bobberjob Posted November 25 Share Posted November 25 Hi all just read some comments on using an ev as battery storage. does this work the same as a regular battery? can you still use the car? we are out in the countryside so no mains gas. We have a stove boiler and Torrent heat store. Anyone doing this at the moment? apologies if this has been covered but I can’t find a relevant thread cheers Link to comment Share on other sites More sharing options...
bobberjob Posted November 25 Author Share Posted November 25 Just come across a topic on the next page. Doh. In my defence I’m pretty old I’d still like to hear from any doing it though Link to comment Share on other sites More sharing options...
Dillsue Posted November 26 Share Posted November 26 Outside of official trials, AFAIK there's nothing certified in the UK yet for a grid tied system. If the car has V2L for power tools/camping etc then it's been suggested that you could hook up the V2L to a grid tied inverter that has a generator input. The V2L from the car is then seen as a generator. You'd need a separate charger to charge the car. Link to comment Share on other sites More sharing options...
markharro Posted November 26 Share Posted November 26 Old Nissan leafs can do this cant they? Is the issue not that there are no two way EV chargers for sale? At least not yet. Myenergi's blog indicates they are developing one to release next year! Link to comment Share on other sites More sharing options...
Dillsue Posted November 26 Share Posted November 26 I think there's plenty of cars including the Leaf that support V2G but there's no bidirectional chargers yet approved for UK use 1 Link to comment Share on other sites More sharing options...
markharro Posted November 27 Share Posted November 27 That's why Myenergi's post that they hope to bring such a charger out for sale next year is particularly interesting I think @Dillsue - https://www.myenergi.com/news/power-to-the-people-myenergi-starts-work-on-new-v2g-ev-charger/ Correct me if I am wrong but one of these + a £2000 old Nissan Leaf on your drive and you have a very high capacity/low budget home battery!? 1 Link to comment Share on other sites More sharing options...
RobLe Posted November 27 Share Posted November 27 We were on a v2g trial for 2 years with a Nissan leaf. We kept it another year after that, then gave it away (post install it has very low value as the company refuses to allow extra units to be connected to their servers). It worked great for us - largely because it was thru lockdown, so the car was just sat there! Things to consider before doing this: It uses up some of your grid tie ‘allowance’, making adding PV more difficult (this is why we stopped). You’ve got a car on yr drive/somewhere all the time. If you have such a spare drive space, you could rent it out on ‘park on my drive’ or some such. The tech is so rare it’s expansive - for the suggested cost of new inverter+install you can get a hybrid inv+15kWh batt It’s all still trial stuff - nothing actually for sale yet. And it won’t work without internet connectivity. In my experience it was more prone to faults than regular non-internet connected inverters. You don’t get the full use out of the car batt - our 30kWh Nissan leaf+v2g had the same useable capacity as our much smaller 15kWh lifepo4 battery - the chademo protocol doesn’t allow the bottom 30% to be used, and an old 30kWh leaf won’t actually be 30kWh anyway. I think there’s a very niche place for v2g ev campervans one day. Maybe tesla will add a connection between car and their power wall. Link to comment Share on other sites More sharing options...
markharro Posted November 27 Share Posted November 27 Thats interesting @RobLe we have 6kw PV at the moment with the potential to go to 11kw are we have a 3phase supply. Can you explain how adding eg a Leaf would affect this? The thing is, Myenergi are indicating that their V2G charger will be affordable. Link to comment Share on other sites More sharing options...
SteamyTea Posted November 27 Share Posted November 27 6 minutes ago, markharro said: we have 6kw PV at the moment with the potential to go to 11kw are we have a 3phase supply. Can you explain how adding eg a Leaf would affect this? I would assume, which is a dangerous thing, that the combined input for each phase, would be the upper limit. So if you are allowed 6 kW/phase, and the V2G is say 2 kW, then your PV can be no more than 4 kW. (It is actually amps they look at, but using rounded up kW makes it easier to visualise) Are these V2G controllers 3P? Link to comment Share on other sites More sharing options...
markharro Posted November 27 Share Posted November 27 I cant say I understand this. We have a 3phase supply so can instal PV up to 11.04kW (or something like that) on our existing G98 permission. At the moment we have about 6kW installed. If we installed a standard home battery does that mean it reduces what further PV we could instal because that would be news to me? Why would or is the position different using a car battery as the "home" battery? Link to comment Share on other sites More sharing options...
