Bi-Directional Charging

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SammyD
Posts: 1064
Joined: Sat Oct 13, 2018 7:44 pm
Location: N.E Hampshire, UK

Re: Bi-Directional Charging

Post by SammyD » Thu May 21, 2020 5:33 pm

KEV777 wrote:
Thu May 21, 2020 2:47 pm
Abu Dhabi Dude wrote:
Thu May 21, 2020 1:46 pm
I’m very reluctant to be an early adopter of v2g. It sounds like a wonderful idea, but I am very concerned about the increase in the number of charge cycles the car will go through. I would be worried about the level of degradation this would cause and the reduction in the lifespan of the battery pack. It may prove to be an unfounded fear but I would not like to be an early tester of it for that reason.
Yes agree using up battery life with more cycles will be a concern, but I guess you would only use EV battery to feed house energy requirements at night, not feed stored power back to energy grid. This would mean only a small percentage battery use each night, not a full cycle discharge & recharge. I would also imagine timing and usage parameters/limits could be preset. I can't imagine this type of use would substantially reduce life of battery? I would be happy to use say up to 10 kW from my battery each night if it meant no draw from grid and therefore no electricity charge from energy supplier. I would then recharge car during day once sun shining and utilise home PV or fast charger when out..win win!
This is why you need to understand your home and what each appliance/system uses under normal conditions. Then you will know how much your peak hour demands are on a day by day basis. 10kW is still a lot of energy to use in a day unless you have storage headers.
I have records of my home daily electricity consumption going back almost 9 years. I know what each run of the dishwasher takes, the washing machine, an hour of the top oven at 200C etc etc etc. One thing that people forget is the use of leccy by their gas central heating. It can be more than you think.
But even with 10kWh per day that is not a huge drain on the battery especially as it is spread over several hours. That's why I don't think it will have a great impact on battery life.
Driving "Hirundo Rustica" since 15th Mar 2019. Lovely Jubbly :D :D
S20A_20.07.5-507626 Maps : whatever is current.

fa147
Posts: 899
Joined: Thu Aug 08, 2019 1:25 pm
Location: London / United Kingdom

Re: Bi-Directional Charging

Post by fa147 » Thu May 21, 2020 5:59 pm

KEV777 wrote:
Thu May 21, 2020 2:47 pm
Abu Dhabi Dude wrote:
Thu May 21, 2020 1:46 pm
I’m very reluctant to be an early adopter of v2g. It sounds like a wonderful idea, but I am very concerned about the increase in the number of charge cycles the car will go through. I would be worried about the level of degradation this would cause and the reduction in the lifespan of the battery pack. It may prove to be an unfounded fear but I would not like to be an early tester of it for that reason.
Yes agree using up battery life with more cycles will be a concern, but I guess you would only use EV battery to feed house energy requirements at night, not feed stored power back to energy grid. This would mean only a small percentage battery use each night, not a full cycle discharge & recharge. I would also imagine timing and usage parameters/limits could be preset. I can't imagine this type of use would substantially reduce life of battery? I would be happy to use say up to 10 kW from my battery each night if it meant no draw from grid and therefore no electricity charge from energy supplier. I would then recharge car during day once sun shining and utilise home PV or fast charger when out..win win!
Thinking about this I would think, V2G seems to be to be a buzz word or a fad which won't last long, and this is why; I think.

We are all becoming aware that EV batteries don't just die after their "useful" life has been reached in a vehicle. Those battery would take a very long time to reach the point where they have no value at all, i.e. 10-20% SoH. However, as the SoH of a battery drops, the range of the EV drops and it starts to become uneconomical to own that EV from a time perspective. We currently face the same with mobile phones after we've owned them for 2-3 year as we spend more time charging them than we do actually using them. In the EV world that would be awful.

However, EV batteries that are no longer fit for EV use are then fine to be moved to a residential/commercial batteries storage device because a) there is far more space to store more batteries to meet kW requirement, and b) energy density is not the overriding priority.

So V2G is not going to stay for long because as soon as EV owners realise that they are sacrificing their range to "help the grid", they will stop participating in those programs. Those that think they are saving money by using V2G should also look at the depreciating value of their EV due to lower SoH and see if their depreciation is being offset by their savings, I suspect it may not.

Anyway, why do we have this whole V2G initiative. Well, energy companies know that the "return of electricity to the grid" from residential or commercial properties is an attractive concept. Unfortunately, there is a shortage of batteries which means not many properties currently have battery storage devices, so how can this concept be tested? Well... there are lots of people with access to an EVs, and they could be prime candidates for the ability to test return of electricity to the grid.

