has anyone with an economy 7 meter and heavy off peak usage, like an electric car, (or storage/under floor heating) had a smart meter fitted? Quite a lot of newer tariffs only seem to provide 4 hours or other off-peak electricity.

I frequently charge for 4 hours or more and also have immersion heaters coming on in the early morning so I need the full 7 hours off-peak rate to be available. I understand that smart meters can be set to 7 hours off-peak, but presumably that is controlled remotely by the supply company. I assume they do that if one opts for a tariff with shorter off-peak hours.

I could get slightly lower tariff rates if I opt for a tariff which requires a smart meter to be fitted. What worries me is that I may then be forced to accept a shorter off-peak time and they may set it remotely without my permission. Also, E7 tariffs might become very scarce, more expensive or unavailable in the future. I suspect that the whole charging structure may change in the future anyway and there's not much we can do about that. Any info or thoughts appreciated.

 

[Epico]

Has anyone with an economy 7 meter and heavy off peak usage, like an electric car, (or storage/under floor heating) had a smart meter fitted? Quite a lot of newer tariffs only seem to provide 4 hours or other off-peak electricity.

I frequently charge for 4 hours or more and also have immersion heaters coming on in the early morning so I need the full 7 hours off-peak rate to be available. I understand that smart meters can be set to 7 hours off-peak, but presumably that is controlled remotely by the supply company. I assume they do that if one opts for a tariff with shorter off-peak hours.

I could get slightly lower tariff rates if I opt for a tariff which requires a smart meter to be fitted. What worries me is that I may then be forced to accept a shorter off-peak time and they may set it remotely without my permission. Also, E7 tariffs might become very scarce, more expensive or unavailable in the future. I suspect that the whole charging structure may change in the future anyway and there's not much we can do about that. Any info or thoughts appreciated.

This thread covers it

UK Electricity Tariffs for EVs

 

[discoM3]

Good question and also interested to know the answers.

I am contemplating an Eco7 meter being installed and wondered what would happen if a Smart meter was later installed.

I kind of hoped that if i paid to have the Eco7 meter installed, they would just take the opportunity to install a smart meter capable of Eco7 data. It seems backwards to install a new manual meter?

 

[Roy W.]

When we had E7 installed for the Leaf in 2015 we already had a smart meter, dating from 2011. Of course is wasn’t E7 compatible, so out it came and a manual, dual rate meter went in.

British Gas then wanted to put a smart meter in back in 2016, and I got as far as the fitter coming on the appointed day, only for her to come from the meter cupboard and say “But you’ve got Economy 7! We don’t do a smart meter that will do Economy 7!”

Roll on to 2017 and I went to OVO. They installed a dual rate smart meter within a few days of me joining them.

I’m now with Octopus GO, and the meter that OVO installed is compatible with Octopus, so happy days.

You shouldn’t have to pay to have your meter changed it it’s being changed to work with your new supplier/tariff. You certainly can hold off, but smart meters are here, and I’m sure in the long term anyone without a smart meter will be pressured into having one fitted, most probably by punitive non-smart tariffs.

 

[mikemillar]

This thread covers it

UK Electricity Tariffs for EVs

Thanks Epico, I've just looked back at at lengthy thread, which I'd posted on the end of without reading all of it. There is quite a bit about smart meters there, but I don't really think it answers my basic question, which is:

Who controls the length of the off-peak period? Me (via the tariff I choose), or the supplier?

 

[mikemillar]

British Gas then wanted to put a smart meter in back in 2016, and I got as far as the fitter coming on the appointed day, only for her to come from the meter cupboard and say “But you’ve got Economy 7! We don’t do a smart meter that will do Economy 7!”

Thanks Roy, interesting. But I suppose that with the SMETS2 meters they can do it now? Anyone on E7 with a SMETS2 meter, or even a SMETS1?

 

[mikemillar]

You certainly can hold off, but smart meters are here, and I’m sure in the long term anyone without a smart meter will be pressured into having one fitted, most probably by punitive non-smart tariffs.

I'm sure you're right in the long term, Roy. Quite how long that is who knows. It might be shorter than we think. But there must be quite a lot of people with night storage heaters, or electric under floor heating, probably often poorer people too, who depend on the 7 hour E7 rate, or even the E10 rate being not too expensive. They could be hit hard with shorter off-peak smart meter rates.

I'm just trying tho cover my options for the reasonably foreseeable future.

 

[Roy W.]

Who controls the length of the off-peak period? Me (via the tariff I choose), or the supplier?

The actual control is with the supplier. But you effectively choose the off-peak period through your tariff choice. That means that if things change in the future your supplier could change the off-peak window. In practice though, I’ve never known that. Unless you’re on a fixed-term deal, which by definition has an end date, suppliers will normally leave you on a legacy tariff even if it is long discontinued.

The main point for me is that if things happen I don’t like, I’ll simply jump ship to another supplier. If they’re all applying the same changes, then I think you’re stuffed whoever you’re with!

