Solar Powered EV charging

[revor]

As soon as we get small BEV's on the market with a bit more range we intend to get one. We have a 6Kw array and 10Kw battery. I wondered if having this set up would influence the type/make of the 7Kw charger we should specify. I would be keen to be able to charge the EV from the excess solar that would be going to export. As this would vary with what the sun is producing and with what we are consuming is it possible to charge a vehicle in this way without making up from the grid. In other words can an EV be charged with a variable input into the charger. It would also be useful to be able at some point to use the EV battery as backup to the solar battery although I think at moment this is limited to certain vehicles

In one my agricultural outbuildings ( I live on a smallholding) I have 3 P on a business tariff and is separate from the PV and house, so wondered if a back up fast charger is something I should consider. From what I can work out I could have a 50KW charger but expect they are pretty expensive. My 3P distribution board needs upgrading so something I could combine with a charger.

 

[Andy™]

car chargers tell the car what power is available, i.e 3kw, 7kw etc, so the car will only take that amount. it may be possible to come up with a device thats variable on this but no idea how well it would work

 

[binky]

There are chargers designed to work with solar inverters. Can't think of any particular make apart from Solaredge. Might be worth contacting a few solar wholesalers for advice.

 

[revor]

Thanks for both replies. Will contact the Inverter manufacturer to see what they say as also need to contact them for some info on how I could couple up a wind turbine.

 

[NozSpark]

TBH there's only 1 EV charge point that integrates well with load limiting, solar and battery... and that is the MyEnergi Zappi 2
What they do is monitor the current that coming from the grid, solar and battery... and then, dependant on the charge setting, send the appropriate charge to the car.... so if your solar is working particularly well one day and outputting 6kW, your house is using 0.5kW, then it can limit the charge to the car to 5.5kW

Chargers are classified - (roughly)
slow <6kW (AC chargers)
fast >6kW and < 25kW (AC chargers)
rapid >25kW (DC chargers)

Normally you can have a 7kW charge point at home on a single phase supply,,, but if you have a three phase supply you can have a 22kW
However,,, there aren't many cars that can make the most of a 22kW charge point, most cars only have a single phase charger on board, some you can spec a 11kW charger,,, and a very few have a 16kW and even fewer have 22kW

If you're thinking of having a 50kW rapid charger installed then I'm afraid that you'll need very deep pockets, you could easily be looking at £15 - £20k, especially if the local grid needs reinforcement

 

[NozSpark]

I see that you're in N Wales.. if you're close enough to Prestatyn give me a shout

 

[Richard-the-Ninth]

I could couple up a wind turbine.

May I suggest before you do that, you invest in an anemometer to see what the wind speed is.

 

[revor]

Many thanks for replies a DC charger is definitely out. I had heard of the Zappi on Fully Charge I think it was, will look deeper into that. Where I am close to coast and at the highest point in my locality albeit 15M above sea level there seems to be enough wind according to my hand held anemometer. My main issue could be planning as though I am not in a AONB the boundary runs down the edge of the boundary to my property. At moment I am getting negative responses in that it is difficult to couple a wind turbine to a system with Li batteries but dead easy with LA due to the BMS but exactly what the barrier is I have not understood yet.

 

[michael8554]

In other words can an EV be charged with a variable input into the charger

Yes.

1. An EV will only charge at the maximum rate the car's charger will accept.
So my 16A max PHEV will happily charge from my 32A EVSE.

2. Also a BEV will charge from a lower rate supply.
So my PHEV will also charge from the 10A max "Granny Charger", just takes longer.

A Smart EVSE with current transformers sounds ideal.

 

[binky]

At moment I am getting negative responses in that it is difficult to couple a wind turbine to a system with Li batteries but dead easy with LA due to the BMS but exactly what the barrier is I have not understood yet.

for some strange reason wind inverters don't seem to be designed to work with Lithium batteries. It might be worth looking at SMA for a possible solution to that.