However, once batteries start to make their way into battery storage devices (most likely as recycled batteries from EVs) and those becomes cheaper and more prevalent, V2G will disappear for some sort of catchy marketing slogan that describes crowd sourcing of the storage of electricity, i.e. battery storage devices not located at or paid for by the energy companies.

I could be completely wrong about all of this, but that's my view at present. As always, I am happy to be proven wrong.
I-Pace MY20 HSE, Corris Grey, Ebony/Ebony Interior, 20” Grey & Diamond Turned, Panoramic Roof
IMC: S20A_20.16.5-536345 | Telematics: 16.2 | Map 08.030.0106.0154
Home Charging: Zappi 2.0

SammyD
Posts: 1064
Joined: Sat Oct 13, 2018 7:44 pm
Location: N.E Hampshire, UK

Re: Bi-Directional Charging

Post by SammyD » Thu May 21, 2020 6:27 pm

fa147 wrote:
Thu May 21, 2020 5:59 pm

I could be completely wrong about all of this, but that my view at present. As always, I am happy to be shown otherwise.
Much of what you wrote is correct.

I WILL use my EV Battery to run my house
I WILL NOT send power from my EV Battery back to the grid. For one thing, the rates they pay is frankly derisory and just not worth it. The spread between what you pay and what they pay you is just silly. That might change but somehow, I think that the Leccy companies know when that they are onto a good thing so would be reluctant to do it. Then there is the sticky matter of VAT.
Driving "Hirundo Rustica" since 15th Mar 2019. Lovely Jubbly :D :D
S20A_20.07.5-507626 Maps : whatever is current.

sunnyjoe
Posts: 42
Joined: Sat Jan 11, 2020 8:04 pm
Location: United Kingdom

Re: Bi-Directional Charging

Post by sunnyjoe » Fri May 22, 2020 8:53 am

KEV777 wrote:
Thu May 21, 2020 9:54 am
sunnyjoe wrote:
Thu May 21, 2020 9:47 am
This would need hardware changes (suitable internal charger), external compatible charger, battery warranty changes and electricity contract changes.

The only vehicle I am aware of that permits "vehicle to grid charging" in the Nissan Leaf. Octopus is offering a deal incorporating this feature
https://www.octopusev.com/powerloop

As an electrical engineer I think the concept has merit to help the transition to a carbon free economy.
According to articles below Tesla Model 3 is fitted with bi-directional charging capability but was not promoted. Model Y is next to come with capability.
https://www.techtimes.com/articles/2497 ... -homes.htm
https://electrek.co/2020/05/19/tesla-bi ... -features/
The recent stories of Tesla bidirectional charging have been debunked. It is not a Tesla hardware feature
https://youtu.be/ERzUfB-gNCI
Awaiting April 2020 delivery of Caesium blue SE

sunnyjoe
Posts: 42
Joined: Sat Jan 11, 2020 8:04 pm
Location: United Kingdom

Re: Bi-Directional Charging

Post by sunnyjoe » Fri May 22, 2020 9:08 am

A number of people on this thread have suggested that vehicle to grid discharging could be used to run their house and others have expressed concern about the additional battery throughput, degradation and risk of insufficient charge for morning journeys. All of this is highly unlikely because the main application for V2G is likely to be grid support.

In the event of an incident, like a power station unexpectedly disconnecting, grid operators have to find an instant replacement. This is typically spare "spinning reserve" capacity from other already connected generators. That's expensive compared to getting a few Wh (not kWh) from a few million EVs once every few weeks (typically). This is likely the first and main application of V2G. EV owners should get a share of the financial benefit through some collective subscription scheme.

As more and more variable renewable energy (e.g. wind and solar) is connected to the grid it gets harder to match available generation with demand. There are already times when there is too much renewable power (this afternoon my electricity price goes to minus 3.09p/kWh). In a grid dominated by renewables where fossil and nuclear fuelled generators are rarer V2G could help fill the gaps when the wind doesn't blow and the sun isn't shining. That's the application which could potentially need kWh from EVs via V2G and we should be paid handsomely for the value of the energy, reduced range and battery degradation that results. I don't think most countries will be in that position this decade.
Awaiting April 2020 delivery of Caesium blue SE

RodLaird
Posts: 21
Joined: Fri Feb 28, 2020 11:01 pm
Location: Melbourne / Australia

Re: Bi-Directional Charging

Post by RodLaird » Fri May 22, 2020 12:40 pm

Some trials of V2G were done by a mate in Australia but the business went bust; a decade or more too soon. V2G makes sense in Oz. We export about 7MWh/annum and most of the year import none as 20kWh batteries balance load timeshift. (And the energy company pays us...) Cannot be justified on economics- except when you have multiple 42+°C days and grid goes down!! Then the marginal value of power is high!

