Posted by: @scrchngwsl

[tariffs] what limits me from taking full advantage of them is that nothing talks to each other. The battery/inverter, EV charger, and ASHP don't know about each other, so I have to do a lot of manual optimising...

That's an extremely important observation. Each manufacturer is creating their own interface and control mechanism without regard to the others.

It's an issue I'm actively researching, and it has implications for the accuracy of our bills and the security of our electricity supply in GB. I've been documenting such weaknesses over the past year and discussing remedies with local Councillors and my MP.

The potential for such problems was identified in 2013 when the design specification for Smart Meters and the National Smart Meter Network were laid down.

Our tariff gets downloaded into the Communications Hub, bolted on top of the Smart Electricity Meter (ESME). Each Comms Hub keeps its own time, set during manufacture and offset randomly from UTC. If your tariff offers you a cheaper rate from midnight then the Comms Hub will actually start that half-hour period plus/minus your offset.

The Comms Hub also has at least five channels of Auxiliary Load Control Switches (ALCS) which operate across the Home Area Network. They are meant to trigger the actual times at which demand-loads are switched on/off within the home.

If, for example, you have an EV charger which is being triggered remotely by your Energy Supplier, but using the internet to pass commands (instead of the Smart Meter), then they have no way of knowing whether that charger is being switched on 4mins20secs before or after you are actually being billed at the lower rate!

I find it incredible that Ofgem, as the energy regulator, is allowing such commands to be sent across the internet.

Those 'small' errors in billing are contrary to the licences under which the Energy Suppliers are meant to operate. Moreover, it is now even more difficult to migrate their Billing System Software to offer genuine Time of Use (ToU) tariffs. The accumulated errors would become much more visible to the customers.

I note also your desire to allow alteration of the ASHP flow temperature in response to external tariff data. That's a further step beyond the explanation I've just written... but still feasible if Suppliers and Manufacturers were required to adhere to the original Smart Meter spec. Here's a diagram published by BEIS in 2014 within a public information brochure about the benefits to customers of the forthcoming Smart Meter system:

If we want to discuss the ToU anomalies further then we'll move this into a separate topic.

Wow, I had no idea there was such a big error margin between the "real" time and the time that is used for the ToU tariff (I assumed there was some error <1m but 4m+ is huge). Is there a way of finding out your particular Comms Hub/Smart Meter's offset? I assume this is done so that 10,000,000 EV chargers don't all turn on at the same time? Really fascinating stuff.

Posted by: @scrchngwsl

Wow, I had no idea there was such a big error margin between the "real" time and the time that is used for the ToU tariff (I assumed there was some error <1m but 4m+ is huge). Is there a way of finding out your particular Comms Hub/Smart Meter's offset? I assume this is done so that 10,000,000 EV chargers don't all turn on at the same time? Really fascinating stuff.

You will probably find that many EV owners will merely program their system to start charging using GMT or BST whichever applies at the time, so you could still have 10,000,000 Ev's all start charging at the same time.

@derek-m  

This is the way I have my EV and battery set up to match the Octopus Go window. Neither are ‘clever’ enough to interact with external triggers  

I haven’t noticed any significant cost slippage due to the random time window allocation. I seem to be billed for what I use between 12:30&04:30.

The bill doesn’t have granularity down to one minute intervals but I think I’d see a higher high consumption rolling into the either the 12:00-12:30 or 04:30-05:00 slots if Octopus weren’t accommodating for this some how. Or maybe the up to 4mins of charge in this slot isn’t significant enough to show up. 

This doesn’t deal with the issue of everyone switching on their EV chargers at the same time, just that the price side might be taken care of.   

We don't know what is the range of random offsets applied to Comms Hubs. That information is not in the public domain for security reasons. And if I did find out, then I certainly wouldn't be posting it on an open forum!

In theory the variation could be as large as +/- 15m. I think it's actually a lot less than that. My analysis is based on what I can deduce from current passing through grid transformers. I'm also grateful to Simon1D on the OVO Forum who used his mathematical modelling skills to calculate his own billing errors during Oct/Nov 2020.

The diagrams I create are illustrative. They're intended to allow politicians and their staff to better understand the issues. In reality it's very unlikely that a ToU tariff would offer just a 30-min period of lower-priced electricity and then revert to the previous price. Here's a more typical graph taken from Octopus' Agile tariff over a couple of days in summer 2021, before the energy crisis wiped out the differentials:

@derek-m I agree that most EV owners will set their charge-times according to GMT. But if their settings on an App are interpreted by the relevant Energy Supplier, then the ON-command still gets sent to the charger using the internet.

The 'current strategy' is to randomise those commands being sent to Smart Chargers. But that simply produces another offset on top of that imposed by the Comms Hub. In some cases the billing error is reduced, and in others the accuracy will be worse.

As @scrchngwsl is now observing, more astute end-users are starting to require coupling between smart devices within the home.

