V2H - EV as home battery?

johnkehoe

Has anyone out there attempted this yet - used their EV as a home battery? As the winter lifts, my 5.3kWp PV array is moving into real surplus for good parts of the day. I can capture some of the excess thru a diverter to the hot water cylinder and a Zappee charger. Battery storage is the obvious next step. Quoted 9.5k for a 12.5kWh BYD battery. Love to try to use the 33kWh battery in my i3 instead!

Shefwedfan

Offer in UK with Nissan 2 to buy with PV Panel and use car as battery....might be worth checking what offer is available from them and copy it.

9.5k for battery backup ouch ! You’d never fill it in winter would you and probably not enough for Summer ?

Grid is the best, if only .......

Gumbo

Deleted User wrote: »

9.5k for battery backup ouch ! You’d never fill it in winter would you and probably not enough for Summer ?

Grid is the best, if only .......

That price is too expensive alright.
I’m winter you’d get something, I was generating hot water during the winter months. Not everyday mind you.

In summer you would more than fill it, ive generated over 10kwh every day this week, including today which was very cloudy, generated 9kwh.

unkel

johnkehoe wrote: »

Quoted 9.5k for a 12.5kWh BYD battery

That's mad. I'd buy a clapped out / crashed Nissan Leaf for less than half that with double the battery capacity

ELM327

unkel wrote: »

That's mad. I'd buy a clapped out / crashed Nissan Leaf for less than half that with double the battery capacity

Or a fluence

kceire wrote: »

That price is too expensive alright.
I’m winter you’d get something, I was generating hot water during the winter months. Not everyday mind you.

In summer you would more than fill it, ive generated over 10kwh every day this week, including today which was very cloudy, generated 9kwh.

10kWh every day this week?? That's quite high especially for this time of year. What is your setup?

Gumbo

ELM327 wrote: »

Or a fluence

10kWh every day this week?? That's quite high especially for this time of year. What is your setup?

3kw system. Completely south facing.

unkel

ELM327 wrote: »

Or a fluence

That would look much nicer on my driveway alright

No CHAdeMO though in the Fluence, so no easy V2H

ELM327 wrote: »

10kWh every day this week?? That's quite high especially for this time of year.

It is high, but it has been quite sunny, with a powerful spring sun. Got a bit tanned myself on a hike on Sunday and I've seen my own tiny west facing 750W setup produce over 500W at times when the sun is out, so a 100% south facing 3kW setup might have easily peaked at over 2.5kW

Gumbo

unkel wrote: »

so a 100% south facing 3kW setup might have easily peaked at over 2.5kW

Peaked at
3.1kw on Sunday
1.8kw on Monday
3.4kw on Tuesday (around Mid Day)

12kwh generated today with a peak at just under 2kw.

catharsis

johnkehoe wrote: »

Has anyone out there attempted this yet - used their EV as a home battery? As the winter lifts, my 5.3kWp PV array is moving into real surplus for good parts of the day. I can capture some of the excess thru a diverter to the hot water cylinder and a Zappee charger. Battery storage is the obvious next step. Love to try to use the 33kWh battery in my i3 instead!

2 Questions
1. What is a Zappee Charger?

2. is there any way to 'divert' to a car in the first place - it seems to me that the car might want to have high-performance steady (i.e. from the grid) power as a prerequisite to stating charging, and how do we start and stop the solar charging of a car if the car is in control of the schedule of charging?

unkel wrote: »

No CHAdeMO though in the Fluence, so no easy V2H

Does this imply that what is being discussed is relatively straightforward if one does have CHAdeMO? -I'd be very interested in knowing more - we have both a 40KWh leaf and a 330e (7KWh) in the family and one or the other will always be in the drive and connected I suspect.

We haven't ordered any of the new charging infrastructure to support 6KW charging of the new LEAF, nor connecting both cars at the same time, and we also have not (yet) purchased any solar array, but all of these purchases will be made over next few months and I'd really like to get all the right pieces in place so that they will all work together as well as possible.

If I could even just do V2H with the Nissan and just use off-peak electricity during the evenings when we are at home and using the kettle etc even that would be a nice to have extra benefit of the whole solution.

Battery storage only works in Countries closer the equator that are a lot sunnier because you won't have such variations in generated power by cloud cover but also by the large difference in Summer V winter daylight hours you can then size the battery much easier. In Ireland you have to dump significant energy, a complete waste.

If battery energy was cheap enough then I'd use it to fill on night rate. But at 7 Cent per Kwh, no chance, doesn't even make solar PV worth while. I can fill the 33 kwh i3 (29.5 Kwh usable) for what, 2 Euro's , big deal. I get a lot of electricity from work too.

