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Discussion Starter #1
Sorry if this has been asked before.

I have a Nissan Leaf. I am thinking of building an off grid solar array and connecting this to a 13 amp socket, via a controller and inverter, to be used to plug in the mains charge cable of the Leaf.

This normally draws 230vac at 10amps from the mains.

My question is: does the output need to be 10amps. If the solar array is only providing 230v ac at 5 amps, would it simply just take that? If the output went up or down, as the sunshine varied, would the car just accept what it was given?

thanks
Alan
 

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I think you can go to 6 amps. But you should also consider lower voltage. The charger should run off 210v easily to cope with the rest of Europe and possibly 120v looking at the markings on the side of the box allowing really low power charging. I'd try plugging in using a builders transformer and see if there is any joy. Should be able to get down to about 1kw if it takes 120v off the brick.
 

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Discussion Starter #3
It is worth considering supplying it with 110vac, thanks. Although if the solar array is only giving out 500W then it would still only be 4 or 5 amps. What I am really after is for the car to take whatever the solar array provides and use it. Whether that would be 500W or 2.5kW.
I suppose that one way around it would be to have a nice big stack of batteries or a Tesla Powerwall (which is the same thing).
 

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Yes, the Leaf will charge at 6 amps. I'm not sure if it would work with less though; the evse might just cut out. An improvement would be having a stack of batteries charging from the solar, so the car could always receive 6a. You are going to need a big solar array and battery pack to manage this in winter though.

Personally, I think you would be better off grid connecting your solar, so that the grid can fill the gap when the solar isn't producing.
 

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otleyshev ( kev)
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There are threads on solar pv charging on here.
The car can be charged at other amps down to 6 amps but it cannot be variable
Need to charge my ev from my solar via immersun
This might be great news if my nissan e-nv200 bespoke campervan can charge 240v ish at 6amp as been told that some of camp sights run lower ampage abroad like say Spain ? France it would be nice to charge van up when I go abroad next year hofully going to France Spain Barcelona etc so think I might have to do a lot of homework cards sites etc etc ??
 

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Discussion Starter #7
Yes, the Leaf will charge at 6 amps. I'm not sure if it would work with less though; the evse might just cut out. An improvement would be having a stack of batteries charging from the solar, so the car could always receive 6a. You are going to need a big solar array and battery pack to manage this in winter though.

Personally, I think you would be better off grid connecting your solar, so that the grid can fill the gap when the solar isn't producing.
I think the way to go is with batteries. Thing is, I think that I would probably need at least 8 x 6v @ 240Ah. That would allow me to put around 6kW in per day without draining the batteries.

I don't really want to connect to the grid. The project I have set myself is to drive my Leaf totally powered from the sun. (apart from 100+ mile journeys)
 

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I'd love to do the same (I even have a sticker on the back of my Leaf saying 'solar powered', as I try to charge whenever the sun is shining), but unless you have a field of panels you need to be realistic. How big a solar array are you planning? My 4kwp (16 panel) dual-tracking east\west array outputs over 20kWh in the height of summer, but produced just 5.2kWh today (which was mostly bright sun). Most days in the cloudy\wet winter you would be lucky to get 1kWh. Also, that amount of batteries won't be cheap, and being lead-acid means they will need replacing every few years.

Better to spend the battery money on even more panels, and accept that you will have to use a bit of grid power during bad weather. It also means you can use the excess power around the rest of your house when the panels are overproducing. If you sign up with a green energy supplier (I am with Ecotricity) you can still say the Leaf is powered by 100% renewables.
 

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Discussion Starter #9
I'd love to do the same (I even have a sticker on the back of my Leaf saying 'solar powered', as I try to charge whenever the sun is shining), but unless you have a field of panels you need to be realistic. How big a solar array are you planning? My 4kwp (16 panel) dual-tracking east\west array outputs over 20kWh in the height of summer, but produced just 5.2kWh today (which was mostly bright sun). Most days in the cloudy\wet winter you would be lucky to get 1kWh. Also, that amount of batteries won't be cheap, and being lead-acid means they will need replacing every few years.

Better to spend the battery money on even more panels, and accept that you will have to use a bit of grid power during bad weather. It also means you can use the excess power around the rest of your house when the panels are overproducing. If you sign up with a green energy supplier (I am with Ecotricity) you can still say the Leaf is powered by 100% renewables.
Great info ref your panels. thanks. 1kWh for a day is really low, especially with tracking. I am going to ground mount the panels which will allow for easy cleaning and a 'once-a-month' manual elevation adjustment. I too am with Ecotricity so I can use some of my 52 complimentary charges during the lean winter months.

I haven't done my maths fully yet but I am thinking of a 3 - 4 kWh system with 10kWh battery bay.

I am pricing up buying in separates and doing it myself, keeping off grid and forgoing the feed in tariffs. Of course I will have the grid as well. I am looking into using Lithium ion batteries, the 3.7 volt ones you get out of laptop batteries. They are maintenance free and don't mind the charge/discharge nature of this. I will need several hundred of them. My rough calculations work out at around £3,000 with battery back up for a 3.5kWh system.
 

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Just to clarify; I meant dual trackers (on the inverter), not tracking. The panels are fixed to my house roof, 8 east facing and 8 west facing. Each roof has its own string connection to the inverter for maximum power.