SteamyTea Posted November 27 Share Posted November 27 21 minutes ago, markharro said: If we installed a standard home battery does that mean it reduces what further PV we could instal because that would be news to me? Generally no. There may be a limit to how much you can export from your battery, but you would not be exporting (usually). This is where V2G and home battery storage differ. The G is for grid. Would be V2H, which I think exists otherwise. Link to comment Share on other sites More sharing options...
RobLe Posted November 27 Share Posted November 27 A V2G car charger can import or crucially export, so "uses up" some of your export allowance. A hybrid inverter does the same; but usually you can and do add PV to the hybrid inverter rather getting another inverter, so this doesn't take up extra export allowance. Ours could be software limited (not by me) for G99 purposes; the software at the time was such though that this limited import and export identically, so this wouldn't work. As far as I know they have never been actually installed as V2H only - ie. with "never export" hard coded in - obviously it could be, it's "only software" 🙂 Maybe you could get an install with a G100 restriction and an extra PV inverter, again only software 🙂. I've not come across a 3phase V2G unit; single phase ones are rare enough already - I can't imagine demand for a 3phase unit being that strong, so it would cost more. The electronics inside a V2G box are similar to inside a hybrid inverter, but low volume production makes the reported 1P V2G product price around £3000, versus actual 1P hybrid price of around £700. Price is an ethereal concept for objects that have never actually been sold - I think V2G has always been in trial, never sold without strings attached. There's nothing wrong with the concept of V2G; the devils in the detail for consumers though. Having gone through it, I think a hybrid inverter + home batt is a better thing to actually spend real money on right now, as they just work. If V2G achieves mass adoption things will change; it's not obvious to me this will happen before battery prices drop such that nobody cares. Indra made a great summary of their V2G trial, here: https://www.cenex.co.uk/app/uploads/2021/05/Sciurus-Trial-Insights.pdf Link to comment Share on other sites More sharing options...
Dillsue Posted November 27 Share Posted November 27 9 hours ago, markharro said: I cant say I understand this. We have a 3phase supply so can instal PV up to 11.04kW (or something like that) on our existing G98 permission. At the moment we have about 6kW installed. If we installed a standard home battery does that mean it reduces what further PV we could instal because that would be news to me? Why would or is the position different using a car battery as the "home" battery? Under G98 you're limited to 16amp per phase. You need to add up the potential export for each phase, its the potential that your DNO is interested in, not what you might actually do. If you add a battery(car or standalone) with its own AC connected inverter then you need to add the potential output from the battery inverter to the potential output from your PV. If the sum comes to more than 16 amp on any phase then you've gone over the G98 limit and need to get permission for the excess over 16amp via a G99 application. If your PV or battery inverter supports export limitation then you can get either or both set to keep your export to no more than 16amp but you still need permission via G99/G100 2 Link to comment Share on other sites More sharing options...
ringi Posted November 29 Share Posted November 29 It seems to be going towards AC export from the car over CCS rather then DV export over CCS, so once standardised, if mass market should be a relatively little addational cost over a standard new "charger". But would exclude most 2nd hand EVs for a few years. So if I assume that in 6 years time I will have V2H, how does it change the economics of getting a home battery today? Without a heatpump, or with an automatic setback when car is out, for us, V2H would remove something like 95% of our daytime electricity usage. Any EV we bought would have enough range for preplanned trips, but our unplanned range requirements are a lot less. Link to comment Share on other sites More sharing options...
SteamyTea Posted November 29 Share Posted November 29 2 hours ago, ringi said: how does it change the economics of getting a home battery today it doesn't, the home battery will still not have saved any money. Link to comment Share on other sites More sharing options...
ringi Posted November 29 Share Posted November 29 (edited) 3 hours ago, SteamyTea said: it doesn't, the home battery will still not have saved any money. The point is the home battery only have until a V2H setup is installed to recover costs, regardless of how cheap it is to add a battery to a PV inverter. Edited November 29 by ringi Link to comment Share on other sites More sharing options...
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