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V2G Tariff, Smart Meters, and Solar Panel Export Payments - how does it all link up?

  • 9 January 2019
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OK so I've read the 2017 report. The building transformer was run at 10% rating so will contribute to the poor round trip efficiency. But worse the 2002 design 20kW bi-directional dc-ac converter has low efficiency over the tested operating conditions. I can't think of a good reason why more modern designs would be similarly poor. OVO's unit is 6kW which I would expect is a much better match than a 20kW inverter to the likely export demand.

Perhaps someone at OVO can tell us what the actual efficiency of their V2G inverter is? in the 2017 paper the authors found that the power electronics unit they tested (ac propulsion's AC-150) has losses between 8.28% and 21.80% during dc-ac conversion.
Hi i just move to London and i have a couple of questions.

1) I am really interested in the vehicle to grid (V2G) and i would like to know what is the government regulation about it. I didnt see any news about it in the last months...

2) I would like to know what are the legal documents where the government talk about the self-consume regulation.
How it works for example if i have solar panels? how it works if i use my car´s battery for supply my home?


i would like to read this regulations and legal requirements.

Thank you so much and good work! i like so much your idea! keep on it dudes!
Userlevel 4
I've moved your post over here, @smithsmithers, you'll be able to see how V2G works with solar panels.

In regards to your legal query, I'm not sure about this - hopefully @Hari_OVO can help with this! 🙂
I've moved your post over here, @smithsmithers, you'll be able to see how V2G works with solar panels.

In regards to your legal query, I'm not sure about this - hopefully @Hari_OVO can help with this! :)


im waiting for it 🙂

I've moved your post over here, @smithsmithers, you'll be able to see how V2G works with solar panels.

In regards to your legal query, I'm not sure about this - hopefully @Hari_OVO can help with this! :)
im waiting for it :)

@Hari_OVO can you help me please? 🙂
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Hi @smithsmithers - sorry for the delay in getting back to you...

There's no specific government regulation around V2G, however, the Energy Networks Association (ENA) does provide guidance on exports and the use of micro-generation equipment, like solar and V2G, here.

Thanks,

Hari
Userlevel 7
Badge +2
Can I just add to what @Hari_OVO has said, @smithsmithers ?

Whilst there is no specific regulation about V2G chargers, there are rules about what can be connected to the mains supply of your house.

Any device which is to feed power back onto the supply must be certified to one of

G83 - a generic device which is limited to 16A/phase (about 4kw)

G100 - a generic device which actively constrains a source of microgeneration to no
more than 16A/phase at any given time

G59 - a bespoke installation using items that are not already pre-certified to G83 or G100

These standards now need to have a new one added.

In order to better balance the local distribution network (and hence minimise losses within the sub-station) we require devices which can react quickly to push or pull around 40A/phase on/off the grid.

If you read the spec of the Home Storage Battery which OVO are designing, you will note that it has the potential to operate at 10kW. This could be restricted within its software to feed a maximum 16A onto a domestic single-phase feed, and hence be certified to G83.

However, it would be much more useful if it complied with a new G-standard and was permitted to operate up the full 10kw, depending on the phase-imbalance at the local substation. This obviously requires a monitored sub-station in order to work.

The technology for this exists, but the regulatory framework doesn't.... yet!
Can I just add to what @Hari_OVO has said, @smithsmithers ?

Whilst there is no specific regulation about V2G chargers
, there are rules about what can be connected to the mains supply of your house.

Any device which is to feed power back onto the supply must be certified to one of

G83 - a generic device which is limited to 16A/phase (about 4kw)

G100 - a generic device which actively constrains a source of microgeneration to no
more than 16A/phase at any given time

G59 - a bespoke installation using items that are not already pre-certified to G83 or G100

These standards now need to have a new one added.

In order to better balance the local distribution network (and hence minimise losses within the sub-station) we require devices which can react quickly to push or pull around 40A/phase on/off the grid.

If you read the spec of the Home Storage Battery
which OVO

are designing, you will note that it has the potential to operate at 10kW. This could be restricted within its software to feed a maximum 16A onto a domestic single-phase feed, and hence be certified to G83.

However, it would be much more useful if it complied with a new G-standard and was permitted to operate up the full 10kw, depending on the phase-imbalance at the local substation. This obviously requires a monitored sub-station in order to work.

The technology for this exists, but the regulatory framework doesn't.... yet!


Thank you so much, that is so interesting.

If you dont mind i would like to ask more things because i have no idea about it and i want to install something in my house.