Have Python script that runs on Synology NAS script controlled by phone linked by MQTT server on same NAS. App GUI auto configures by script on launch. You can set how much you want to drain PV battery and max EV charge and it uses the SolarEdge and JLRPY API modules to manage charging. Setting min PV battery "skims" power that would be otherwise exported for little return. So we have the capacity for about 25,000km/annum at zero incremental cost. No smart EV charger needed; also a saving. Jag Oz provides 5 years of free charging so it could be argued this is pointless; but I don't have to spend time "fetching" it. So pleasing outcome and delivers what I had in mind years ago and is now possible. The coding was fun too :D

Screenshot_20200515-174545_MQTT Dash.jpg

MQTT-dash autoconfigured GUI
cheers from Oz

Rod

White HSE, HUDPANOROOFAIRSUSPENSIONAIRIONISERFOGLIGHTSAMBIENTTOYLIGHTSMUDGUARDSANDOTHERSHIT

Delta5
Posts: 178
Joined: Tue Sep 24, 2019 1:32 pm
Location: Midlands

Re: Bi-Directional Charging

Post by Delta5 » Fri May 22, 2020 1:16 pm

When partly degraded EV batteries become available in quantity Powerwall systems charged by solar or wind will be more common, as has been mentioned selling to the grid is derisory so it needs to be used inhouse. Wether the system is economic depends on grid pricing and the cost and reliability of renewable hardware, the average house that uses £500 of power a year is not likely to spend the current cost of a renewable system
IPace SE Caesium Blue, Ivory interior promised for May or June or July or ———-

ianipace
Posts: 119
Joined: Sat Nov 09, 2019 9:11 pm
Location: Cardiff, UK

Re: Bi-Directional Charging

Post by ianipace » Fri May 22, 2020 5:20 pm

This thread is both fascinating and informative, thanks1
From a bear with a small brain I can't work out how a car would be able to 'top up the grid' and be instantly ready to drive across Britain to see aunty Flo!
I want my I-Pace to be ready to drive from my house here in Cardiff to either of my sons, one in Chichester the other in Sheffield at a moments notice if needs be.
I don't see how that work if I have to stop and charge somewhere along the route! Seems of no benefit at all.

Sadly I have too many Veluxes on my roof to usefully have any solar panels of a sufficient size to be useful as a power source. Given the option to rearrange the roof I'd willingly shuffle things around but that isn't practical or affordable!

Maybe the I-Pace should have been given the option of a solar panel roof? In my case that would only be of benefit when I am in France, as the car goes in the garage here in Cardiff!! Off street is in the garage by the way.
I have seen solar panels that allow light through, so though it wouldn't be as light inside as it is with the panoramic roof it could be a bit brighter inside the vehicle.

Next up, I think only CHAdeMO allows two way flow of electricity, the CCS Combo does not.

There is a thought that the CHAdeMO system will die out for small vehicles, born out of the fact that CCS is the system of choice in both Europe and USA.
China is doing its own thing!
CHAdeMO will be sidelined and used on commercial vehicles, buses, coaches trucks and larger vans. Here solar roof panels are practical and will be of great benefit.
The vehicles in the depot will act mobile charge points and could feed the grid whilst idle.

Battery depletion facts are, by nature of commercial sensitivity, difficult to come by.
The Nissan Leaf was launched in 2011 and suffered with a small battery, and thus range. Interestingly of those original 2011-2 cars, their range has reduced true, but not by as much as pundits believed. On those original cars some are dipping below the 70% but that is after over 8 years of use. Given that battery management has significantly improved, and that the 8 year 70% life has increased, battery usage probably doesn't have much effect on life.
The usual mantra was any rechargeable battery could be charged 1000 times before the chemistry gave out. Battery management has somewhat kicked that notion into the long grass!

I dowloaded the workshop manual from Topix last week and I am pretty sure I could replace a failing cell given the correct tools, and by that I mean a two post lift and industrial marigolds! The battery is laid out in a very easy to get to format when you have dropped the battery! Individual cells can be changed by the way.

I'm still pursuing the CHAdeMO to CCS Combo adapter by the way. An email to Quasar will be winging its way on Monday to see if they could help.

I've been told that JLR Executive are interested in manufacturing one but their pockets are rather depleted at the moment on the cash front to invest in the project!!

Keep safe

Ian
MY2019 SE in Caesium Blue. Panoramic roof and 20" wheels. Ohme Smart charger.

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