 

[Roy W.]

I'm sure you're right in the long term, Roy. Quite how long that is who knows. It might be shorter than we think. But there must be quite a lot of people with night storage heaters, or electric under floor heating, probably often poorer people too, who depend on the 7 hour E7 rate, or even the E10 rate being not too expensive. They could be hit hard with shorter off-peak smart meter rates.

I'm just trying tho cover my options for the reasonably foreseeable future.

Absolutely, I fully understand.

Unfortunately EVs may well change what becomes defined as off-peak. We’re going from a situation where we’re all asleep, and the network is awash with power, to a time when we’ll all have our EVs plugged in charging, making for huge demand.

By then I’m hoping that a lot of that change will be mitigated by more PV rooftop solar, battery storage, and eventually vehicle-to-grid.

 

[mikemillar]

The actual control is with the supplier. But you effectively choose the off-peak period through your tariff choice.

Thanks Roy. I think that's the answer I'm looking for. It's roughly what I thought might be the case, but it's not exactly clear on any of the electricity quote sites. They don't even state the off-peak period, although I suppose if you select an E7 tariff you are going to get 7 hours.

 

[Roy W.]

Thanks Roy. I think that's the answer I'm looking for. It's roughly what I thought might be the case, but it's not exactly clear on any of the electricity quote sites. They don't even state the off-peak period, although I suppose if you select an E7 tariff you are going to get 7 hours.

The off-peak period is a strange one. It definitely varies from supplier to supplier, but with OVO it also varied depending on your location. Strangely, also with OVO, despite it being a smart meter, it also changed with the clocks in March and October. Complicated!

With Octopus GO it is a fixed 4 hour window, from 0030-0430 every day.

With that charging at 5p/kWh I’m hoping to get my M3 running cost down to close to 1p per mile.

 

[mikemillar]

Absolutely, I fully understand.

Unfortunately EVs may well change what becomes defined as off-peak. We’re going from a situation where we’re all asleep, and the network is awash with power, to a time when we’ll all have our EVs plugged in charging, making for huge demand.

The thought crossed my mind as well while I was writing my post, but I didn't want to complicate the issue. Millions of EV's charging at night will certainly have a major impact on the grid. Interesting times....

 

[MrBadger]

By then I’m hoping that a lot of that change will be mitigated by more PV rooftop solar, battery storage, and eventually vehicle-to-grid.

Noooooooo.

V2G is likely to become a problem waiting to happen imho.

Sounds good in theory, but I am personally of the opinion that batteries optimised for cars should be used to power cars and not to power other peoples wasteful practices.

If you want to use a battery to power a home, then use a battery designed to power the home, not a car.

I do not think at the moment there is enough reliable data to know what the effect V2G and V2H will have on a car battery. I know some people claim that it will only be a small amount, but it may still affect the lifespan of an EV battery. A few trials with home battery storage to grid taking place at the moment - quite a few battery units are having to be replaced within a short space of time. It doesn't help that many of these trial units have a small capacity so are possibly being damaged by deep discharge and significant recharge cycles, but it still indicates that this all takes a toll on things.

Much better if dedicated home storage became more affordable (or even economical) and waste was penalised.

imho.

 

[tonyj01]

. Millions of EV's charging at night will certainly have a major impact on the grid. Interesting times....

The cars will move to smarter charging so that all the “devices” attached to the grid will take power in a balanced way.

Eg a smart freezer doesn’t need power on 24/7 it can have 15 or 30 minutes without drawing from the mains. Imagine 10 million freezers that can be controlled, that also frees more power when millions of cars need the power.

Back to the OP. Bulb Energy offer great rates for E7 www.bulb.me/anthonyj7176

Regards, Tony

 

[Rob R]

Noooooooo.

V2G is likely to become a problem waiting to happen imho.

Sounds good in theory, but I am personally of the opinion that batteries optimised for cars should be used to power cars and not to power other peoples wasteful practices.

If you want to use a battery to power a home, then use a battery designed to power the home, not a car.

I do not think at the moment there is enough reliable data to know what the effect V2G and V2H will have on a car battery. I know some people claim that it will only be a small amount, but it may still affect the lifespan of an EV battery. A few trials with home battery storage to grid taking place at the moment - quite a few battery units are having to be replaced within a short space of time. It doesn't help that many of these trial units have a small capacity so are possibly being damaged by deep discharge and significant recharge cycles, but it still indicates that this all takes a toll on things.

Much better if dedicated home storage became more affordable (or even economical) and waste was penalised.

imho.

On the contrary I think V2G is a solution to a problem waiting to happen, that problem being the smooth functioning of the national grid. Imagine 20 million batteries contracted to take or supply electricity instantly into the grid. Let's say 10 kWh average. That's 200 gigawatt hours worth of nuclear power stations you don't need. Instant on, instant off, controlled by an algorithm. That will stabilise all the renewables you care to throw into the mix.
The effect on the car battery is not totally clear, but early indications are that it may improve battery life. Running a car is a very hard job for a battery, constant changes in demand and extreme demand being the main issues. Supplying the grid will be r&r for the battery, easy duty, a nice rest. I am sure car manufacturers will input into the V2G contracts let, so the car does not suffer. Then those contract terms regulate the algorithm, so everybody wins.
We are a long way away yet, but I see this as hopeful, not worrying at all.

