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Say hello to our new vehicle-to-grid (V2G) charger!


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By pumping EV battery power back to the grid at peak times, our new V2G charger helps reduce over-reliance on fossil fuels.

We think this is a huge leap forward towards a greener future!

Arriving this summer, you can find out more about its game changing features and register your interest here.

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I am a believer in renewable electricity combined with battery storage to make our country energy independent. I can afford to be an early adopter and so have a 4kW solar system that helps to power our house and immersion water heater. We do not need gas water heating from mid-late April to mid-late October depending on the sunshine we get.

I am augmenting this with a Tesla Powerwall 2 battery that will mean I should be able to extend to time my home is electricity self-sufficient. I have now heard that Ovo is going to offer a vehicle to grid charging/reclamation scheme. My 40kWh batteried Nissan Leaf will be able to soak up solar or Economy 7 electricity and discharge to the grid at peak times to earn me a bit of cash, AND, level out demand on the grid meaning that we will not need extra generating capacity to charge my car.

Think about that a moment. A miilion electric cars charging on home grown solar or Economy 7 cheap electricity will mean that we could do away with coal, gas and nuclear generation. That is, if we increase our solar and wind generation enough to be stored in our batteries.
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I detect a sense of excitement, @Absolute Zero!

This is indeed an intriguing announcement today. I've been trying to assess how it is able to provide the V2G functionality, and I've noted two things thus far:

1. This charger is clearly created by OVO in association with Nissan, whereas the other one is generic. So I'm concluding that this charger interacts with the V2G firmware built into the Leaf.

I don't yet know whether that means earlier models of Leaf can be upgraded to support this feature. I would hope so, even if that means a software upgrade by a Nissan Main Dealer.

2. If you read @Darran_OVO's 2nd post on the other charger announced today, he mentions it being synced to your Smart Meter. The main OVO pages also say that it won't be available until the autumn.

This makes sense. We expect the newer SMETS2 firmware to be released around the same. Moreover SMETS2 has a concept of Auxiliary Load Control Switches (ALCS). These allow other Smart devices to be controlled via the meter. If my assumption is correct, then OVO could well have just unveiled the first ALCS device, and that's quite a coup!

As for your Tesla Powerwall, we need to do a bit more investigation. I don't think the current Powerwalls are ALCS-aware, in which case they won't be able to handle power-to-grid in the same way.

The neat bit about OVO offering an ALCS-enabled charger is that the customer can set up preferences (via an App) which allow charge to be resold back to the Grid only within those parameters. So for example, you could give the instruction for OVO to sell back a certain %age of stored electricity, but only once the price reaches 7p per kWh or greater.

There's still a load of conjecture in what I'm posting here. But there might be others reading this who can help clarify matters.
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Transparent wrote:

This is indeed an intriguing announcement today. I've been trying to assess how it is able to provide the V2G functionality, and I've noted two things thus far:

You're far more clued up than I am.

I ordered the Powerwall 7 months ago so there was no hint of V2G coming this soon then. It looks as though the switching & software for disconnecting from the grid will not be available from Tesla until much later this year (KoffKoff).

I read somewhere that the older Nissan Leafs can be connected up for V2G and are doing so in Japan.

I told Ovo that I don't really want a smart meter until they roll out SMETS2.
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I'm only "clued up" because I make technical comments on open forums and then learn from all those who correct me! :P

You know more about the Powerwall than I do. And it's cheaper learning from you than it is to out and buy my own Powerwall!

I'm wondering whether we should use the term V2G for a device that is static (not a vehicle), but I'm not sure of the alternative. A Storage Battery has alternative ways of functioning that aren't present on an EV. After all, you can charge it either buy buying electricity from the Grid when it's cheap, or from a renewable source (SolarPV) when it's generating.

Nor do I know whether V2G in Japan would use the same Smart-Meter with ALCS that we're going to be rolling out in the UK. It could be controlled quite differently.

I wonder if OVO have considered a customer like you who could have both an EV and a Powerwall. If you charge your Powerwall Battery whilst you're out driving the EV, and then plug in the EV when you get home, would it take the (free) electricity from your home-based battery immediately, or sit and wait until OVO's algorithm decides that the Grid price-per-unit is low enough to turn on the Smart Charger?

