EV charging and solar power

matty2767

Hi guys

We recently got a Nissan Leaf with the 6.6 on board charger and have had the 7kw pod point installed too. This morning we were generating 3.2kw through the panels, the car was on charge and dishwasher was on but we were still putting 2.5kw into the hot water via the diverter.


For those of you with Leafs, is it normal for the Leaf down the charging rate above 85% charge? [I haven't looked at the comparison when it is more empty than that]. I was expecting to completely use all my generation for charging the car. Or is the pod point installed so it doesn't take any generation from the panels ie. outside the circuit that the rest of the house has.


edit: actually the electricity meter light is flashing on and off very fast so I guess the car isn't drawing anything from the panels at all is it possible to install the pod and not have the solar generation be used at all?

thanks

Matt

EricMears

Can't really help with a leaf but FWIW, my VW e-Up! is normally set up to charge only during E7 hours and I need to adjust that on the rare occasions when it's sunny enough to have surplus power, we don't need to wash clothes or dishes and we aren't actually out in the car.

There are also other charging parameters I could alter so that (say) it charges immediately rather than waiting for E7 if battery below a certain %full or stops charging when battery reaches a certain %full. I tend to ignore all those options.

matty2767

Thanks Eric

When you charge in the day does the VW draw charge from your panels though? Mine doesn’t, it is pulling it all from the grid for some reason. It’s like the charge point is wired outside the solar pv circuits.

Thanks

Matt

michaels

We charge our leaf using the 'granny cable' plugged into a standard socket which draws about 2.2kwh I think pretty much up to 100%. We just plug in when the panels are likely to make over 2kw which is about 11-6 with our just S of W panels.

We have set the charge to stop at 80% unless we are expecting to use more as keeping below 80% and above 20% is supposed to increase the longevity of the battery.

Dave_Fowler

The import meter reads the nett energy use. There is no way the Pod Point can not be using the energy from the panels and only using the grid.

If the panels are producing 3.2kW and you're putting 2.5kW into the immersion then there's only 0.7kW spare ignoring other use within the house (Dish-washer was on too? - another 2kW?)

All-in-all you could well have been using 2.5kW (immersion), 2kW (dishwasher) and 6.6kW (Pod Point). No wonder the light was flashing fast. If you were only producing 3.2kW from the panels, you'd be importing 7.9kW ignoring any base-load of the house.

In my car (Hyundai), I can set the charge rate from the Pod Point to either 6.6kW or 3.3kW or I can use the 'Granny Charger' and set it to 2.2kW, 1.2kW or 800W. I can use the Pod Point overnight on economy 7 or the GC during the day to use excess from the panels. I plug the GC into the auxilliary socket (non-proportional) on the immersion heater controller.

Dave F

Dave_Fowler

Just a thought - When my Pod Point was installed, it was connected to a new terminal block in the cable between the import meter and the consumer unit. The immersion heater controller current clamp was connected immediately after the consumer unit and before the terminal block. So the current clamp for the immersion did not measure the current used by the Pod Point. I had to move the clamp from its old position to the cable between the new terminal block and the import meter.

If your Pod Point is the same, this could account for the immersion controller still taking current even though there was a nett import through the meter.

Dave F

matty2767

HI Dave

agree with what you say but if the car was charging as we expect it to ie. pulling more than I can generate, then I shouldn't be diverting anything to the hot water. which is what happens should I say, put the kettle on. the diverter stops divetting

thanks

matt

Dave_Fowler wrote: »

The import meter reads the nett energy use. There is no way the Pod Point can not be using the energy from the panels and only using the grid.

If the panels are producing 3.2kW and you're putting 2.5kW into the immersion then there's only 0.7kW spare ignoring other use within the house (Dish-washer was on too? - another 2kW?)

All-in-all you could well have been using 2.5kW (immersion), 2kW (dishwasher) and 6.6kW (Pod Point). No wonder the light was flashing fast. If you were only producing 3.2kW from the panels, you'd be importing 7.9kW ignoring any base-load of the house.

In my car (Hyundai), I can set the charge rate from the Pod Point to either 6.6kW or 3.3kW or I can use the 'Granny Charger' and set it to 2.2kW, 1.2kW or 800W. I can use the Pod Point overnight on economy 7 or the GC during the day to use excess from the panels. I plug the GC into the auxilliary socket (non-proportional) on the immersion heater controller.

Dave F

matty2767

mmm. I think mine might be the same. are you saying that by having the iboost after the new terminal block and on the cable to the consumer unit the ibosst can think it has spare elec and divert to the hot water but immediately after the charge point is asking for power. therefore the iboost is using all the solar whereas it should stop diverting because the car needs it but it isn't far enough along the chain to detect the pull from the charge point. sorry this is rubbish explanation

I have moved the clamp to that shown on this picture to the furthest cable at the back, the shiny grey cable with the brown sleeve where it joins the new terminal.

Dave_Fowler wrote: »

Just a thought - When my Pod Point was installed, it was connected to a new terminal block in the cable between the import meter and the consumer unit. The immersion heater controller current clamp was connected immediately after the consumer unit and before the terminal block. So the current clamp for the immersion did not measure the current used by the Pod Point. I had to move the clamp from its old position to the cable between the new terminal block and the import meter.

If your Pod Point is the same, this could account for the immersion controller still taking current even though there was a nett import through the meter.

Dave F

Dave_Fowler

You are correct. The clamp for the Iboost should be after between the Pod Point connection and the power input to your house.

From what I understand from your photograph, you have probably moved the clamp to the correct position. (I can't actually make out where the Pod Point is connected). The clamp can be either before or after the import meter, but must be on the import side of all the circuits related to the household load.

Remember the clamp is 'directional' so you may have to turn it over so that the current through it is in the correct direction otherwise it will divert to the immersion when there is no spare power and cut it off when there is spare power!

Dave F

EricMears

matty2767 wrote: »

Thanks Eric

When you charge in the day does the VW draw charge from your panels though? Mine doesn’t, it is pulling it all from the grid for some reason. It’s like the charge point is wired outside the solar pv circuits.

Thanks

Matt

Very rare that I bother to charge in the daytime (I like it to be fully charged in the morning ready for use during the day) but when I do then it's just part of the total household load and for instance plugging in the car would reduce anything that Immersun diverted to heating.