Solar PV for charging an Electric car - help with system design!

[Emily]

Hey!
I am designing a solar PV tree able to generate 3400kWh annually / has a capacity of 4kW, as the trees will consist of multiple panels I will need to work out the best way to connect these panels to produce the current and voltage I need (the system will be grid tied). This system will be located in an airport where it is possible to implement up to 100 of these trees. I would like to design the system to be capable of charging multiple BEV's in short-stay carparks (the model I am using for design purposes is the Nissan LEAF - 24kWh battery - for airport I can assume most cars will not need a full charge, just a top up, so will assume an average of 14kWh needed for each car) - I'm a little confused by the options - As the PV output is DC and the battery intake is DC would it not make most sense to design the tree for Rapid DC charging (as the capacity is only 4kW I would imagine that would require multiple trees connected to produce this (rapid DC would also be good for fast turn around of cars in the short-stay car park and therefore increased profit) - is this possible and even feasible, would that require a storage unit to cope with potentially multiple DCQC units running at once ? and does this mean I can skip out needing an inverter (but then it would be good to have MPPT so would that work?

or would I have to stick to a fast AC charger (7kW - 22kW), in which case what components would I need? and would it be more cost effective to have a battery or would that not be needed with the grid tied system?

Sorry for so many questions, I'm new to electronics so would really appreciate the help

 

[Richard Burns]

I think you may need to restart from scratch in designing this system.
The output of solar panels is a low output power over a long time, the requirement for a car charging point is high power over a short time.
The two systems are not easily compatible.
To fast charge a Nissan leaf directly from solar panels would require about 150m² of panels (about six times a standard 4kW set up) for one car and the panels would have to be producing at maximum (a rare occurrence in the UK!) so you could charge 16 cars with your maximum capability on bright sunny days.
You would also need to know the availability of fast charging capability for EVs as the majority of charging is done from 230V ac or 400V ac, though the Nissan leaf has got fast charging capability.
The panel systems would need to be configured differently for fast charge dc against slower charging ac.
You would also need to know the throughput of cars as storage would only work if there was time to store the power. Though this would make it easier to supply the chargers with the required output whether DC or AC through an inverter.
With a grid tied system battery storage is generally not viable as excess power would be sent to the grid instead.
Airport cars would also often be left for long periods obstructing charging points so planning would need to be in place to avoid this.

 

[LeeH]

FFS, yet another duplicate thread.

 

[Taylortwocities]

FFS, yet another duplicate thread.

She/he will only get half the replies then.....and half of those won't be right...

 

[PEG]

She/he will only get half the replies then.....and half of those won't be right...

...Whilst the other halfwill be about solar powered sunbeds...me own patent,applies...