There's a lot to discuss here isn't there?!
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I think there is a difference between V2G and a static battery like the Powerwall. Don't forget, the Leaf can be charged from Economy 7 as well as my solar or daytime rate electricity.

I can charge the Powerwall using solar or Economy 7 and could flog it to Ovo when they need it at breakfast and tea time. If they had the facility to take it.

The Powerwall is costing me £5,000 plus VAT & fitting. Vat for the battery is 20% but if I have a solar installation too it drops to 5%. Obviously, I am having another couple of 300W panels, inverter etc as well as the battery for the same cost as just having the battery.

I am wondering how "smart" the V2G system is? Will have the same solar facility as the myergi Zappi I've got fitted. At present, the solar is powering this computer, a washing machine as well as pushing a few electrons into the car.
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This is interesting, @Absolute Zero.

I think comparisons are going to be tricky whilst we don't yet know anything substantive about the Tariff structures under which Energy Suppliers (incl OVO) are going to offer for Grid-feed devices.

I think we're going to see a phased migration, starting with the present scenario used for PV Solar (& domestic wind/water turbines), then a phase based on fixed-rate purchases where the device (EV or Powerwall etc) are controlled via the Smart Meter, and finally a phase where we are offered half-hour slots with variable rates.

From what I saw on Twitter of yesterday's Product Launches, the illustrative maths is done on a fixed purchase rate of 7p/kWh. It's quite a low figure, but just enough to run an average Nissan Leaf for nothing if you fit the scenarios used by OVO. So it will probably have a reasonably significant market impact.

The crunch technical question is whether your home-based Li-ion Storage Battery is run by the forthcoming ALCS system. So whether it's a new OVO Home Battery (5kWh or 10kWh) or a Tesla Powerwall, you, the customer, decide when to offer its stored energy back to the Grid.

Until then, it will be up to OVO to set the rules, so they take your stored electricity at breakfast/tea-time etc, according to the National peak-demand curves. That's a primitive, but workable tariff, and a step in the right direction.

These ALCS-controlled devices are extremely smart. They could be trained to track your own set of preferences and "play" these against peak-demands in your local area. If OVO eventually offered that facility, then you could theoretically be able to earn 15p/kWh or so to balance the local grid.

But we're currently right at the start of this new technology being rolled out. That's why neither of us knows whether OVO's Smart Charger will be able to make best use of your free solar-generated feed at this stage. Maybe OVO doesn't know yet either. The Product isn't yet available, and they'll still be deciding what smart algorithms to implement and under what tariff structure.
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Hi,
I am in the process of building our own house and I am trying to make it generate enough to be self sufficient and power our Leaf and Env200. We have installed 3 phase power and I am planning on 12kw of PV.
I was planning on installing 2 Tesla Powerwalls but the cost is about the same as the value of our current 30kw Leaf. I would like to get a new Leaf when they introduce a 60kw version, we find the range of the 30kw is occasionally a headache.
It seems logical to keep the old Leaf for my children if I can combine it with V2G.
Although having 3 EVs in the house seems crazy, it does mean that there would nearly always be one around to leave plugged into the V2G.

I am not really worried about battery degradation of the cars, I assume the same battery pack technology is used for storage as for cars ?
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Hi @timciren,

I'm a self-builder too! I can't find out from your Forum Profile where you are geographically. Does the "ciren" in your UserName derive from Cirencester?

For the sake of others who don't understand, can I just point out that the Env200 is a Nissan small van (EV) similar to the Leaf.

I'm guessing you will defer decisions on the Powerwall until we learn more from OVO about the specs and functionality of their newly announced Home Energy Storage Unit?
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Hi,
Yes we are building in the Cotswolds, have you started work yet ?
I have waited a while for Nissan to actually progress their home storage system, Tesla seems the only option actually available, but I will happily wait a bit longer for details of the OVO, but using what I have instead of buying home storage seems worth finding out about.
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Yes, I'm slowly renovating/extending on old Devon farmhouse. I've doubled the floor area to 300m^2 and added:
  • Off-grid 24v from PV & Wind-turbine
  • Mechanical Ventilation with Heat Recovery
  • UnderFloor Heating from Thermal Store
  • Thermal solar-panel
  • 20m^2 of passive-solar south-facing roof

But taken time out to
a. build an Office-pod for a relative (SIP Construction)
b. part-demolish and rebuild another house damaged by mine-workings

Our next vehicle is probably to be an EV... hence my posting on this thread, and I'm currently working on the "plant-room" where Storage Batteries can be housed.