  1. How works the selfconsume in United kingdom? I mean if i install solar panels or i use the battery of my car for supplying my home, I need to pay any backup toll? there are any restriction for the selfconsume?
  2. What happend if i dont have a FIT tariff and i inject energy into the grid?
  3. There are subsidies for providing real time energy adjustments into the grid? i readed that in norway they are going to pay for this service
Thank you so much @Transparent 🙂 and @Hari_OVO
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Badge +2
That's a massive subject @smithsmithers !

And it's one where there will both overlap and differences between my views and @Hari_OVO's.

The whole domestic energy market is changing towards Demand Side Response which will be operated using half-hourly time-of-use (HH TOU) tariffs on SMETS2 Smart Meters.

The way in which we have subsidised the installation of solar panels on houses with single-phase supplies is now working against us. These cause phase-imbalance at the sub-stations which results in energy being lost as heat. Losses have increased from around 5% to 10% in the last 20 years.

Moreover if you were already to have used up all the 16A/phase capacity of the G-standards on solar panels, then you would be forbidden to have any other grid-connected device such as a V2G charger. That's hopeless, because the V2G capability could've been used to flatten out the peak demand in early evening and reduce substation losses!

This is a subject I'm hoping I'll hear more about from @Hari_OVO on the OVO VIP Open-day (17th June) because he's on the guest-list!

I don't know where you live because you haven't yet filled out your Forum Profile, but if there's any way you could be there, then I'd recommend it!

In the meantime, have a look at what I've written here on the Forum about the OpenLV substation monitoring trials.
That's a massive subject @smithsmithers !

And it's one where there will both overlap and differences between my views and @Hari_OVO's.

The whole domestic energy market is changing towards Demand Side Response
which will be operated using half-hourly time-of-use (HH TOU) tariffs

on SMETS2 Smart Meters

.

The way in which we have subsidised the installation of solar panels on houses with single-phase supplies is now working against us. These cause phase-imbalance at the sub-stations which results in energy being lost as heat. Losses have increased from around 5% to 10% in the last 20 years.

Moreover if you were already to have used up all the 16A/phase capacity of the G-standards on solar panels, then you would be forbidden to have any other grid-connected device such as a V2G charger
. That's hopeless, because the V2G

capability could've been used to flatten out the peak demand in early evening and reduce substation losses!

This is a subject I'm hoping I'll hear more about from @Hari_OVO on the OVO VIP Open-day (17th June) because he's on the guest-list!

I don't know where you live because you haven't yet filled out your Forum Profile, but if there's any way you could be there, then I'd recommend it!

In the meantime, have a look at what I've written here on the Forum about the OpenLV
substation monitoring trials.


thank you so much @Transparent
But i still doesnt have clear if I need to pay any backup toll, in other countries this exists.


and you wrote:
The whole domestic energy market is changing towards Demand Side Response which will be operated using half-hourly time-of-use (HH TOU) tariffs on SMETS2 Smart Meters.
But i readed here https://www.smart-energy.com/industry-sectors/electric-vehicles/as-energy-gets-smarter-time-of-use-tariffs-spread-globally/ that there are only a couple of companies with time of use tariffs. What is the most used kind of tarification in united kingdom?

best regards 😁
Hi,

@smithsmithers :
Never heard of a backup toll. Please explain what this is and how it works.

Few ToU tariff in UK other than the long-established Economy-7 (there are variations on this).

Concept: cheaper overnight power (say midnight to 7am), but often with a small hike in the day-rate. For people wit overnight storage heaters, but anyone can ask for it.

Better to charge any EV in day from PV though!

@Transparent don't believe all you read / hear about Smart Meter DSR. These are VERY inadequate. The major problems are with the DNO's, and for them SM's are (today) useless: not enough info, too slow to show fault conditions, behind security walls etc. so not relevant.

EG: local overloads from EV charging need be sensed in minutes and fixed; data via SM's to DSO presently takes weeks. Literally.

Yes, DSR for generation (top-drop view) might be useful but over next 10 years the pinch is at the local level & on the DSO's. And SM's don't work for them; expect another tech solution which is not SG/SM based. See "My Electric Avenue": http://myelectricavenue.info

Those results are for 2014/15 Leaf (3 kW charging) EVs so now out of date. Hence some other solution is needed; what and when is as yet unknown. DSR as-is is not for long....

:)
Steve
Userlevel 7
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@smithsmithers - Octopus Energy have a half-hour TOU Tariff called Agile which has been available for some time. It requires a SMETS1 meter manufactured by Secure (such as OVO used to install prior to 16th March). I assume that Octopus will soon be adding SMETS2 capability although this may need to be on another tariff because the data stream is different.

