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If it works anything like as reliably as the rest of the smart metering system, there should be no concerns any time soon. The first question is who owns the switch? Physically it is the property of the meter operator but it’s controlling a product sold under a contract with an electricity supplier and the most likely user of the switch in the case described is the DNO.

The next problem is reconnecting the supply. In the event of a power cut, the DNO could legitimately claim that it was beyond their control but if you deliberately disconnect a customer and they sustain damage or injury when you reconnect then you cannot claim that defence.

Personally I think that remote disconnection of individual domestic customers is a lot of trouble for a once in ten year event, especially as the required security seems to be behind a lot of the issues that have dogged the roll out. As was demonstrated in the August ‘19 event, applying DSR to large customers can restore frequency. What would have made the event less noteworthy is a bit of decent reliability engineering by a certain German train manufacturer.
This document bears all the hall marks of lobbying by the DNOs so they do not have to improve the local distribution networks to cope with a changing market and a redesign with new diversity factors. I cannot imagine the domestic electricity suppliers want to lose out on the opportunities to sell more electricity at times when it can be expensive.

It is the issue of who pays for local distribution network upgrades for domestic consumers being kicked down the road yet again. The changes needed for mass adoption of EVs are not huge in comparison with the new load that would come with a switch from gas to heat pumps for domestic heating compounded as it would be by a very high peak demand in cold weather juts when the heat pumps have their worst Coefficient of Performance.

On another note has anybody spotted the perfect places for large scale battery grid storage farms for balancing and stability are the brownfield sites in the Midlands of former coal fired power stations that already have grid power lines feeds on site. Reuse what we already have.
 

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This is just a logical extension of the system that has been in place for years for larger commercial/industrial supplies, where users contract on the basis of a tariff versus priority basis.
Yep, at least since 1976 when I joined the ESI and not sure how many years previously. If everybody is sensible there shouldn't been many occasions to call on the tool, but people can either pay for loads of redundant plant with all the capital costs involved, or they can reduce consumption temporarily. The great diversity of users helps in this respect, and informed users even better. That is what Agile has all been about. If you don't need to charge your car then don't. For every Stageshoot there are thousand of us where a charge a week suffices. Those of us with solar panels already exercise common sense as to when we do certain things.
 

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In france we can chose the level of our home supply in steps 6kva, 9,12,15,18 etc according to our likely useage.
In Italy my flat had a 3kW (!) supply, which actually tripped at 3.3 and then had to be reset as Paul describes. I tripped the supply only around half a dozen times in 7 years, so it's a learning process. I knew enough not to have a powerful English electric kettle for my cuppa!
 

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I'd think it would be far better to build it into car charging firmware. If voltage drops then the car should slow down the charge rate for a while. It's far less crude than specific hours.
Be really good to have some joined-up thinking sometimes, rather than this muddled, one step forward, one step backward, process that seems to dog government initiatives.
Team effort - Speak EV has enough folk with real experience and knowledge to do it better than the Govt dept drones listening to the loudest lobby of the moment.

So a starter idea for 10.

A Smart EVSE detects when the supply frequency is dropping into the front edge of the band that requires voluntary disconnections. It then disconnects charging and the car records the event. Supply frequency is monitored and when recovered for a reasonable period reconnects charging. No comms outside the EVSE is required. No standby consumption until the recovery phase after a disconnect during charging. Users of these EVSEs get a small rebate every month for accepting disconnect on car charging as a first stage network protection agreement. Smarter than turning off the house supply as somebody's home kidney dialysis machine is unlikely to be connected to the circuit for the EVSE. :)
 

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You would need to reduce the charge rate rather than disconnect for that to work. Once disconnected, the car has no way to see when the frequency recovers.
 