If you want to discuss more on Self-Building and related Energy matters, say so here and I'll start a new Topic in a place where others would find it.

Returning to this topic, most of what I'd like to do with Grid-connections are best implemented once the new SMETS2 Smart Meters are available. I haven't yet got anything grid-connected until I know more of how this could all fit together.

My area has a glut of renewable-energy generation. I'm part of a Community Group which owns 320kW of PV solar on six local sites. In theory it is technically possible to utilise community owned generation and store it at my own house using EV's or static-storage. But such a tariff can't be offered until SMETS2 and other related technology is available.

There's lots to discuss here over the next few months!

Now get back in the sunshine and continue building! :P
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Hi, I'm new to the forum and follow the subject of sustainable energy with interest.. I am an electrician and use an eNV200 to get around which I love and works really well for me. I've had it nearly 2 years now, it's the 24kWh battery so limited range but is fine for me, around 60 safe miles in the summer.
I'm in the process of having a Powerwall eco 3 home battery installation as part of a trial called Pete. Only 3.5 units of capacity but then my solar is only 2.9kWp.

Transparent, I wd just like to comment on one of your previous posts concerning the maximum household current draw.. its not quite as simple as adding up all the maximum circuit design amps.. it's a lot less than that due to something called Diversity eg a cooker is assumed to draw 30% of its design current, a ring circuit less than that probably. Electric showers and fast chargers, yes they will draw close to what they rated at. Also a 100A fuse won't blow at 100 amps! Sounds strange but it will be more than that and possibly only after several minutes of over current, depending upon how much..
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Sorry that should have said a Powervault eco 3 battery, not Powerwall..
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Good morning @Mikgle... another member from sunny Devon :)

That's sounds a very interesting set-up you have at home. Perhaps you could post more on the Forum area for Home Storage about your reasons for wanting to trial the Powervault and how you are integrating it with your PV array.

I don't want to comment more here because others won't find in within a V2G thread.

Thanks for bringing up the matter of diversity.

I have reached a set of agreements with the Forum Moderators, part of which involves me curbing my enthusiasm for posting stuff that's too deeply technical. As I'd like to expand on the subject of diversity, can I just shout out to @Darran_OVO, that I didn't start this - it's @Mikgle who raised it!

(I try to stick to my arrangements with Darran - especially as I'm currently running in credit to the tune of two pints of real ale!) :P

I'm assuming you've noticed what I wrote about the total household load threatening the 100A Main Fuse on 20apr18 on this thread about the OVO Home Storage unit, because it wasn't here on this page. (I'm adding the link so that others can follow what we're discussing).

Yes I'm au fait with the concept of diversity. Non-sparkys can get a glimpse of this principle by adding up all the values of the fuses/trips in your consumer unit, and noticing that this exceeds 100A... but yet the Main Fuse doesn't blow of course!

I was trying to raise this topic using a "fair comparison" by referring mainly to those electrical devices which provide a long-term constant loading of the circuit. Thus I specifically included an EV fast-charger and electric shower by name, yet only generically mentioned the 30A power ring and the electric cooker circuit.

I probably should've mentioned storage radiators too.

As you're a sparky, I think others would value you mentioning more about what to take note of before considering adding an EV Boost Charger to their home consumer unit.

You are quite right to raise the issue of the time taken for a fuse to blow... which reduces depending on the amount of over-current it is handling.

I have power-monitors on a couple of my devices here which I now know take a lot of power on first being switched on. At the smaller end of the market, I've just built a solid-state PC that runs off 10-30vDC (variable). The internal DC-DC converters take a massive current of more than 10-times the normal running-amps, which surprised me.

At the larger end of the scale I have a 240v AC well-pump, which will reliably blow a 7A fuse at least once a week, and yet is rated 1kW. On further investigation, the switch-on surge is closer to 30A !

