Posted by: @transparent

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Posted by: @jeff

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new EV charger regulations have a randomised up to  10min delay on any schedule you set (can be overridden), and that this can be increased to up to 30min by energy suppliers

Where are those 'regulations' published @jeff ?
These must surely have been agreed in discussions with Ofgem.

To allow the Energy Supplier to alter your settings means that they must be sending commands across the internet, as opposed to using the features within our Smart Meters.

The original Smart Meter spec from 2013 stipulates that all electricity (and gas) meters must have randomised numbers placed within them at the time of manufacture.
Those numbers are used within the firmware algorithms to define when your charging periods start.
Moreover, the mechanism by which this achieved must itself be encrypted and protected to prevent it being analysed.

For an electricity meter the algorithm creates a delay (post-UTC) of up to 1799 seconds.

The 'tech' may work together seamlessly, but I can't see how the bills can be correct.

The Energy Suppliers are unable to interrogate a Smart Meter to ascertain the randomised delay, precisely because the spec states that such data is protected.

I do understand why this is so.
It relates to the security of the UK Energy Supply.
I'm obviously not going to describe the nature of the threat here on an open forum!

I believe it is very unwise for Ofgem to have agreed to a workaround under these circumstances.
Whyever hasn't NCSC stepped in to overrule them?

New regulations came in last year and then 1st Jan for some follow-up. 

https://www.gov.uk/guidance/regulations-electric-vehicle-smart-charge-points

Quite a bit has been written about them, for example 

https://pod-point.com/guides/smart-charge-point-regulations

You would have to dig deeper to see what is meant by energy companies and what mechanism is used to increase to 30min.

Perhaps you could summarise what you think is important in these regs? Have you already read these new regs? 

2. Randomised delay

Alongside the default charge schedule, chargepoints also need to randomise the start or end of a charging session by up to 10 minutes*.

This measure is for protecting the grid and local substations from instantaneous surges in demand, such as at the beginning of the default schedule when everyone’s chargepoint activates and their EVs start charging. Similarly, it prevents unexpected surges like after a power outage or loss of internet connection.

Instead, the demand is spread out with a random delay of up to 10 minutes*, meaning your charger may not start or end its charging session immediately.

This could result in you losing out on a few minutes of a lower electricity rate, but it’s necessary to protect the energy grid and keep EVs charging reliably.

*This could be increased by up to 30 minutes by energy companies, although we’re yet to see any indication of any intent to make use of a longer delay.

Posted by: @jeff

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This measure is for protecting the grid and local substations from instantaneous surges in demand

That's why the BEIS Team devised the random number system for our Smart Meters 9 years ago!

Energy Suppliers seem very concerned to use the internet rather than send commands across the mechanism which already exists for precisely this purpose!

Yes I have raised this with senior figures in Supplier companies, and I've heard their responses.

Their argument is that the National Smart Meter Network is designed to handle data at half-hourly intervals.
But they require analytical data/feedback from EV Smart chargers on a minute by minute basis.

I still think they've confused two separate matters.

The Start/Stop Commands to EV's (and other forthcoming LCT devices) should be sent via the Smart Meters, as originally specified.
That doesn't prevent the Suppliers from also retrieving data from those same chargers across the internet.

Posted by: @transparent

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Quite @derek-m !

In fact, those of us with storage batteries and an appreciation of how electricity demands are made, could readily configure them to 'look like' an EV charger or a heat-pump as far as our Energy Supplier is concerned. 🤔 

The actual objective of the cheaper overnight tariffs is not to reward groups of electricity users, but to help reduce the number of electricity generating units that need to actually stop generating and shutdown, then restart again in the morning. Shutting down and restarting large generators not only costs money but may also waste energy, so if the power station operator can get away with just reducing load and selling the electricity produced at cost or slightly under cost, it could be financially beneficial for them.

It can also help balance the supply and demand on the electricity grid, since if people are charging their EV's, or home batteries, or even running their heat pump to produce hot water, during the lower demand overnight period, then they are less likely to do so during the higher demand daytime period.

Homeowners should therefore be encouraged to move demand from the daytime to the nighttime period. The only caveat is that if everyone moves their demand from daytime to nighttime, they may then find that the cheaper overnight tariffs quickly disappear. 🙄 

@transparent you make some very valid points. OK, I was hasty. I have crunched some numbers, and looked more in detail at the Octopus Cosy tariff product. It will save me money. I cannot say exactly how much, but I estimate a few hundred pounds a year. The standard rate cost is comparable to my current tariff with Ovo.

Where I will benefit is in the winter months as a higher consumer with only electricity as an energy and ASHP heating and hot water. I have 3.6kW Solar PV with 6.5kW battery storage. The battery doesn't do much in winter as the Solar PV doesn't generate that much, and stays mostly in a discharged condition. I can set charge times to coincide with the Cosy lower rate tariff periods and then draw on that power during standard and peak rate tariff times. The two charging periods a day works better with a smaller battery. I would need substantially more battery storage capacity to take advantage of low overnight charging tariffs. I've allowed for battery and inverter efficiency and maximum 90% battery discharge in my calculations.

