Question for Solar Charging Guru's

[Sparkeur]

We live most of the year in the SW of France. I have a Model 3P and we are about to buy a YLR. Having made this investment in EV's, I am wondering about setting up a solar powered infrastructure to charge them. Our garage is a structurally sound Charentaise building with an east facing roof area of 65 sq metres and a west facing one of 90 sq metres. We get a lot of sun! At the moment I am only interested in being able to charge the cars, not provide power to the house. I have searched but can't find any system solely for EV charging...unless I'm looking in the wrong place. Can the tech brains on this forum provide any advice?

 

[Dilly]

We live most of the year in the SW of France. I have a Model 3P and we are about to buy a YLR. Having made this investment in EV's, I am wondering about setting up a solar powered infrastructure to charge them. Our garage is a structurally sound Charentaise building with an east facing roof area of 65 sq metres and a west facing one of 90 sq metres. We get a lot of sun! At the moment I am only interested in being able to charge the cars, not provide power to the house. I have searched but can't find any system solely for EV charging...unless I'm looking in the wrong place. Can the tech brains on this forum provide any advice?

If you are looking for just a stand alone setup, I.e. not connected to the grid or house, it may be a bit of a poison chalice. Unless you throw in a battery.
Any power you produce will of course go to the cars but when satisfied, the panels will just shut down. A battery will soak up excess which can go to the cars at night, but they are expensive.
If you have a lot of sun, panels only that shut off may be right for you but you could also use any excess in the house rather than just shutting down.
it perhaps comes down to simplicity and price

 

[WannabeOwner]

At the moment I am only interested in being able to charge the cars, not provide power to the house

Is there a technical reason (or some Red Tape in France maybe) which means you can't just route the generated electricity to the house and then "whatever you plug in" would use it (i.e. including charging the cars). I'll assume you would have access to some sort of car charger that could monitor PV production and change the car AMPs accordingly (e.g. if a cloud comes over) so you don't draw from the grid.

 

[phil4]

I think Victron do "off grid" inverters. If you have one of them, you can create a solar powered cirtcuit, distinct from the house, and power your car chargers from that. I suspect you'll still want a "solar" aware charger, like Zappi, Hypervolt (I think), so that they deliver the right amount at the right time.

 

[Llama.]

Why don’t you want to power your house with solar? Is it because of cost or is this just the issue you are interested in?

I ask because the cheapest and technically easiest way to charge your car with solar PV is to just get a normal household solar panel set up. And then get something like a MiEnergy Zappi car charger that automatically begins to charge your car when your panels are producing excess solar.

Off grid systems that don’t power your house aren’t worth it.

My solar panels are set to charge up my house battery first each day. Then my car starts to charge at about noon until sunset. I get about 40 miles a a day and a full storage battery each day in the summer doing this.

 

[Sparkeur]

Thank you all for your responses. In France, solar power has turned into the replacement windows/conservatory pressure selling that the UK suffered from in the '90's. '1€ to install and then become wealthy selling all your electricity back to the grid' type of thing. I've just given up trying to find a straightforward installer. That's why I wondered if there was a stand-alone 'off the shelf' system of solar/battery/charger just for EV's as it seems a logical thing to do. However, maybe the costs just aren't sensible yet.

 

[Dilly]

Thank you all for your responses. In France, solar power has turned into the replacement windows/conservatory pressure selling that the UK suffered from in the '90's. '1€ to install and then become wealthy selling all your electricity back to the grid' type of thing. I've just given up trying to find a straightforward installer. That's why I wondered if there was a stand-alone 'off the shelf' system of solar/battery/charger just for EV's as it seems a logical thing to do. However, maybe the costs just aren't sensible yet.

The energy price hikes last year gave rise to big increases in the cost of panels and batteries as supply was overwhelmed by demand.
The utopia here is to run your house, charge car and batteries and then run on battery at night for no cost. In winter, when solar is poor, using off-peak grid instead of, or to supplement solar. Solar car charging only isn’t a thing unless you have a lot of panels and some aren’t permitted to export.

