South Easter

Have a similar set up, but am using almost no external power to heat water except on very overcast/rainy days. So I think there is definitely a problem somewhere in your system. 
Have easily reached 60-65 degrees in the last few sunny days in Cape Town - now with rain and cloud may need some external heating.
 
In summer temperatures are even higher and I occasionally shield some of the tubes. 
 
Should not lose more than 3-4 degrees overnight if the geyser is well insulated.

Have a similar set up, but am using almost no external power to heat water except on very overcast/rainy days. So I think there is definitely a problem somewhere in your system. 
Have easily reached 60-65 degrees in the last few sunny days in Cape Town - now with rain and cloud may need some external heating.
 
In summer temperatures are even higher and I occasionally shield some of the tubes. 
 
Should not lose more than 3-4 degrees overnight if the geyser is well insulated.

Maybe my experience as a novel electric vehicle owner will be useful to you.
I bought a BMW i3 approximately two months ago. Many reasons for that: my old car was getting on in years, I wanted to reduce my carbon footprint, I wanted to make better use of my solar generating capacity and who can resist the lure of a new big toy... Definitely not a money saving endeavour as yet, but then a hobby does cost.
Thus far I am very happy with the car - a completely new driving experience. I am really enjoying it.

I run a grid tied/  hybrid solar system (SMA Sunnyboy + Sunny Island) together with 16 kWh of BlueNova batteries. I in fact added an extra 8 kWh to help me charge my vehicle. I have 3.96 kWp of solar panels on the roof. That is near the limit of what I can accommodate in a relatively north facing direction.
Being single my daily consumption ran around 8 to 10 kWh prior to having the electric vehicle (I have converted to a solar geyser, gas hob, LED lighting, low-power pool pump et cetera). I could therefore definitely produce more electricity than I was consuming and I wanted to put this electricity to good use.
I am at work most of the day, so am actually not able to charge with solar directly except over weekends or if I'm lucky enough to get home before the sun has set. Luckily, my daily commute is around 20 km only. That means I only have to recharge the battery by approximately 2 to 5 kWh on a daily basis, depending if I do any other trips. (It is up and down the mountain!) 
I am also very lucky in that the shopping centre very near my house (literally two minutes down the road) has recently installed a DC fast charger. I therefore always have a backup option if I need to get the battery full quickly or return from a long trip with an empty battery. Daily charging I manage from stored battery capacity or do over the weekend when I'm at home.
The BMW can be programmed to charge immediately or to charge later at set times that you can select. You can also vary the charging current. The standard charger supplied with the vehicle charges at a current of  10 A. You can reduce that I think to a minimum of around 6 to 8 A. With second party chargers you can charge up to 15 A from a standard plug. If you want faster charging rates you need to invest in a wall box or similar equipment. That is of course if you use electricity from the grid. With a standard solar setup I think you will be limited to the slower charging rates (with the current of around 8 to 10 amp) as you will otherwise require a lot of panels and very large inverted to produce for instance 10 kW of power. That of course means that if the battery is completely empty it will take you a very long time to charge.
I schedule charging for the early morning hours when there are no other competing demands on the electrical supply. The inverter and batteries can happily supply the required current. This works very well for me and I leave home with a 100% charged battery every morning. Thus far I am simply using the charger supplied with the car and have not felt the need to upgrade to a faster solution, especially since I do have the DC charging backup.
My one concern with a totally off grid solution with no battery (and I am definitely no expert) is whether the car's charging system will be happy with a fluctuating power delivery as is often the case with solar production. I am worried that the charging may be interrupted due to  the software in the car detecting what it interprets as a grid error when your solar output drops from a passing cloud. Either you would need to use a very low charging current so that your production always exceeds the demand during charging (but then you are basically throwing a lot of potential power away) or you may need to have a system with a relatively small battery that can supplement and keep the power delivery steady.

I know that a fair number of consumers in Europe are using solar for charging, but my understanding is that it is mainly in the setting of a grid tied solution. This will of course guarantee a steady delivery of power to the car during the charging process.
Just my experiences and thoughts.
 
 

I use these covers. 
Essentially they are piping sawn in half. They fit standard EV tubes and work well.
 
https://www.sustainable.co.za/geyserwise-evacuated-tube-cover-set-of-4.html

I take the point on the carbon footprint generated by using Eskom to charge - thus far I have managed to keep it to a minimum and estimate that more than 90% of charging was from solar. But it is still good to have a plan B

Maybe my experience as a novel electric vehicle owner will be useful to you.
I bought a BMW i3 approximately two months ago. Many reasons for that: my old car was getting on in years, I wanted to reduce my carbon footprint, I wanted to make better use of my solar generating capacity and who can resist the lure of a new big toy... Definitely not a money saving endeavour as yet, but then a hobby does cost.
Thus far I am very happy with the car - a completely new driving experience. I am really enjoying it.