KCross

catharsis wrote: »

1. What is a Zappee Charger?

I'm assuming it was mis-typed and it is this guy:
http://myenergi.uk/product/zappi/

catharsis wrote: »

2. is there any way to 'divert' to a car in the first place - it seems to me that the car might want to have high-performance steady (i.e. from the grid) power as a prerequisite to stating charging, and how do we start and stop the solar charging of a car if the car is in control of the schedule of charging?
.

The Zappi does it. It has various settings to maximise the energy generated via Solar with backup from the grid to stop it continuously turning on/off the charge.

You would have to adjust the car charging schedule accordingly of course and have it plugged in during sunshine hours.

catharsis wrote: »

...we have both a 40KWh leaf and a 330e (7KWh) in the family and one or the other will always be in the drive and connected I suspect.

Have you actually received your 40kWh? You must be one of the first in this country if you have.

catharsis wrote: »

If I could even just do V2H with the Nissan and just use off-peak electricity during the evenings when we are at home and using the kettle etc even that would be a nice to have extra benefit of the whole solution.

Dont Nissan have a product specific for V2H. Not sure if its available in Ireland though. I haven't heard of anyone with a commercial product doing V2H on this forum.... other than a few cases of people feeding some low voltage items off the 12V battery which is then topped up by the high voltage battery.... its more of a hack than a V2H solution though.

catharsis

Deleted User wrote: »

Battery storage only works in Countries closer the equator that are a lot sunnier because you won't have such variations in generated power by cloud cover but also by the large difference in Summer V winter daylight hours you can then size the battery much easier. In Ireland you have to dump significant energy, a complete waste.

If battery energy was cheap enough then I'd use it to fill on night rate. But at 7 Cent per Kwh, no chance, doesn't even make solar PV worth while. I can fill the 33 kwh i3 (29.5 Kwh usable) for what, 2 Euro's , big deal. I get a lot of electricity from work too.

I'm confused.

Is the first part of your response talking about battery storage or about solar PV?

Surely the point of battery storage is to prevent dumping energy? (or at least reduce the incidence of having to do so?)

Then you talk about batter energy - I'm lost again, surely energy does not come from batteries but rather goes into batteries? did you mean the capital cost of acquiring them or something?

I am in a peculiar situation in that in my example the capital cost of acquiring a battery is zero - I already have 2.

The marginal cost of a Solar PV system will also be zero (as it will be required for other reasons)

any cost will be in selecting the optimal 'gubbins' (technical term) to glue them together in the most efficient manner possible.

What I am interested in is whether there is an efficient way to connect these systems together so as to use the EVs and V2H instead of 'dumping' energy' - albeit I understand the normal practice is to 'sink' that energy into domestic hot water which means it is not so much wasted as unoptimised?

This would allow me potentially to shift solar energy collected during the day, as well as cheap night rate energy loaded into the car overnight, to reduce the peak load in the house during evening hours.

catharsis

KCross wrote: »

I'm assuming it was mis-typed and it is this guy:
http://myenergi.uk/product/zappi/


The Zappi does it. It has various settings to maximise the energy generated via Solar with backup from the grid to stop it continuously turning on/off the charge.

You would have to adjust the car charging schedule accordingly of course and have it plugged in during sunshine hours.

Excellent - just the type of thing I was looking for albeit I now have to see about one that will support 2 cars (or could I just add this to the house system beside an existing ESB supplied charger?)

KCross wrote: »

Have you actually received your 40kWh? You must be one of the first in this country if you have.

LOL - of course not - only ordered as yet, and even that experience has been full of 'interesting experiences' - Nissan and I were in discussions off and on for 5 months before they mentioned that they could take an order even though they hadn't announced the pricing yet!! I'm supposed to get it in May though.... we'll see if that comes true (and if I bother or wait for the 182 plate)

KCross wrote: »

Dont Nissan have a product specific for V2H. Not sure if its available in Ireland though. I haven't heard of anyone with a commercial product doing V2H on this forum.... other than a few cases of people feeding some low voltage items off the 12V battery which is then topped up by the high voltage battery.... its more of a hack than a V2H solution though.

I have seen references to things like that (mostly in a japanese context) but certainly not aware of it being something I can just walk up and buy off the shelf from Nissan Ireland.

catharsis

In case anyone finds it useful - this isn't really what I had in mind but....

http://www.setec-power.com/supply/vehicle-to-home

unkel

About $2800, so well over €3k incl VAT and import duties

Nice to have, and it does save you money, but that price is a bit much.

KCross

catharsis wrote: »

Excellent - just the type of thing I was looking for albeit I now have to see about one that will support 2 cars (or could I just add this to the house system beside an existing ESB supplied charger?)

You buy two Zappi's and connect them together. They will divert excess Solar to the car(s), use the grid where required and also load balance to ensure you don't blow the fuse. All configurable.