It's now on its own 32A rccd :)

Assessing diversity is more than a finger in the air guess isn't it?!
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Hello. I’mjust curious to find out what type of vehicles you dual fuel smart meter engineers are using?
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Hey @Brucey85

Our OVO Engineers are currently using the Nissan ENV200 with the 24kwh battery. This is 100% electric, not a plug-in hybrid.

The exciting news is our fleet is already around 12% full EV at the moment, but we are eagerly awaiting order dates for the same vehicle but with a 40kwh battery which will extend the range of the vehicle by about 50-60 miles and increase the % of fleet vehicles that are full EV to 40% by the end of the year!

Hope that helps!

Darran
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Darran_OVO wrote:

Our OVO Engineers are currently using the Nissan ENV200 with the 24kwh battery.

Will the company be getting any of the new 40kWh ENV200s?

I bought the 40kWh Leaf and I now wish I'd waited for the 60kWh version as the latter will have battery temperature management. The 40kWh car has a "rapidgate" saga ongoing because it does not have battery temperature management. It appears that once the battery gets above 39C, software slows the rate of charge right down. One owner has worked out that not letting the battery get below 20% helps because as the charge gets below that, the battery heats up quite quickly.
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@Absolute Zero

Yes as I mentioned above we are waiting for order dates so we can place an order for the new 40kwh ENV200s!!

Interesting info re the Leaf, wasn't aware of that. Be good to know if anyone else is aware of it and how they are managing it?
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Darran_OVO wrote:

Interesting info re the Leaf, wasn't aware of that. Be good to know if anyone else is aware of it and how they are managing it?

Most people don't drive far enough to charge more than once on a longer journey. It appears that it is after a second rapid charge that the software usually kicks in.

Nissan are aware and state that the slowing charge is to protect the battery. Their data showed that people tended not to do really long journies in the 24kWh and 30kWh Leafs so they weren't bothered about battery management. But, people (me) being people, now want to use that longer range to do much longer journies, more often.

Had I known about this before I bought the car, I would have held off for the 60kWh version.
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That's interesting feedback @Absolute Zero.

There must be some failsafe "temperature management" in the 40kWh Leaf to impose the charge limitation at 39degC. But I'll agree it sounds crude.

If it's in the main vehicle's software, then I'd expect Nissan to issue an upgrade of the firmware through main dealers. But if it's embedded in the controllers sat on each of the 48-stacks which make up the Leaf's floor-pan assembly, then they may not have an upgrade route.

This is an important issue for OVO to consider with the new V2G charger.
Perhaps it needs to detect the model of the Leaf and limit discharge to 20% capacity when feeding the Grid, for example.

@Darran_OVO, I assume the R&D Team are reading this Thread, aren't they?
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Transparent wrote:

If it's in the main vehicle's software, then I'd expect Nissan to issue an upgrade of the firmware through main dealers. But if it's embedded in the controllers sat on each of the 48-stacks which make up the Leaf's floor-pan assembly, then they may not have an upgrade route.

This is an important issue for OVO to consider with the new V2G charger.
Perhaps it needs to detect the model of the Leaf and limit discharge to 20% capacity when feeding the Grid, for example.

I gather that Nissan have told one of the colonies (USA) that the charging restriction is to prevent damage to the battery pack. I can't see any way they can upgrade the car, all they could do is remove the charging limiting software and hope that the batteries will be OK.

I don't think discharging the battery to the grid would be a problem as home chargers don't whack out more than 7kW which is below the restricting charging. I understand the rapids go down to the teens of KW.

And there's more. It looks as though the 40kWh Leaf has another aberration in that it will show the battery empty at about 10%. Allegedly, some sort of algorithm increases the disparity between gauge and the actual amount of charge left. My 2.ZERO is not as efficient as the 30kWh Tekna I had. Tootling around town I could get 5 miles per kWh from the old one and I can't do better than 4 miles per kWh with the new vehicle. I have whinged about this and I am taking the car to the dealer on Friday for them to check it.
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Thanks for clarifications @Absolute Zero,

If temperature is such a problem, perhaps we should have our car batteries charged whilst at Absolute Zero :P

Yes, I understand the basic principles of battery chemistry and why there have to be compensations made for rises in temperature. My own house has devices running from a (lead-acid based) off-grid system for which I've had to calculate how to handle the charge/discharge regimes. What I've learned over the years applies to what we're discussing here.