So, in a U-turn worthy of a Conservative Government policy, I've just signed up to Octopus Flexible and will then apply for Cosy! 😀

Posted by: @derek-m

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Homeowners should therefore be encouraged to move demand from the daytime to the nighttime period.

Is this the moment when I should be posting examples of underground supply cables over-heating due to the increasing number of EV-chargers?

Our 440v local distribution cabling was installed when it was expected that cables could heat up during the evening.
They would cool down again overnight due to sitting in damp soil.

That's soon not going to be true.

@allyfish

Made me smile about the U turn 😆.

We've saved £5.29 in 3 days loads shifted lots. It's all new to me so have had to set reminders to turn things on to charge and set washer/dishwasher to come on at 4am.

But best thing is I don't have to sit through The Chase at 5pm with hubby 🤣 like Bradley but humanity gets on my nerves.

Posted by: @transparent

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Posted by: @derek-m

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Homeowners should therefore be encouraged to move demand from the daytime to the nighttime period.

Is this the moment when I should be posting examples of underground supply cables over-heating due to the increasing number of EV-chargers.

Our 440v local distribution cabling was installed when it was expected that cables could heat up during the evening.
They would cool down again overnight due to sitting in damp soil.

That's soon not going to be true.

Did they not allow for global warming and everyone having EV's and battery storage when sizing the cables? 🙄 

Obviously there will be situations where moving demand from daytime to nighttime during short time periods will not be beneficial, which will be one of the reasons why DNO approval becomes necessary.

The rapid transition, in electricity system planning terms, from gas, coal, oil and petrol to electricity, is far from ideal. One doesn't need to be a Nobel Prize Winning Physicist to realise that anyone with more than 2 brain cells will move as much electricity demand to the cheaper tariff periods if it makes financial sense to do so.

The excess demand may be particularly acute in rural areas, where it is possible the overnight demand could increase from a few hundred watts per household, to 10kW or even 20kW per household. It may be necessary in such circumstances for the cheaper tariff period to be staggered for different users in the same area, or we could get to the point where there are no longer cheaper overnight tariffs. 😪 

Maybe in a few years time the government will be encouraging everyone to trade in their EV for a diesel or petrol vehicle? 🙃 

OK, first full monthly billing period with Cosy Octopus, and, combined with a 6.5kWh battery charged at cheap rate periods, it has saved me 25% compared to my Ovo standard variable rate tariff. Fair play Octopus, it's a good product which I'm really seeing a benefit from. Even with a round trip charge/discharge cycle of about 90% efficiency and my battery for some reason, sometimes taking an hour's extended tea break when discharging. (Maybe a thermal control thing to prevent too high a current drain for too long)

Having spent all day reading copious info, a lot of it very useful stuff from this forum, looking up a variety of stats and making guesstimates for the ASHP that I don’t even have yet I’ve concluded that with my 4kw pv and 10kw battery (which I’ve only had for 6 months) and proposed 10kw ASHP based on my annual gas use of 15kwh and being the owner of a plug in hybrid car then switching to Cosy is…impossible to tell but probably almost exactly the same as sticking with Go!  

if in a year’s time I think any different I’ll report back 😂 and if anyone thinks different based on their own experience please let me know!

There are a number sticking points with devising tariffs, any of which could suddenly be resolved.

• The buy-in (wholesale price) paid by Suppliers depends on archaic rules which they don't want changed.
• Ofgem has yet to tell Suppliers that they must all offer at least one variable-rate (Time of Use) tariff
• Ofgem allows Octopus to issue as many ToU tariffs as it wants, but restricts Suppliers to only 3 fixed-rate tariffs.
• National Grid and Ofgem are both wanting us to move to Nodal Pricing. That adds a further layer on top of ToU pricing, in that it will also vary according to your location
• In April, Ofgem brought in a new formula to allow renewable energy generation companies to be offered connection to the Distribution Grid (<132kV) without paying any contribution towards the cost of infrastructure upgrades to facilitate that connection. As a result, regions that are already generating surplus electricity are now receiving yet more connection applications 😖 

A change of Government could introduce policies which affect any or all of the above.

@noob may not have to wait a year before re-evaluating the viability of Octopus' tariffs.

@noob Nope, I have a similar setup to you (full EV rather than PHEV is the main difference I think) and it's the same for me. Flux in summer and Go in winter makes most sense.

Hi all, crunching year end numbers. I'm on 'Cosy Octopus' 3 tier tariff, and in the winter heating season I schedule charge my 13kW of solar PV battery storage on the cheapest tariff. This is between 4am-7am and 1pm-3pm daily. The solar PV isn't doing much in winter, but the batteries can be made to work to my advantage. The vast majority of my energy consumption is Nov-March when the ASHP heating is on all day every day. By schedule charging, 88% of my monthly consumption is on the cheapest tariff, 9% on the standard tariff, and 3% on the peak rate tariff. The average incl. VAT and standing charge is 21.76p/kWh. Octopus standard flex tariff is 30.62p/kWh. Not a large difference you might think, but at 5000kWh/annum imported consumption that equates to £443 a year, an annual electricity bill saving of 29%.