You don't get a free charge point from ESB anymore. You get a €600 grant from the SEAI and you buy whatever you want and get a RECI certified spark to put it in. Look at seai.ie for details on electric vehicle grants and its all laid out there.

catharsis

I already have the free ESB charge point :-)

I presume I am not eligible for another EUR600 in grants which would go some way towards paying for a Zappi?

KCross

catharsis wrote: »

I already have the free ESB charge point :-)

I presume I am not eligible for another EUR600 in grants which would go some way towards paying for a Zappi?

If the first one was registered at the same address they won't give you the new grant.

catharsis

catharsis wrote: »

I'm confused.

Is the first part of your response talking about battery storage or about solar PV?

Surely the point of battery storage is to prevent dumping energy? (or at least reduce the incidence of having to do so?)

Then you talk about batter energy - I'm lost again, surely energy does not come from batteries but rather goes into batteries? did you mean the capital cost of acquiring them or something?

I am in a peculiar situation in that in my example the capital cost of acquiring a battery is zero - I already have 2.

The marginal cost of a Solar PV system will also be zero (as it will be required for other reasons)

any cost will be in selecting the optimal 'gubbins' (technical term) to glue them together in the most efficient manner possible.

What I am interested in is whether there is an efficient way to connect these systems together so as to use the EVs and V2H instead of 'dumping' energy' - albeit I understand the normal practice is to 'sink' that energy into domestic hot water which means it is not so much wasted as unoptimised?

This would allow me potentially to shift solar energy collected during the day, as well as cheap night rate energy loaded into the car overnight, to reduce the peak load in the house during evening hours.

Both, solar PV and Battery storage is uneconomical, V the current cost of electricity.

Too much energy in the brighter months and not enough in Summer means energy still has to be dumped.

If we had grid storage then I'd say happy days but we don't and are unlikely to for many years, the Grid can't take more than the 65% (wind energy) it can currently take at this time and more and more commercial wind farms will take preference and not micro generation.

Anyway, I'd like to hear me proved wrong because it's something that interests me a lot.

KCross

Deleted User wrote: »

If we had grid storage then I'd say happy days but we don't and are unlikely to for many years, the Grid can't take more than the 65% (wind energy) it can currently take at this time and more and more commercial wind farms will take preference and not micro generation.

FYI
It allows up to 75% now and has done so for the last 3 months.
https://www.boards.ie/vbulletin/showpost.php?p=106161788&postcount=139

catharsis

KCross wrote: »

If the first one was registered at the same address they won't give you the new grant.

I don't know if you intended it that way but that was an interesting (and potentially valuable) choice of words.

The leaf's actually going to be my wifes' car and I suppose I could potentially ask her what address she'd like it registered at .....

unkel

Nah, no tricks will work here. They ask for your MPRN number (which uniquely identifies your house)

I like my subsidies, so my plan was to import a cheap Leaf from the UK, get a second free EVSE installed at my home and then flog the Leaf on. But alas, no workies.

catharsis

was thinking more like getting a charger installed at her parents place or potentially at a house she has rented out, which has a garage and could potentially benefit from a free charger....

johnkehoe

Thanks everyone.

So, no-one on here knows of a way to use the i3's battery for V2H (but it may be poss with some Nissan/Chademo batteries).

With my 5.3kWp array, I exported 60kWh last month (according to my Smappee energy monitor, which I find great). So that if the purpose of a battery is to capture exported daytime watts, the battery would save me about EUR9 per month and my EUR9.5k investment into a 12.5kWh battery would take just under 100 years to recoup...(assuming a EUR0.15kWh electricity-day rate and that last month's export is at the annual average).

...though the return looks much better if the or an additional purpose of the battery is to arbitrage the day/night electricity rates: I imported 540kWh last month (so that a 12.5kWh battery would seem not far from correctly sized), mainly, say 70%, by day, so that my saving from this use-case would be about EUR38/month and I'd recoup the cost of the battery after...just over 20 years (assuming an electricity-night rate of EUR0.05/kWh and ignoring the additional benefit of the saved day-export - also assuming the battery's firmware allows it to be preset to charge/discharge by night/day...).

So in my case the day/night arbitrage would be a far more important reason for buying the battery than saving exported day-watts.

My return would be above 5% - fine if battery degradation is ignored (??) and better than what I get on the array itself....(although: everyone seems to expect battery costs to continue to fall fast).

Anyone out there have a battery that's preset in this way to charge only at night-rate?

unkel

johnkehoe wrote: »

So, no-one on here knows of a way to use the i3's battery for V2H

Eh yeah we do. Just hook up a pure sinewave inverter to your aux 12V battery in your i3 and hook your house up to that

(I have a basic 300W inverter ready just for that in case of emergency electricity loss I can still watch telly, charge devices, have lights on, have internet)

We don't know of a more sofisticated way like with the above mentioned V2H devices. It has nothing to do with having a Nissan battery though, it has everything to do with the CHAdeMO protocol / handshake / two-way traffic between car and EVSE