I have ongoing conversations with my DNO (Western Power Distribution) because I'm in one of the seven Community Teams in the OpenLV substation monitoring pilot scheme. The LV-Cap units in the substations are supplying us with data per minute. For obvious reasons, we mainly work with half-hour data which gives us graphs like this:



I hear what you say @SteveRB, but I would suggest the opposite:

Anyone putting forward a domestic energy strategy which does not comply with Demand Side Response is unlikely to be able to deliver it. DSR was developed by Dept of Energy & Climate Change (DECC) during 2013/14 when Ed Davey MP was Energy Minister. It is already enshrined in the regulatory framework, and Ofgem are supporting its introduction through a number of Network Innovation strategy programmes.

It isn't necessary to use Smart Meters to detect overloads caused by EV charging. This could, of course, be handled entirely via the LV-CAP monitors within sub-stations. EA Technology are already developing a 2nd generation design. It's not that difficult and doesn't require lots of processing power. You could achieve it with an Arduino Mega, as used in most DIY 3D printers.

The trickier part is building the communications network and number-crunching the data once you've got it. I get offered 146 parameters from the one sub-station I'm currently monitoring!

Unlike Smart Meters, there isn't a national security issue because it's only a monitor. No data gets sent in the other direction, so the UK National Grid can't be taken down by a third-party with hostile intent.

But as it happens, in the future there is unlikely to be a major overload problem with increased use of EV Chargers at home. To obtain the best TOU tariffs, most consumers will migrate towards chargers that are controlled using their SMETS2 meters.

These ALCS-enabled EV Chargers rely on commands being sent to the Smart Meters in the first place. So the DNOs can get advanced warning of the likely electricity demand because they simply add up the number of commands per half-hour period being sent to each Electricity Distribution Area.

@smithsmithers - please note that I am discussing a future energy distribution system here. It isn't yet available, but I'm in active communication with many of the people and organisations who are developing it.

There are 80 LV-CAP monitors in substations across the UK (three within 5 miles of me). The reason that Community Groups are involved is twofold -

a. we are investigating what is required in order to allow the wider (non-technical) group of electricity customers to make better choices on their electricity usage. My local group has developed an App which displays current usage data and related statistics. This allows us to survey how they react to having that knowledge.

b. we develop strategies to enable us to build and manage micro-grids, such as that being tested at another OpenLV site, Owen Square in Bristol. The DNOs are required by Ofgem to become Distributed System Operators, which are able to deliver electricity to community-led micro-grid organisations.
:)

@Transparent gosh. Jaw drops open. ...no problems? With EVs replacing cars?

...by my contact at ENA says DNOs are Chinese-walled away from the SMETS data. How then do they have foresight, when the data is encrypted and spread over many retailers, who are supposed to not share it?

Electricity Distribution Area knowledge. How does that help the DNO?

They need to know feeder and phase to control the situation... and SMETS2 meters don't know that stuff; I've looked through the data fields and did not see this (it's easy to have low overall loads but a local overload on 1 phase).

Prey, how does it all work together? Is there a link to a clear plan??

My fear is that this is all "top-drop" views with no visibility of the detail, which says 10 EVs are charging on this phase => fuses go bang in substation.

Thanks,

Steve
PS FYI... OLEV tell me they only give grants for Smart EVSE ... non-Smart are not banned, just not available for a grant. non-Smart EVSE are needed when recharging at a destination with no comms e.g. in deepest countryside. So never-ever-had-a-comms-link chargers will still be about.
Thank you for the answer @SteveRB .

So if you go to your grandmothers house, probably she has a Economy 7? is this the most used in all the houses in UK? the people used to program the wash disher and that kind of things for the valley hours?

The backup toll is in some countries. For example, some years ago, In Spain you had to pay a backup toll. This meant that you paid the DSO for the service of provided you by being connected to the network whether or not you were consuming power. This was bad for people who wanted to selfconsume.
@smithsmithers :
OK. This looks like Distribution network Use of Service charges (DUoS). Those are rolled-up into your retailer bill (at present) - in the UK, you don't have a contract with your DNO, but with the retailer. DNO's cannot charge you (usually).

Thus such a charge does not exist (money is still changing hands somewhere though, like a daily rate of perhaps £0.20 charged to you by your retailer).

Re Economy 7. Well, in the 1960's perhaps, but electric heating has greatly faded out. Only about 1 in 20 still use it; most Grandmothers today would be heated by gas and not on E7!

For EV charging though - might be a good idea; check out what the extra daytime (day rate) £/kWh is; on an E7 tariff this will go up.

Note that electricity is about x4 the cost of gas.... so it is the #1 choice in the UK for home heating, with oil #2.