This is the moment when our Smart Meters should begin to yield benefits to customers rather than just the Energy Suppliers. But alas, our requirements aren't being taken into account by the Energy Regulator.

The correct way forward is for BEIS (who created the Smart Meter spec) to instruct Ofgem that Comms Hubs must be used for commands, even if data-feedback gets implemented via the internet. The official channel to BEIS is via our MPs, who pass on such documents to the Sec of State. That post is now filled by Rt Hon Grant Shapps MP.

If we don't communicate these concerns to our MPs, then we can't really complain at the absence of an instruction to Ofgem!

Posted by: @hydros

This doesn’t deal with the issue of everyone switching on their EV chargers at the same time, just that the price side might be taken care of.

I spoke to Octopus (at a high level) earlier this year. So I understand their approach to sending commands and billing customers based on data retrieved from Smart Meters.

They're not using the features inbuilt to our Smart Comms Hubs. However I'm not going to state here what I learned of their command strategy or its accuracy. I'm not an Octopus customer, and I'm grateful for the time they bothered to spend discussing the issue with me.

'Taking care of the price side' may sound ok in 2022, but it's not a proper solution. Until we have LCT and smart-export devices based on signals from our Comms Hubs, everything else is being developed with a foundation built on sand.

The Government wants the UK to become the world leader in technology and smart energy. We can't attain that if we disregard the architects' plans from 2013. The National Smart Meter Network is constructed on solid bedrock.

Changing to Smart Energy control using internet connectivity is foolish. A hostile foreign actor doesn't even have to waste time trying to hack protocols. A straight-forward Denial of Service attack on a server will do sufficient damage. 😥 

No I haven't investigated other countries' use of Smart Meters yet @jeff

The hardware we certify for use here in the UK is the same as that used in other countries, although the frequencies employed for the WAN might differ.

It's now 9 years since our GB Smart Meter spec and operational standards were laid down and approved by Parliament. The majority of the documents are in the public domain. I see little to prevent another country using that information to implement the customer-oriented features which we don't (yet) use here.

Hello.

I am Stewart, a Building Surveyor.  I am looking for [impartial / non manufacturer] help on Air Source Heat Pumps, associated control systems and PV systems for both my home and retro fitting in my projects.

Hi @mk1fan  You're very welcome here. You will find discussions on those subjects scattered all over this forum!

I'll assume, unless you say otherwise, that the proposed solar PV systems are to generate a proportion of the electricity required to run the ASHP. If so, then can we add battery storage into your list?

I live in SW Region which has already reached an annual 'nett zero' for the amount of electricity generated from renewable sources and the amount imported into the area from the National Grid. From the viewpoint of energy, it is therefore more important to add storage than it is to continue installing solar panels on roofs.

The reason this isn't happening is because there's no tariff available which reflect that. Until our Domestic Energy Suppliers offer financial incentives for using/storing electricity which is generated locally, we will instead be spending £billions to 'enhance the grid' with ever larger transformers and thousands of miles of copper cable.

And that's going to be the problem with us discussing the technologies which you're interested in.

There are two different sets of answers:- one which is based on joules and another founded on pounds sterling.

GB isn't rich enough to install all the grid-infrastructure which is required to meet the 2050 Nett Zero target if the existing complex energy payments systems remain in place. But HMG and the regulator, Ofgem, haven't yet grasped that. Consequently they continue to approve schemes to 'install more renewables' rather than overhaul the financial rules.

As you're a Building Surveyor, we therefore need to be careful in promoting particular strategies for retro-fitting into existing housing stock. Once Nodal Pricing* comes in, then the technical solutions will change. Inevitably some householders will get their fingers burnt... having just installed products which will then have a longer time to recover the costs.

I'm taking a risk in the opposite direction - installing electricity storage which will not be viable until I can sign up to a tariff based on Nodal pricing. 😲 

Such a strategy involves creating control systems which don't yet exist.

* Nodal pricing is also called Locational pricing. It's the term used by Ofgem and National Grid ESO (Electricity Systems Operator) to describe electricity tariffs based on renewable generation within the local area. Everyone agrees that it needs to happen, but no one wants to upset the major energy companies by changing the financial model on which their profits are based.

I note that my supplier, Octopus Energy, is running trials in a couple of areas local to wind generation equipment (not near me unfortunately) and I feel this is to be encouraged. Meanwhile, my Tesla Powerwall is to be installed tomorrow and I will be watching the daily (or perhaps I mean nightly) cheaper times to charge the battery which will be supplemented by daytime solar energy and assist me in avoiding peak demand times.

Regards, Toodles 

@editor hello and thank you for your kind words, so sorry I am very late replying I couldn't reset my password as the reset email came to my junk folder under Wordpress  so got ignored I was expecting it to come back as Renewable heating Hub and wondered why they never replied to my password reset request. I found it by chance searching for something else!

I have no background in heating, I am however I am an electrician.

Simon