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You would need to reduce the charge rate rather than disconnect for that to work. Once disconnected, the car has no way to see when the frequency recovers.
That's why it's better the car reduces charge rate as it won't choose one it can't do. Plus many connected cars can send a notification that it's slower than usual. If you have a scheduled departure it shouldn't keep it so low the vehicle won't be charged to the needed level by the needed time. If the system is trust worthy then folk won't over ride it and just fit dumb chargers. I can't imagine employers being fine with employees being late because the car didn't charge enough.
 

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Yes you can, we have just switched to one. We pay 7p/kWh for 7 hours every night, on an EV tariff, with no smart meter, just an ordinary Economy 7 meter.
Would you mind sharing who that tariff is with? I’d love to find an e7 tariff as low as that for our storage heaters!
 

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You would need to reduce the charge rate rather than disconnect for that to work. Once disconnected, the car has no way to see when the frequency recovers.
It would be the EVSE that sees frequency has recovered and reconnects supply to the car.
 

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Would you mind sharing who that tariff is with? I’d love to find an e7 tariff as low as that for our storage heaters!
If your storage heaters have an EV registration plate then it could be a go. Good Energy EV tariff.
 

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Would you mind sharing who that tariff is with? I’d love to find an e7 tariff as low as that for our storage heaters!

As above, Good Energy EV tariff, fixed tariff until June 2023. I can give you a referral that gets us both £50 if you wish. . .
 

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Despite being pretty typical Mail crap, it is worth remembering that this is precisely why the OZEV grant is only available for smart charge points. The whole idea, although really badly implemented, was to allow charge points to be remotely disabled at times of high grid demand. There was no other logical reason for making the grant dependent on charge points being internet connected. It's exactly the same reason that every single smart meter has a remote disconnect contactor, so that if things get tight then consumers using a lot of power can just be turned off for a time.
Surely the first step is to scale back charging rates?
Reduce the charger to 24A or 16A during peak times and you'll take a lot of the strain off the grid.
 

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This document bears all the hall marks of lobbying by the DNOs so they do not have to improve the local distribution networks to cope with a changing market and a redesign with new diversity factors. I cannot imagine the domestic electricity suppliers want to lose out on the opportunities to sell more electricity at times when it can be expensive.
(y)
 

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I'd think it would be far better to build it into car charging firmware. If voltage drops then the car should slow down the charge rate for a while. It's far less crude than specific hours.
I see that the debate here has moved on to exactly this. However - it's frequency, not voltage, that needs monitoring. Local voltage fluctuations could be caused by all sorts of things, and it's common for the voltage to vary with time of day / local load conditions. Frequency dropping is the indicator of concern.
 

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That's why it's better the car reduces charge rate as it won't choose one it can't do. Plus many connected cars can send a notification that it's slower than usual. If you have a scheduled departure it shouldn't keep it so low the vehicle won't be charged to the needed level by the needed time. If the system is trust worthy then folk won't over ride it and just fit dumb chargers. I can't imagine employers being fine with employees being late because the car didn't charge enough.
Isn't this sort of smart charging what Jedlix is trying to do? If there's too much demand on the grid then that could stop the car charging, but still ensure it is charged to the required level by the required time. All software via car API.
 

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As above, no point using the charger to measure frequency and modulate, the only sensible way to do this is to measure frequency at the always connected charge point and either reduce the maximum advertised current, or terminate/disable the charge if the frequency dips below the first load shedding threshold (off the top of my head I think this is around 49.5 Hz for more than the threshold time - someone with grid management experience can probably clarify the exact load shedding trigger frequency points). By the same token, charge points could modulate the advertised charge current upwards, if they are being curtailed, if the frequency increases, as increasing demand lowers frequency.
 