 

[mikemillar]

Noooooooo.

V2G is likely to become a problem waiting to happen imho.

Sounds good in theory, but I am personally of the opinion that batteries optimised for cars should be used to power cars and not to power other peoples wasteful practices.
imho.

I’m inclined to agree. According to a friend who has some contact with a Telsa director, the car battery chemistry is optimised for very high output/input (acceleration/supercharging) combined with good battery life. Powerwall batteries, on the other hand, don’t have these very high output/input requirements and the chemistry is optimised for longer battery life. I don’t know how correct this is but he advised don’t do it even if you can as it will shorten the car battery life. In any case, using the car battery to supply the grid or house will result in a larger number of charge/discharge cycles, which also reduces the battery life. I wouldn’t risk my Model S battery life to get a small income from the grid. I intend to keep it for a long time, particularly with free supercharging for life.

The two power companies who are currently paying for export to the grid are paying a pittance for it, about 4p/kWh, which is rather less than we can buy off-peak electricity for. If they paid a decent rate for export at high demand times it might be a different matter.

National Grid currently import a lot of electricity via the French and Dutch Interconnectors – 2.4GW as I write this
G. B. National Grid status
I wonder what they pay for that. I think they only buy when the French/Dutch have a surplus and the price is low.

 

[Roy W.]

...using the car battery to supply the grid or house will result in a larger number of charge/discharge cycles, which also reduces the battery life.

I don’t think the idea of charge/discharge cycles really applies to EV batteries, in the same way it does to, say, a mobile phone. When you’re driving the regenerative braking is constantly switching in to charge the battery whenever you slow down, then immediately you accelerate the battery will discharge again. These aren’t really the same as charge/discharge cycles.

 

[ItsNotAboutTheMoney]

On the contrary I think V2G is a solution to a problem waiting to happen, that problem being the smooth functioning of the national grid. Imagine 20 million batteries contracted to take or supply electricity instantly into the grid. Let's say 10 kWh average. That's 200 gigawatt hours worth of nuclear power stations you don't need. Instant on, instant off, controlled by an algorithm. That will stabilise all the renewables you care to throw into the mix.
The effect on the car battery is not totally clear, but early indications are that it may improve battery life. Running a car is a very hard job for a battery, constant changes in demand and extreme demand being the main issues. Supplying the grid will be r&r for the battery, easy duty, a nice rest. I am sure car manufacturers will input into the V2G contracts let, so the car does not suffer. Then those contract terms regulate the algorithm, so everybody wins.
We are a long way away yet, but I see this as hopeful, not worrying at all.

As JB Straubel has said, 90% of the benefit of V2G is actually in smart charging (G2V), which will be a necessary good with a high penetration of PEVs. Smart charging is a software problem that with works with the current electricity system, without a change in associated hardware.

Addressing the other 10% could be done with V2G, or it could be done with dedicated storage. The advantage of V2G is in using existing batteries, while the advantage of static storage is ease of management.

I think that PV and battery cost reductions will push towards dedicated storage. It might be that car batteries will be used for input, but with banks of used car batteries, rather than banks of cars. In the long term, I expect to see batteries going more directly into the recycling stream.

 

[mikemillar]

I've just found this rather sobering statement while looking into the question we are discussing:

"The EV battery also ages and the capacity fades, but the EV manufacturer must guarantee the battery for eight years. This is done by oversizing the battery. When the battery is new, only about half of the available energy is utilized. This is done by charging the pack to only 80% instead of a full charge, and discharging to 30% when the available driving range is spent. As the battery fades, more of the battery storage is demanded. The driving range stays constant but unknown to the driver, the battery is gradually charged to a higher level and discharged deeper to compensate for the fade"​

Source: Why Mobile Phone Batteries do not last as long as an EV Battery – Battery University

Perhaps congratulating myself that I've only lost 3% in 50K miles is premature. Might explain why people are suggesting that the Model S battery, and the Powerwall, have a hidden reserve you can't access.
Can't help feeling we're getting slightly off topic here.....

 

[mikemillar]

I don’t think the idea of charge/discharge cycles really applies to EV batteries, in the same way it does to, say, a mobile phone. When you’re driving the regenerative braking is constantly switching in to charge the battery whenever you slow down, then immediately you accelerate the battery will discharge again. These aren’t really the same as charge/discharge cycles.

Of course the same applies to a Powerwall to a degree - at least in the UK! - when it's set to charge from solar it tends to charge and discharge small amounts quite frequently as the sun goes behind clouds. While charging from the grid is fairly constant, discharging to the grid with V2G (or P2G?) could be quite eratic if some form of intelligent control is exercised.