I run a grid tied/  hybrid solar system (SMA Sunnyboy + Sunny Island) together with 16 kWh of BlueNova batteries. I in fact added an extra 8 kWh to help me charge my vehicle. I have 3.96 kWp of solar panels on the roof. That is near the limit of what I can accommodate in a relatively north facing direction.
Being single my daily consumption ran around 8 to 10 kWh prior to having the electric vehicle (I have converted to a solar geyser, gas hob, LED lighting, low-power pool pump et cetera). I could therefore definitely produce more electricity than I was consuming and I wanted to put this electricity to good use.
I am at work most of the day, so am actually not able to charge with solar directly except over weekends or if I'm lucky enough to get home before the sun has set. Luckily, my daily commute is around 20 km only. That means I only have to recharge the battery by approximately 2 to 5 kWh on a daily basis, depending if I do any other trips. (It is up and down the mountain!) 
I am also very lucky in that the shopping centre very near my house (literally two minutes down the road) has recently installed a DC fast charger. I therefore always have a backup option if I need to get the battery full quickly or return from a long trip with an empty battery. Daily charging I manage from stored battery capacity or do over the weekend when I'm at home.
The BMW can be programmed to charge immediately or to charge later at set times that you can select. You can also vary the charging current. The standard charger supplied with the vehicle charges at a current of  10 A. You can reduce that I think to a minimum of around 6 to 8 A. With second party chargers you can charge up to 15 A from a standard plug. If you want faster charging rates you need to invest in a wall box or similar equipment. That is of course if you use electricity from the grid. With a standard solar setup I think you will be limited to the slower charging rates (with the current of around 8 to 10 amp) as you will otherwise require a lot of panels and very large inverted to produce for instance 10 kW of power. That of course means that if the battery is completely empty it will take you a very long time to charge.
I schedule charging for the early morning hours when there are no other competing demands on the electrical supply. The inverter and batteries can happily supply the required current. This works very well for me and I leave home with a 100% charged battery every morning. Thus far I am simply using the charger supplied with the car and have not felt the need to upgrade to a faster solution, especially since I do have the DC charging backup.
My one concern with a totally off grid solution with no battery (and I am definitely no expert) is whether the car's charging system will be happy with a fluctuating power delivery as is often the case with solar production. I am worried that the charging may be interrupted due to  the software in the car detecting what it interprets as a grid error when your solar output drops from a passing cloud. Either you would need to use a very low charging current so that your production always exceeds the demand during charging (but then you are basically throwing a lot of potential power away) or you may need to have a system with a relatively small battery that can supplement and keep the power delivery steady.

I know that a fair number of consumers in Europe are using solar for charging, but my understanding is that it is mainly in the setting of a grid tied solution. This will of course guarantee a steady delivery of power to the car during the charging process.
Just my experiences and thoughts.
 
 

Maybe my experience as a novel electric vehicle owner will be useful to you.
I bought a BMW i3 approximately two months ago. Many reasons for that: my old car was getting on in years, I wanted to reduce my carbon footprint, I wanted to make better use of my solar generating capacity and who can resist the lure of a new big toy... Definitely not a money saving endeavour as yet, but then a hobby does cost.
Thus far I am very happy with the car - a completely new driving experience. I am really enjoying it.

I run a grid tied/  hybrid solar system (SMA Sunnyboy + Sunny Island) together with 16 kWh of BlueNova batteries. I in fact added an extra 8 kWh to help me charge my vehicle. I have 3.96 kWp of solar panels on the roof. That is near the limit of what I can accommodate in a relatively north facing direction.
Being single my daily consumption ran around 8 to 10 kWh prior to having the electric vehicle (I have converted to a solar geyser, gas hob, LED lighting, low-power pool pump et cetera). I could therefore definitely produce more electricity than I was consuming and I wanted to put this electricity to good use.
I am at work most of the day, so am actually not able to charge with solar directly except over weekends or if I'm lucky enough to get home before the sun has set. Luckily, my daily commute is around 20 km only. That means I only have to recharge the battery by approximately 2 to 5 kWh on a daily basis, depending if I do any other trips. (It is up and down the mountain!) 
I am also very lucky in that the shopping centre very near my house (literally two minutes down the road) has recently installed a DC fast charger. I therefore always have a backup option if I need to get the battery full quickly or return from a long trip with an empty battery. Daily charging I manage from stored battery capacity or do over the weekend when I'm at home.
The BMW can be programmed to charge immediately or to charge later at set times that you can select. You can also vary the charging current. The standard charger supplied with the vehicle charges at a current of  10 A. You can reduce that I think to a minimum of around 6 to 8 A. With second party chargers you can charge up to 15 A from a standard plug. If you want faster charging rates you need to invest in a wall box or similar equipment. That is of course if you use electricity from the grid. With a standard solar setup I think you will be limited to the slower charging rates (with the current of around 8 to 10 amp) as you will otherwise require a lot of panels and very large inverted to produce for instance 10 kW of power. That of course means that if the battery is completely empty it will take you a very long time to charge.
I schedule charging for the early morning hours when there are no other competing demands on the electrical supply. The inverter and batteries can happily supply the required current. This works very well for me and I leave home with a 100% charged battery every morning. Thus far I am simply using the charger supplied with the car and have not felt the need to upgrade to a faster solution, especially since I do have the DC charging backup.
My one concern with a totally off grid solution with no battery (and I am definitely no expert) is whether the car's charging system will be happy with a fluctuating power delivery as is often the case with solar production. I am worried that the charging may be interrupted due to  the software in the car detecting what it interprets as a grid error when your solar output drops from a passing cloud. Either you would need to use a very low charging current so that your production always exceeds the demand during charging (but then you are basically throwing a lot of potential power away) or you may need to have a system with a relatively small battery that can supplement and keep the power delivery steady.

I know that a fair number of consumers in Europe are using solar for charging, but my understanding is that it is mainly in the setting of a grid tied solution. This will of course guarantee a steady delivery of power to the car during the charging process.
Just my experiences and thoughts.