:)
Steve
Userlevel 7
Badge +2
@SteveRB We really ought to be having this conversation with @Hari_OVO in a Westcountry pub over a pint of real-ale 🍺

... and if you keep throwing in new TLAs without a translation, then we're going to scare off others from joining in here! [ENA, EVSE, OLEV...] 😮

I understand why your "contact" says that Distributed Network Operators are Chinese-walled away from Smart Meters. However, this refers to the first-generation SMETS1 meters, which were deployed by Electricity Suppliers on their own networks.

SMETS2 Meters are installed onto the National Smart Meter Network operated solely by the Data Communications Company, DCC. It is this network which uses the heavyweight encryption.

Energy Suppliers are provided with further encrypted links to DCC over which they can send SMETS Commands and have data returned to them. Of course, these links have sanity-checks and are cross-referenced to ECOES and Xoserve, the keepers of the National Meter Databases for electricity and gas meters respectively. This ensures that only your designated Supplier can send commands to your meter.

Using the same strategy there is no reason why different sets of data cannot be made available to DNOs by DCC.

TOU EV charging does not require Smart Meter data to be exchanged between Electricity Suppliers and DNOs.

Moreover, DNOs must at some stage be required to send the DUoS charge data to the Energy Suppliers once that too becomes variable. Perhaps this should be sent via DCC as well.

My DNO have told me how the DUoS is currently calculated for domestic premises in my area. At the moment it is a static rate, unaffected by the demand peaks of the distribution network which they operate. That makes no sense at all, and has to change.

My area of Britain often has over-supply of renewable energy beyond that which can be fed up the Transmission Grid to the rest of the country. You and everyone else are actually paying compensation to those Westcountry Generators, who Western Power Distribution have to remove from the Grid. 🤑

Using a combination of substations with OpenLV monitoring and aggregated data derived from commands being sent to SMETS2 meters, that excess energy would be better put into EVs (and a number of other storage technologies too of course).

All this is achievable... especially if you factor in the forecasting element that's present in OVO's Vcharge software.

@smithsmithers are you still following this?
Do you want to pull us back to something which you could implement soon rather than looking at future energy strategies?

Now... who's round is it?
Yours, @SteveRB or @Hari_OVO's?
Hi, sorry, i was in a 3 days trip and i disconected my network devices 🙂 freedom jajaja.

@Transparent sorry but about UK i dont have so much knowledge, thats why i came here jeje i am near to move in and i like this kind of things.

I have more knowledge about spain and norway :)


I have one question about the FIT tariff:
does i need 2 meters? i mean, one from my standard tariff (the old one) and the another one for the FIT tariff both of them working in paralel.

So at the end i have two meters, one smart from the FIT tariff that allow me to inject into the grid and the another one my traditional one

is this correct? i readed something about it but im not sure (V2G for my vehicule)
@SteveRB
Hi all,

Yes, there is need for another meter (the FIT meter). The installers of PV systems put one in.

The FIT meter goes electrically between the PV and the incoming power meter; thus, you can use your own power and not be billed. There is also export as against generation; it is possible to add an export meter - but this is unusual. It is assumed by small systems that 50% of the PV power is exported (not used at home).

I've a PV system and that is how my setup is wired.

V2G is helpful, but I for one cannot get sensible economics out of it in mass numbers, although as V2G EVs arrive there are useful things they can do for the DNO. But the DNO has small pockets; I've never heard of them financing V2G (their license terms usually say they cannot inject power i.e. be a generator, although that may change).

:)
Steve
Userlevel 7
Badge +2
Hi @smithsmithers You need to follow what @SteveRB writes on this matter. He actually has grid-connected solar panels, whereas mine are supplying an off-grid Home Storage Battery.

Note also that the SMETS2 Smart Meters which a now being installed have the ability to directly measure exported electricity and record it separately. Moreover they have a number of different Time Of Use (TOU) tariff bands inbuilt rather than just the present strategy of a single Economy-7 rate between midnight and 7am.

If you want to find out more about these subjects, you really need to join in with a local Community Energy Group. These exist all over the UK and are involved with projects like:
  • helping householders to install solar panels
  • disseminating energy awareness in the local population
  • advising the local councils on energy policy
  • energy surveys for houses that have large bills
  • installing community-run energy schemes
My local group is part of the Transition Towns movement and also covers matters such as
  • combating single-use plastics
  • recycling schemes
  • cycle routes for commuters
  • community-run vegetable planters within the town
  • tree planting and ecological diversification programmes
I don't know where you live at the moment because you haven't yet filled out your Forum Profile. So I can't say if I know of a local Energy Group near you.

... and when you reply on this Forum, you don't need to copy the entirety of a previous message, you can just tag someone so they know you have replied to their comment by using @smithsmithers for example. Other people reading the Topic can always see what's been said before! Thanks.

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