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As above, no point using the charger to measure frequency and modulate, the only sensible way to do this is to measure frequency at the always connected charge point and either reduce the maximum advertised current, or terminate/disable the charge if the frequency dips below the first load shedding threshold (off the top of my head I think this is around 49.5 Hz for more than the threshold time - someone with grid management experience can probably clarify the exact load shedding trigger frequency points). By the same token, charge points could modulate the advertised charge current upwards, if they are being curtailed, if the frequency increases, as increasing demand lowers frequency.
It is 49.5 Hz for the lower limit for normal operation. At 48.4 Hz it is becomes compulsory automated disconnection if there is no time to try voltage reduction first to bring the frequency back up. Finally generation should not trip until 47 Hz. So a window of 49.5 to 48.4 Hz for voluntary disconnection or stepping down from 7 kW to 3.6 kW charging. Curtailing has a specific meaning in this context. It is when a generator is shut down because the distribution system lacks capacity to transport the generated output.
 

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As above, no point using the charger to measure frequency and modulate, the only sensible way to do this is to measure frequency at the always connected charge point and either reduce the maximum advertised current, or terminate/disable the charge if the frequency dips below the first load shedding threshold (off the top of my head I think this is around 49.5 Hz for more than the threshold time - someone with grid management experience can probably clarify the exact load shedding trigger frequency points). By the same token, charge points could modulate the advertised charge current upwards, if they are being curtailed, if the frequency increases, as increasing demand lowers frequency.
This is a principle known as dynamic demand and quite frankly I'm surprised it's not used too much.

About 10 years ago I recall a number of electricians and electronic engineers were pushing for it to be implemented in mainstream appliances.

Put simply things like: if frequency is below X Hz, then delay a cycle by X minutes. For the fridge it could allow the temperature to raise 1-2 degrees higher than normal, for the dishwasher it could pause the water heating and extend the rinse, for the washing machine it could suspend the spin cycle -- Little things would all help to stabilise the grid if the load was going in the wrong way and therefore reduce the need for frequency stabilisation. Since many of these devices contained microcontroller-based triac controls with phase-synchronised firing, it would be possible to implement with software in most cases.

One step further would be for the grid to have a few nominal frequencies that would be used to signal events, e.g. nominal 49.8Hz+/-0.1Hz is "eco-mode" whereas 50.2Hz+/-0.1Hz is "excess supply: run now". Of course you'd need to ensure these periods averaged out to 50Hz to keep clocks in sync, so the real-world implementation might be more difficult.
 

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This is a principle known as dynamic demand and quite frankly I'm surprised it's not used too much.

About 10 years ago I recall a number of electricians and electronic engineers were pushing for it to be implemented in mainstream appliances.

Put simply things like: if frequency is below X Hz, then delay a cycle by X minutes. For the fridge it could allow the temperature to raise 1-2 degrees higher than normal, for the dishwasher it could pause the water heating and extend the rinse, for the washing machine it could suspend the spin cycle -- Little things would all help to stabilise the grid if the load was going in the wrong way and therefore reduce the need for frequency stabilisation. Since many of these devices contained microcontroller-based triac controls with phase-synchronised firing, it would be possible to implement with software in most cases.

One step further would be for the grid to have a few nominal frequencies that would be used to signal events, e.g. nominal 49.8Hz+/-0.1Hz is "eco-mode" whereas 50.2Hz+/-0.1Hz is "excess supply: run now". Of course you'd need to ensure these periods averaged out to 50Hz to keep clocks in sync, so the real-world implementation might be more difficult.
So when the grid is above 50 Hz (running light) allow 7 kW charging and when below 50 Hz reduce to 3.6 kW charging. This would track actual peak and light load events based on balance between generation and consumption instead of a time schedule based on demand peaks only. Yields high probability of 7 kW in silent hours but some charging at all times unless the grid is going out of normal limits. Apply the same to 11 and 22 kW three phase EVSE when 3 phase becomes the standard domestic connection for new builds without gas.
 

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If your storage heaters have an EV registration plate then it could be a go. Good Energy EV tariff.
Could try and get a plate for the heaters I suppose ;) but probably not needed as my EV has that bit covered!

As above, Good Energy EV tariff, fixed tariff until June 2023. I can give you a referral that gets us both £50 if you wish.
I’ll look into it this week and let you know if I will use a referral. Thanks both.
 
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