@transparent The background of the ESME design was premised that the ESME would signal the device via ALC/APC, therefore any signal to consume (or stop) would be aligned with the meter's time and ultimately that consumption would fall into the same time windows defined by the meter (inc offset); and therefore billed correctly (from a meter perspective).

The whole reason for the random offset is to avoid killing the energy network (as you stated), this is a very real problem when delaying with large loads like charge chargers.

The problem today is that smart meters aren't the only thing that signals consumption and devices are using 'real' time to do stuff (and if they do stuff exactly at the start of the off-peak period, we're back to square one again with network impact). DESNZ has tried to identify/address this in their Smart Secure Electricity System consultation (currently live), suggesting more regulation is required to make devices have their own random offset (not aligned with meter!?!?)

As I see it, this is a problem for customers who use smart devices independently of ESME signals (which IHMO will be the majority in future) so there must be some way to zero the random offset.

DM me, I'd be happy to raise a modification (my business is a party to the industry code so I can) to the specifications of meters (SMETS) to enable random offsets to be zeroed if the customer requires it, maybe this should be the default unless the supplier has also installed an ALC/APC device. 

Well that didn't take long before this new topic alerted an industry expert !
It's great to see you here @matmbl  😀 

I'm very happy with the SMETS Specification.... but decidedly unhappy that 'later considerations' are getting in the way of it being properly implemented.

Unlike most others here, I can see the effects of large surges and phase imbalance on the grid.
Moreover I have a number of solutions.

But we can't implement those solutions based on the latest whim of DESNZ and Ofgem.
We must build the solutions on the bedrock of the SMETS2 metering system.

From what you've just written, there are two Whims which DESNZ is currently trying to accommodate:

• facilitating 'other devices' to control consumption based on their own understanding of time (most likely UTC)
• adding clauses to the regulatory framework which will require a wider community of randomised offsets

Neither Whim is likely to find much support here on this forum.

@korwraith is an example of many tens of thousands of consumers who are about to discover that they've been systematically over-charged by their Suppliers.
Worse still, that has occurred with the cognisance of DESNZ...
... and the industry regulator allowed it to happen.

This breach of trust is going to undermine whatever DESNZ comes up with from the current Delivering a Smart and Secure Electricity System consultation...
... unless the outcome is to revert to the 2013 SMETS2 Specification of course!

Posted by: @matmbl

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this is a problem for customers who use smart devices independently of ESME signals (which IHMO will be the majority in future) so there must be some way to zero the random offset.

Hmmm. I disagree.

Once the wider public realise that 'smart devices' operating independently of the ESME time periods will

• cost more to run
• retard progress to net zero

... then I think there will be a widespread surge of people wanting to access the Smart Meter scheduling.

It's very important that no one (hint: DCC) even contemplates zeroing the Randomised Offset !

That would be disastrous for the grid, and incur massive expenditure on infrastructure upgrades to minimise the adverse effects of surges.

@transparent

The simplest solution would be for each consumer to be informed of the details of the randomised offset on their particular electricity meter. This would then allow the consumer the choice of starting and stopping devices with timings based solely on UTC, with the knowledge that they will likely be overcharged for their electricity consumption. There may also be additional costs incurred because the grid system may need to be upgraded.

Alternatively the consumer could delay the switching on and off of devices by a value slightly greater than the randomised offset, thereby reducing costs and also helping to reduce possible surges on the local and distant supply networks. People are more likely to choose this option since there is a financial incentive, and once set should not need to be changed.

Consumers should also be encouraged to spread their consumption as much as possible over available hours, which may also help reduce possible surges.

I agree @derek-m  but as I wrote earlier, I don't (yet) understand why the Randomised Offset is included within the secure envelope of the SMETS 2 spec.

The detail that went into writing that spec was immense, and there are usually plenty of obvious reasons for something being defined in a particular way.
So it's very odd to find just one security-related feature where the reasoning eludes me.

If Ofgem is prepared to require all Suppliers to

• inform customers of their Randomised Offset
• populate the tariff matrices

then there's a whole load of clever technology which can built on top of that base

Posted by: @derek-m

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Consumers should also be encouraged to spread their consumption as much as possible over available hours,

Yes. I have a prototype here which calculates that load-spreading for you.

And it's possible to ramp-up and ramp-down the current drawn by a home-device, provided that it has an input port to facilitate that of course.

Although not yet tested, I have also worked out a way to interleave battery chargers which are connected to the same local substation, such that the adverse effects of phase-imbalance can be reduced. The trick is to auto-sense this so that it requires no knowledge or skill on the part of the consumer.

So much is possible once the full SMETS2 spec is implemented.

How come DESNZ can't actually see that?

@transparent not sure I’d call SMETS2 a bed rock, as it’s a specification unique to GB and it’s all up to GB to find the issues and fix them (like this). If we insist globally manufactured devices have the ability to access SMETS2 meters they will get a lot more expensive in this country. But we’re use to that of late!

I’ll not be kicking around in smart metering for much longer (it’s been 10 years for me). If you’d like my help to raise this up, let me know.