My batteries can only take so much charge-per-minute. This differs according to their state-of-charge and temperature.

My main way to limit this uses a (bought-in) switching regulator. If my electricity sources (PV panel and wind-turbine) are feeding in too much juice, the regulator slowly increases the amount that it siphons off into a dump-load. This pulse-width modulation is fine for most occasions.

If Nissan used the same approach with the 40kWh Leaf, then their charge-regulator would slowly restrict the current-flow whilst monitoring that the cell-temperature doesn't rise above 39degC.

However, my in-house off-grid battery array sometimes also has to cope with sudden overloads, such as a very strong gust hitting the wind-turbine when the batteries are pretty well fully-charged already. The main dump-load system simply isn't enough.

At those times a further regulator is switched in, offering an additional dump-load to absorb the energy and protect my £1000 battery-array. It's coarse, but effective.

Now if that's what's happening to the Leaf, then I think the design needs re-tuning. I expect there's a temperature sensor embedded into each of the 48 cell-packs. They need this in any case to measure the rate of charge (delta-temp/delta-time if you understand the technique).

If those temperature sensors see a rise above 39degC as requiring emergency action, they may well send a "cut current" notification to the main car's computer, which then drops out of rapid-charge mode.

So instead of the charging regime slowly decreasing the current to keep the batteries below temperature, you get a sudden switch to a standard-rate charge... which is not what you want!

Now there's a lot of conjecture in what I've just described. But it all depends on where in the Leaf the charge-limiting is being done - the main computer, or the embedded units monitoring each cell-stack. If it's the former, then surely a software upgrade could be done.

I wonder how they're intending to change things in the 60kWh variant?
Forced air-cooling to match the rise i temperature perhaps.
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Transparent wrote:

If Nissan used the same approach with the 40kWh Leaf, then their charge-regulator would slowly restrict the current-flow whilst monitoring that the cell-temperature doesn't rise above 39degC.

If those temperature sensors see a rise above 39degC as requiring emergency action, they may well send a "cut current" notification to the main car's computer, which then drops out of rapid-charge mode.

So instead of the charging regime slowly decreasing the current to keep the batteries below temperature, you get a sudden switch to a standard-rate charge... which is not what you want!

Now there's a lot of conjecture in what I've just described. But it all depends on where in the Leaf the charge-limiting is being done - the main computer, or the embedded units monitoring each cell-stack. If it's the former, then surely a software upgrade could be done.

I wonder how they're intending to change things in the 60kWh variant?
Forced air-cooling to match the rise i temperature perhaps.

It appears that 39C starts the slowing process. The higher the temperature, the slower the charging. When done in winter, the drop in charge rate came after two rapid charges. I intend to stop every 100 - 110 miles to keep the battery above 20% and see how I get on. I get bladder anxiety by about 120 - 130 miles anyway.

The 60kWh variant will supposedly have a redesign and actual battery temperature management which I take to mean heating as well as cooling.
Can you just confirm that the V2G as well as providing power to the grid can also be used to power my home from my Nissan Leaf?

Secondly does this V2G also act like the Zappi where by it takes power from my solar panels when there is excess power available?

Thanks Jeremy
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Hey @Capelgors

I've moved your query over to this topic as I think @Transparent and @Absolute Zero will be able to help you!

Cheers,
Emma
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Capelgors wrote:

Can you just confirm that the V2G as well as providing power to the grid can also be used to power my home from my Nissan Leaf?

Secondly does this V2G also act like the Zappi where by it takes power from my solar panels when there is excess power available?

The idea of V2G is that the electricity can go both ways. From grid to EV or house and from EV to house and grid. If I get to be part of the trial, I intend to store solar in the car and Tesla Powerwall 2 and allow the EV to be used by the grid at peak periods.

As to a Zappi-alike, I don't think so, yet? I suspect it will be dumb as far as allocating solar goes and your solar will power your house and EV when there's enough.

Now I've confused myself....

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