Checking back over the last week or so there have been 3 days that only output 1.2kWh; the depths of winter will be even worse.

If you aren't interested in the FIT you can use secondhand panels to reduce costs. Take a look at bimble solars website. They specialise in off grid and secondhand panels. I've got one of their 175W panels on my shed roof in a little off grid setup. It charges a car battery, linked to a small inverter that charges my cordless power tools etc.
 

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Discussion Starter #11
Just to clarify; I meant dual trackers (on the inverter), not tracking. The panels are fixed to my house roof, 8 east facing and 8 west facing. Each roof has its own string connection to the inverter for maximum power.

Checking back over the last week or so there have been 3 days that only output 1.2kWh; the depths of winter will be even worse.

If you aren't interested in the FIT you can use secondhand panels to reduce costs. Take a look at bimble solars website. They specialise in off grid and secondhand panels. I've got one of their 175W panels on my shed roof in a little off grid setup. It charges a car battery, linked to a small inverter that charges my cordless power tools etc.
Sorry, I am new to the terminology. Thanks for the tip about Bimble. I notice they have 175W Monocrystalline panels for £65 each. Although they do look like they could be dirty.
 

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Roger Davis,
You do not say where you are but your PV output is not very good. Perhaps you have shading issues?

Most South facing PV systems in England will achieve something close to 1000kwh/kwp ie 4000kwh for a 4kwp system
see for predictive, which has proven to be most reliable PV potential estimation utility start by clicking on the map with your locality. In the height of summer a E/W system can produce more than a South system,but not the best for winter.

Obviously one cannot charge a EV on solar everyday but it can certainly do a very large amount particularly if by charging on a good day it lasts a few days.

This week has been a good one for the PV/EV

If we look at the big picture 4000mls/yr in a EV requires 1000kwh/yr which is easily doable and is less than everybody is exporting to the grid ! BUT if your car is not at home in the day to charge well...

To make this idea work it is necessary to have something like a Immersun that can switch a relay to control charging of the EV

Ken
 

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I'm in SE Scotland and I get around 3500kwh per year from my 4kw unshaded south facing array. In winter I get plenty of days less than 1kwh, and even I have days where my peak output 4A, and even then for short periods at a time.

So battery storage might be the only way to consistently guarantee a decent continuous load is available for charging, and even then there could be many days in winter when there simply is not enough to charge the EV.
 

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Discussion Starter #14
Thanks for that utility link. I live in South Wales. The utility gave me a daily average output of 11.1kWh (333kWh per month/4000kWh per year).
I am retired and so my EV is parked outside during the day quite a lot.
I am planning on doing around 10,000 miles per year. This equates to around 200 - 250kWh per month. So with a decent amount of batteries I should be OK, with a little left over for general house things. And there is also the free charges from Ecotricity, Nissan and places like the National Trust, to supplement that.
 

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I'm in Wiltshire, and have no shading issues at all. Being east\west means that winter performance will be lower than south facing, but will make up for it in the summer.
 

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Sorry if this has been asked before.

I have a Nissan Leaf. I am thinking of building an off grid solar array and connecting this to a 13 amp socket, via a controller and inverter, to be used to plug in the mains charge cable of the Leaf.

This normally draws 230vac at 10amps from the mains.

My question is: does the output need to be 10amps. If the solar array is only providing 230v ac at 5 amps, would it simply just take that? If the output went up or down, as the sunshine varied, would the car just accept what it was given?

thanks
Alan
The way the charging protocols work the charger tells the car how much current is available. The lowest current level that can be signalled is 6A, so there's no way to charge below that level.

In general while I understand the intuitive appeal of an off-grid system it does feel like you're making everything harder, more expensive, and less effective for yourself by doing this. A grid-tied system would be so much easier.

If you're absolutely determined to charge your car from pure off-grid solar, and hang the costs, then the best answer is actually to use CHAdeMO - because in that case it's the charger that decides how much current to send, and so it can go right down to 1A or even a tiny trickle if it wants. You'd need a DC-DC converter to match the pack voltage, and then you're effectively trickle charging the car battery directly.

But realistically that'll cost you >£10k and invalidate your warranty though :eek:
 

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A 4kWp off grid solar setup, with 6kW of batteries, a big charge controller (to charge the off-grid batteries) and 3kW inverter (to convert the battery DC to 240v AC for the EV 'charger' to plug into) plus all the wiring etc is probably going to cost £10k as well. £10k buys a lot of electric from the grid (200,000 kWh at an E7 rate of 5p\kWh). That's nearly a million (ok, 800k) EV miles (at 4 miles\kWh). You can't even offset the costs of the setup with the FIT income.

It's a lovely idea, and I've had similar thoughts, but economically it doesn't make any sense. Sorry.
 

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Discussion Starter #18
Thank you both for your info.

Knowing it will charge at 6A is handy, but I think that it would have to be 10A otherwise it would take too long. I would need to charge at 230vac 10A for 1-2 hours a day, on average.
I wouldn't want to go down the DC CHAdeMO route... too risky.
Using Bimble, I have worked out the 4kWh Lead acid battery system to be half that or £6k with NiFe batteries. But £5k/£6k can still buy a lot of miles.

It is probably not practical but I will keep investigating.
 
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