TonyT Posted January 30, 2022 Share Posted January 30, 2022 So a few new cars allow you to connect load of 3kw plus to the car. so assuming you don’t want to buy a bank of lithium batteries to power your home, how would you integrate this to provide the same function? it’s an adaptor that fits to a charging port so will need a manual plug inserted Link to comment Share on other sites More sharing options...
Dave Jones Posted January 31, 2022 Share Posted January 31, 2022 vehicle to grid needs both your energy supplier and car to be V2G compliant. It looks like a really good way forward to time shift electricity demand to when its cheaper. With 100kwh+ batteries in cars they could run a house for long time if needed. Link to comment Share on other sites More sharing options...
markc Posted January 31, 2022 Share Posted January 31, 2022 Discussing this with someone yesterday, we supply a lot of machines with lithium batteries and our biggest concern is the number of charge cycles. assuming you plug your EV in a home every day and use it everyday then you would get 365 charge cycles per year which isn’t too bad. if you then start discharging and charging several times a day the battery life will decrease rapidly. Link to comment Share on other sites More sharing options...
SteamyTea Posted January 31, 2022 Share Posted January 31, 2022 Just now, markc said: if you then start discharging and charging several times a day the battery life will decrease rapidly. I have been wondering about this, but if they are managed carefully i.e. 15% discharge rather than 80% discharge, and with the latest design chemistries, it should not impact too much, especially if the power draw is small i.e. 6 kW. Some EVs have now done 500,000 miles on original batteries. https://electrek.co/2016/11/01/tesla-battery-degradation/ I still think it is an unnecessary thing to do as the battery pack and management system in a vehicle is heavier and more complicated than what is needed for a home. Not as if we carry a slab of windturbine foundation in the boot of the car to 'show how green' we are. Link to comment Share on other sites More sharing options...
Radian Posted January 31, 2022 Share Posted January 31, 2022 11 hours ago, TonyT said: so assuming you don’t want to buy a bank of lithium batteries to power your home, how would you integrate this to provide the same function? Batteries degrade whatever their chemistry. Get 'em out of cars and hang 'em on the wall when <75%. Way too valuable to waste on the grid. Link to comment Share on other sites More sharing options...
TonyT Posted January 31, 2022 Author Share Posted January 31, 2022 This isn’t grid connected its vehicle to load, differs from vehicle to grid Link to comment Share on other sites More sharing options...
SuperPav Posted January 31, 2022 Share Posted January 31, 2022 Given EV's are my day job, I can comment on some aspects here... 1) The degradation thing, as SteamyTea suggests, is a non issue if you manage it to small amounts of SoC, and within certain windows. E.g. it will only ever charge-discharge by +/- 10-15% and always within a prescribed window (e.g. 40-75% total state of charge). The degradation at these levels is virtually non existent. 2) The biggest difficulty with it all is creating these parameters within which the OEM will allow its car's use as a battery bank, and the integration of that with the grid and different brands' equipment. Relatively simple if all are coming from the same manufacturer, virtually impossible to do it as a universal plug-n-play without a lot of work on protocols and standards. This is why something like a Tesla PW concept is the "best", in that it's an OEM-created storage solution, with all of the sign-off and interfacing with the grid. Adding a (in this example) Tesla charger, and a Tesla EV as an extended buffer is relatively straightforward. 3) Some additional electrical safety regulation work is still required for the V2G side of things to be compliant, but to be fair this part isn't insurmountable. 4) With the price of used battery packs dropping at a rapid rate as EV adoption increases, I suspect it'll be much easier, cheaper, and "greener" to just integrate complete used modules into a permanent home storage installation with swappable module banks. Even a 50% degraded EV battery is still way more capacity than is required for any normal domestic power storage. However, there are some cases where V2G is really suitable and I suspect it will mature/develop further. Japan are a fair few years ahead on this as the Chademo protocol actually incorporates V2G within its standards. 1 Link to comment Share on other sites More sharing options...
markc Posted January 31, 2022 Share Posted January 31, 2022 Yes, trying to get our customers to change their machine usage and charging is like banging your head against a wall. theyhave been used to lead acid deep cycle, so leave on charge when not in use then run till dead before charging again …. Just what you don’t want to do with Lithium batteries Link to comment Share on other sites More sharing options...
ProDave Posted January 31, 2022 Share Posted January 31, 2022 3 hours ago, Dave Jones said: vehicle to grid needs both your energy supplier and car to be V2G compliant. It looks like a really good way forward to time shift electricity demand to when its cheaper. It looks a good idea from the grid point of view but a very very very lousy idea from the car owners point of view. Something I would not allow if I had an EV, why would you want to allow extra charge discharge cycles on your battery? Obviously a question to ask when buying a used EV, has it been used V2G and if so reduce the valuation of the vehicle accordingly. Time shifting and grid storage is something the grid operator and energy providers should be funding, not expecting EV owners to dig them out of the hole they have created. Link to comment Share on other sites More sharing options...
TonyT Posted January 31, 2022 Author Share Posted January 31, 2022 1 hour ago, TonyT said: This isn’t grid connected its vehicle to load, differs from vehicle to grid Link to comment Share on other sites More sharing options...