Solar edge do have a battery system with an inbuilt car charger and of course they do panels and inverters too. @Yachtsman had such an installation though he has had a lot of problems with all of the components not doing what they should when they should.

You are in different environment and French installers play a different game at present. How you approach the right solution depends upon the amount of sun you get during the year, whether your panels will be shaded or not and what the daytime/nightime electricity costs are.

You can see what I have in my signature. from October to March, I buy off peak every day to top up cars and batteries.
The rest of the time I buy about 1KWh per week which is just the result of the Powerwalls balancing against the grid. I have a surplus most days after charging everything.

A Zappi is probably the best solar charger going at the moment.

Your best starting point, is to get a calculation of how much you could generate and work from there to suit your needs. Also consider power cuts if you get them. Solar panels in the U.K. shut down during power cuts for safety unless you have a Powerwall or the latest Givenergy batteries.

I’ve just passed the 10k miles mark on my model 3. fuel costs to date are just £97 because of solar

 

[SageBrush]

OP, tell us about your setup and grid-tie in France. Specifically, how is PV generation not used by your garage/EV/home handled by the utility ?

I presume your garage and home share a service ?

Actually, I suggest you find a PV forum frequented by those in France. It might be a sub-section of this forum, or Google search for what you need. I understand that you came to the idea of PV from EV ownership, but in this case an EV is a load, just like a heater or Jacuzzi or whatever.

 

[Js1977]

Its as @SageBrush said. You are overthinking it a bit. It's just a load. Unless you do the opposite of what most people do (sleep at night and go out and about etc during the day) or you consistently have a very long period at home in the day, then solar on its own just to charge the car is not really feasible imho. However, also as mentioned you will need a charger that plays well with solar and Ill add wallbox to the list given here but would suggest a Zappi as its a bit more expandable, better monitoring and easier to setup.

There are plenty of solutions out there. Just pick an inverter the can either do both on and off grid.

I have recently came across a youtube channel from a British chap living in France building his own system. Ill try finding it again for you.

 

[WannabeOwner]

I've just given up trying to find a straightforward installer

Sorry to hear that.

something like a MiEnergy Zappi car charger that automatically begins to charge your car when your panels are producing excess solar.

Will that detect "Excess PV" or does it need to be able to detect "Grid export" to start car charging? (IDK, just curious)

 

[phil4]

Will that detect "Excess PV" or does it need to be able to detect "Grid export" to start car charging? (IDK, just curious)

In normal use it'll detect excess PV by detecting Excess export (ie it can tell whether you're sucking juice in, or pushing it out). It just uses a few CT clamps to do that. It'll need 1.4kW exporting before it starts charging (though you can change by allowing it to suck in a proportion of the grid to get to that).

The issue with not connecting to your house isn't a common one almost no one in the UK wants to do it. But the technical issue is the frequency of the power. When grid tied they can use the grid to get their frequency. Hence you need something more specialised, and as I mentioned Victron do those. Once you go down that rabbit hole, you'll find that some even accepted generator input.

 

[tsh2]

Disappointing news about the installers since I was also planning to install solar in the south of France. I suspect that unless you can find value in most of the generated electricity (car, house or export), you won't have a very cost effective solution (although I don't know what prices are expected to do in France). The advantage of connecting to the grid is that it functions (financially) as an inefficient battery so it matters less when you have a load to run. Interested to know your eventual solution.

 

[Sparkeur]

Is there a technical reason (or some Red Tape in France maybe) which means you can't just route the generated electricity to the house and then "whatever you plug in" would use it (i.e. including charging the cars). I'll assume you would have access to some sort of car charger that could monitor PV production and change the car AMPs accordingly (e.g. if a cloud comes over) so you don't draw from the grid.

