"Looking for a PV and EV solution"

Wobblydeb wrote: »

No, not too simplistic, and it would work to utilise a good chunk of the electricity you generate. I think the main drawback to the granny cable solution is that it takes much longer to charge. 7-10 hours to fully charge a Leaf, depending upon version. BUT ..... if you are only driving a few miles a day then you will not need a full charge every day. The problem will come if you for instance, go out in the morning and back at lunch time with an empty battery and then want to go out again in the afternoon / evening.

A dedicated 32A car charger will bring that time down to 4-6 hours. It will always pull 32A though, so will be using grid electricity a lot of the time.

The Zappi is ahead of a standard charger by being more flexible - so you can get a quicker charge if needed, or alternatively just use exactly what is available from your panels.

Thanks Wobbleydeb, I have to confess to being sorely tempted as it seems to offer much more than a standard EV charger.
I maybe trying to have my cake and eat it but, picking up on a post from Martyn1981 some time ago I also wonder if the process couldn't be reversed, so that we could use a small percentage of the charge to service our overnight domestic requirements. Perhaps 2-3kwh's worth!
I did pluck up courage and asked the question of Zappi but unfortunately this doesn't appear to be on the horizon at present! It would certainly solve the problem of purchasing separate storage battery/s for this purpose! I reckon Martyn and I would be first in the queue for such a gizmo!

In the meantime I have to come to terms with actually purchasing an EV. Not easy with a lifetimes experience of the oily stuff. But slowly does it and I have to confess to booking a test drive in one of the new Leaf's. Just testing mind!

Dave_Fowler wrote: »

Not only do you have to have a compatible charger if you wish to use the car as an energy source, but you also need a compatible car. i.e. one which has a connection capable of reverse flow - out of the car. I don't think any of the current main stream cars can do this yet.

Dave F

Thanks Dave, from my very limited understanding that's just about what Zappi said. No doubt naivety on my part, but I find it strange that it's possible to charge a storage battery of a several kwh's and then use when the need arises but not that of a battery in an EV.

It may not be possible now, but surely it must be something industry is aiming for, or am I just being rather selfish!

Really pleased to see you've two members interested in your design. Hope they let us know of progress!

Martyn1981 wrote: »

Hiya. I rang my DNO and got lots of help, but that was years ago. For actual permission the installer has to apply, but hopefully the DNO can let you know (as mine did) if it's a no - but they won't say yes without the application, just a 'minded' response.

For upto 5kWp of panels you'll be OK with a 3.68kW capped inverter. Ideally you want permission for more from the DNO, but once hot, the panel performance will drop to about 80%, so losses won't be so bad, and all the time that generation is poor (early, late, winter, bad weather) it won't matter.

For a split system with say East and West panels then 6kWp on 3.68kW might be fine, but I assume you'll install all panels on the SSE orientation (-20 from south).

Size wise, go as big as possible/sensible. A lot of costs are fixed, whereas the PV panels and the roof railing are pretty cheap, so cost per Wp gets lower as you go bigger. for instance 4kWp might be £6k (£1.50 per Wp), but 6kWp might be £8k (£1.33 per Wp).


On-grid domestic battery storage

Well I've progressed further and would like to settle on a total of 26 panels. 24 on the SSE roof and 2 on the vertical wall of the WSW gable end, total 7.41kwp made up of 6.84 on the roof and 0.57 at gable end.
I have one supplier who has no problem with this, using one inverter while the other is insisting that two are required. He has even sent me a Solaredge download showing 2 x SE3500H inverters.
Strangely when only 24 panels are required of 6.84kwp one is acceptable.

From my understanding of info gleaned from your goodselves then I believe that the SE6000H inverter should cope adequately. While the total panel output might be 7.41. Because they are in different orientations, 90 degrees offset, then this figure will not be seen and with only 80% efficiency once they are hot(as Martyn suggests) then even less likely. From the SolarEdge spec sheet for the SE6000H unit then max DC input is 9300w.
I'm struggling to see a problem with a single inverter but if you know differently then I'm happy to be shown the error of my ways to date!