SuperPav Posted January 31, 2022 Share Posted January 31, 2022 33 minutes ago, ProDave said: It looks a good idea from the grid point of view but a very very very lousy idea from the car owners point of view. Something I would not allow if I had an EV, why would you want to allow extra charge discharge cycles on your battery? Obviously a question to ask when buying a used EV, has it been used V2G and if so reduce the valuation of the vehicle accordingly. Time shifting and grid storage is something the grid operator and energy providers should be funding, not expecting EV owners to dig them out of the hole they have created. Sure, that's a consideration. But what if we you were paid for it? Or at least offset the cost of charging your car? As an OEM, I can guarantee you that there would be no allowance of any V2G without strict parameters on the vehicle side (as mentioned in my previous post), so the battery abuse is a non-topic. An OEM would simply not allow V2G in situations/conditions which would degrade the battery, as it's the OEM ultimately that would be dealing with warranty claims. Any approved V2G interface would be one where the user doesn't need to worry about the degradation. 1 Link to comment Share on other sites More sharing options...
MikeSharp01 Posted January 31, 2022 Share Posted January 31, 2022 1 hour ago, TonyT said: This isn’t grid connected its vehicle to load, differs from vehicle to grid Not sure anybody is listening are they - perhaps see it as V2G = V2L when the load looks / feels like the grid I guess. Just skimming the above tells me, I may have got the wrong end of the stick, that provided your car has V2G capability and you can fool it into thinking it is being asked to feed to the grid it will deliver to your load instead. However it sounds like the 'car system' will limit what it can deliver based upon what the manufacturer is prepared to allow and you will need to be able to provide the protocol standard communications to make it happen. @SuperPav's post above makes it clear I think and identifies the challenges. Link to comment Share on other sites More sharing options...
SuperPav Posted January 31, 2022 Share Posted January 31, 2022 This is why a single-OEM system "V2L" connection is more easily executable. The car only needs to know it is supplying to (or drawing from) e.g a Powerwall of its own manufacturer. The Powerwall can then have the necessary algorithm to work out whether it is dumping direct to loads in the house, topping itself up, or exporting to the grid. This is for the primary benefit of the homeowner. Connecting a car directly to the grid is much harder, and therefore having an intermediate buffer/control like this makes the whole thing easier from an integration point of view. Equally it makes it almost impossible to have a system that is agnostic to the brand/type of car, which is where a universal EV charger with V2G capability (and the necessary interface/approvals directly with the grid) comes into play. Once that protocol and standard is defined, and adopted by the DNO's and OEM's, it will provide direct V2G capability in the same way that Chademo has been rolled out in Japan. This is for the primary benefit of wider "society" i.e. it could be used to load balance an office or apartment block, or a grid. Link to comment Share on other sites More sharing options...
SteamyTea Posted January 31, 2022 Share Posted January 31, 2022 After 3 hours drive today, I am enjoying lunch at a motorway service area. Cost me 2 quid. Bargain. Couple of hours left to do, then a coffee in town at nearly 3 quid. They must be running the coffee machine off a Model X. Link to comment Share on other sites More sharing options...
MikeSharp01 Posted January 31, 2022 Share Posted January 31, 2022 6 minutes ago, SteamyTea said: enjoying lunch at a motorway service area Is that what they call an oxymoron. Link to comment Share on other sites More sharing options...
Dave Jones Posted January 31, 2022 Share Posted January 31, 2022 3 hours ago, Radian said: Batteries degrade whatever their chemistry. Get 'em out of cars and hang 'em on the wall when <75%. Way too valuable to waste on the grid. not necessarily, liquid metal batteries look very promising. Link to comment Share on other sites More sharing options...
Radian Posted January 31, 2022 Share Posted January 31, 2022 20 minutes ago, Dave Jones said: not necessarily, liquid metal batteries look very promising. While they don't suffer from electrode degradation, overall, they're subjected to lots of thermal stresses. I would think that keeping molten metals at 240C wasn't a great prospect for use in transport applications although I do understand advances are currently being made in lowering their operating temperatures. Doubt they'll be any great use for applications other than grid storage though. Link to comment Share on other sites More sharing options...
SteamyTea Posted January 31, 2022 Share Posted January 31, 2022 (edited) 2 hours ago, MikeSharp01 said: Is that what they call an oxymoron. No. Macdonald's cheeseburgers. Only £3/kWh. Bargain in food terms. 2 hours ago, Radian said: I would think that keeping molten metals at 240C wasn't a great prospect for use in transport applications My engine gets pretty hot. Not as hot as my first car, that got so hot it burns the head gasket away. For at least 20 years people that claim to know have told me that Redox batteries are the future. Mate of mine was selling them. Well actually he was not selling them. Had a great calculation to show that they were the cheapest on the market. When he quit (when his own money ran out) he told me that my ballpark figure was much closer to the truth. Think it worked out at 65p/kWh then. Edited January 31, 2022 by SteamyTea Link to comment Share on other sites More sharing options...
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