Thank you so much for all your responses. The reason why we wouldn't route to the house is that the garage block is quite a distance from the main house and the whole plot is, as you would expect from a 300+ year old property, haphazard It's really only the garage block that lends itself to a PV installation. I ask the question because in France, car sharing is a 'big thing' and the government has built many parking places by main roads and motorways with solar roofs and charging for EV's. There are also a number of home/office solar parking garages coming on to the market but they are short on detail. At the moment, I use a 32A commando style socket linked to the Jedlix app which has worked well for 3 years or so and may well continue to do so when our next EV arrives. I was just curious to see if there were any dedicated systems available.

 

[SageBrush]

The reason why we wouldn't route to the house is that the garage block is quite a distance from the main house and the whole plot is, as you would expect from a 300+ year old property, haphazard

Hmmm.

Is your connection between the home and garage single or 3 phase ?

 

[WannabeOwner]

the whole plot is, as you would expect from a 300+ year old property, haphazard

We had a place in France, over generations it had been split amongst siblings. The barn next to the house was "someone else's" and our barn was "somewhere else" - which will come as no surprise to you, I'm sure . It also had Live/Neutral swapped at the point the power came into the property - also not unuual in France of course, but foxed me with my little 13 AMP plug-checker-gadget in the days before Internet Knowledge.

he government has built many parking places by main roads and motorways with solar roofs and charging for EV's

I read that they have mandated adding PV above all car parks. Hope that won't mean that roof-trained Plane trees are replace with concrete pillars ...

 

[Sparkeur]

Hmmm.

Is your connection between the home and garage single or 3 phase ?

The whole house is single phase - in a French sort of way.

We had a place in France, over generations it had been split amongst siblings. The barn next to the house was "someone else's" and our barn was "somewhere else" - which will come as no surprise to you, I'm sure . It also had Live/Neutral swapped at the point the power came into the property - also not unuual in France of course, but foxed me with my little 13 AMP plug-checker-gadget in the days before Internet Knowledge.

Our original cadastre is dated 1730 with numbered plots and even then, old buildings all over the place. I'm convinced that the plot of the field next to us, in which vines grow, actually extends about halfway into our kitchen where presumably, the brother of the great-great-great uncle once housed his cattle and, as you correctly state, subsequent generations divided everything up.

We have a total of five consumer panels dotted around various buildings. Somehow, it all seems to work....

 

[Mrklaw]

cable is good with haphazard if run carefully. If its not really really far I'd still consider trying. That roof sounds massive to waste on just charging a car - could easily provide your home energy including heating and export to the grid if thats a thing that can provide some income in France

 

[WannabeOwner]

I tried PVWatts calculator for Nouvelle Aquitaine

East 65sq.m.:

Month	Solar Radiation ( kWh / m2 / day )	AC Energy ( kWh )
January	1.22	296
February	1.85	417
March	3.06	765
April	4.17	988
May	4.68	1,126
June	5.29	1,213
July	5.29	1,241
August	4.66	1,094
September	4.03	935
October	2.42	591
November	1.47	346
December	1.04	251
Annual	3.27	9,263

West 90 sq.m.

Month	Solar Radiation ( kWh / m2 / day )	AC Energy ( kWh )
January	1.24	413
February	1.89	581
March	3.06	1,041
April	4.17	1,344
May	4.72	1,550
June	5.43	1,701
July	5.56	1,784
August	4.68	1,495
September	4.04	1,277
October	2.35	778
November	1.51	486
December	1.04	342
Annual	3.31	12,792

If you used it all that looks like about 5,000 miles / 9,000 km p.a.

 

[Mrklaw]

if thats about 22,000 kwh annual generation, at 3m/kwh that'd be 66,000 miles p/a, or 106,000 km?

or enough to drive 15000 miles a year (5000kwh), run an average sized house (3000kwh), and heat the home, cool the home and heat your hot water (another 3000kwh maybe).

And the same for your neighbour

 

[WannabeOwner]

if thats about 22,000 kwh annual generation, at 3m/kwh that'd be 66,000 miles p/a,

No idea where I got my figures from ... sorry about that!