Part 5 - Has the Randomised Offset been correctly applied?

In short - No.

Evidence:

DNOs are not permitted access to data from individual Smart Meters.
They receive only amalgamated data, adequate to evaluate transformer loadings at the local substation.

Since losses due to Phase Imbalance is a growing problem, they wanted to undertake additional survey work.

NGED undertook just such a project in Milton Keynes, across 46 local substations.
This work, in collaboration with Loughborough University, used a portable HAYSYS Phase Finder Unit.

This 'sniffer' was used to identify the phase to which individual houses were connected without requiring entry to the property.
A GridKey monitor was attached at the substation end so that demand peaks could be plotted and compared across the phases.

Within their site-work the researchers found time differences between measurements made at the substation transformer and the load being drawn by individual houses. Unaware of the Randomised Offset feature in Smart Meters, they compared the demand-peaks to evaluate the spread of these time differences. The following graph from that report shows the time-shifts for 56 Smart Meters.

This real-world study by NGED’s researchers does not fully correspond with the Smart Metering Equipment Specification (2014).

• the offset is being applied in advance as well as a delay
• the offset can exceed 1799-secs (30mins)

My initial observation is that SM manufacturers have released firmware which doesn't comply with the Specification.

However, Energy Suppliers can also add code to customers' meters and that may have interacted with the Randomised Offset registers.

Posted by: @transparent

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Do you have any evidence that Octopus' billing system (Kraken) takes into account the Randomised Offset to the Tariff Switching Table?
I don't.

To be fair to Octopus, they do have an option to allow smart meter reading every half an hour. It is not entirely clear whether this means they poll the smart meter registers every half an hour or whether this is a "we retain your data to a half hourly granularity". It would be possible to combine that frequency of reading with a knowledge of the offset to bill correctly but does rely on the half hourly reading around the time of tariff transitions to be reliable. With a bit of machine learning pixie-dust could be used to fill in the gaps given past behaviour around the transitions.

A counter-argument to this would point out the existence of the Octopus Home Mini device which forwards smart meter readings over the internet at high frequency (every 10 seconds) and with fairly low latency to be displayed on the Octopus app (30 seconds).

You are correct in your observation @chickenbig 

Several people have worked out their Randomised Offset using a similar method.

Typically they turn on a high-power device like a kettle at times of the day when consumption is otherwise low.
You then compare the histogram bars to determine in which half-hour period that kettle was used.

By moving the time at which the kettle was boiled a couple of minutes later, over a period of days you can get a rough idea as to when your Tariff Periods start.

Posted by: @chickenbig

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To be fair to Octopus, they do have an option to allow smart meter reading every half an hour. It is not entirely clear whether this means they poll the smart meter registers every half an hour or whether this is a "we retain your data to a half hourly granularity".

When I was with Octopus their billing data correlated 1:1 with the half-hourly UTC '30 Minute Interval Reads' shown in my "meter stuff" spreadsheet. I'd fathom they're simply using that data set for their Electric Go billing rather than adjusting the cumulative registers for each customer in line with the customer's random offset. Either is theoretically possible though. And their Intelligent Octopus tariff may operate differently again given that ties in directly with EV chargers and therefore the original purpose of the random offset.

Here's a bill from Octopus showing the half hourly usage, rather than cumulative readings as EDF use, they exactly match my own downloading of my Smart Meter half hourly readings.

Posted by: @korwraith

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their billing data correlated 1:1 with the half-hourly UTC '30 Minute Interval Reads' shown in my "meter stuff" spreadsheet

Yes, that's the point I'm making in this topic.

The Billing being created by our Energy Suppliers correlates 1:1 with the Half-Hour consumption readings.
But it should instead correlate with when a Supplier switches on an EV charger.

These are very difficult concepts to understand, let alone write about here in a Forum!

The great majority of consumers will see that the HH bars on their usage histogram correlate with the bill, and therefore believe that it's correct.
Very few people would have the ability to challenge the accuracy of a bill under these circumstances, and still fewer exchange 38 emails in the course of a complaint!

@korwraith can you please ensure that the information in this forum topic is made available to the member of staff from the Office of the Energy Ombudsman who takes up your case?

When there are systemic failings, the Ombudsman has the capability to report these to Ofgem.

It won't directly affect your case, but it is significant that you have obtained written evidence from EDF that they have been using internal counters within the Smart Meter in an attempt to provide more accurate billing. Their failure to pick up the Randomised Offset means that their attempt didn't work.

However, it is important to note that EDF are basically admitting that were aware of a deficiency in their Billing System and tried to find a solution.
That's the first time I've seen such evidence.
It is more usually the case that Energy Suppliers either don't understand the nature of their customer's complaint or else try to cover it up.

EDF's stance may still be 'wrong' but their attempts to provide 'fair billing' may yet save them from severe financial penalties for breach of licence conditions.

Posted by: @transparent

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@korwraith can you please ensure that the information in this forum topic is made available to the member of staff from the Office of the Energy Ombudsman who takes up your case?

I have provided them with a link to this discussion and suggested that they may wish to escalate to Ofgem.