Optimise charging with solar panels…

Solar is great. I had a 1.4kw lithium battery and 200w panels. Took all day to fill the battery with sun energy. It wasn't much, but felt great to actually take energy from the sun and put it into the car. However, I don't think you did the math on this unless you live on a large lot and effectively solar canopy-ized your entire property. At least in my area, the advantage of solar at home is to reduce your kw cost to the lowest and whatever energy you currently aren't using you sell to the electric company.

I live en Europe and unfortunately provider only buys the electricity at 1/14 price so extremely unbeneficial to sell it back and thus I wanted to optimise my consumption. I expect to produce 3 times the house needs during summer months.

In general level 1 and 2 charging has not been reported to cause any additional degradation to the battery in a Tesla.  Even level 3 supercharging is said to cause negligible degradation to the battery, so that's not the issue.  There's an efficiency issue in which charging at level 1 is actually less efficient as the lower charge rate is coupled with drain from the Tesla needing to keep the computer on and working while charging is happening.  I think 300w is what I've seen most reported, so just know that the vehicle computer is eating into your solar production while you're charging, so depending on what your system is able to produce at peak time minus what the home is consuming minus about 300w would let you know what's actually going into the vehicle. Still, any overage going into the vehicle vs the grid is a bonus when you don't have to pull off at 14x the price you get paided to put in.

Thanks, this was very useful, my biggest fear was how the car/battery handles the constantly changing charging rate.

Unless I misunderstood something about your setup, the Tesla isn't going to fluctuate at all.  Are you totally off the grid? Only using what you produce? The Tesla is going to charge whatever you've set it at, regardless.  If it needs to supplement from the grid to maintain that, it will.  If you only want to use your solar, you're going to have to do the math and figure out what level you can charge at, and for how long before it loses full power and starts to tap the grid to maintain that charge state.  A whole home battery like the Powerwall can store that excess for use later so you can meter it out while the solar isn't producing, but that's a whole other topic and price.

I am not off grid but as far as I understand Charge HQ app will monitor my solar production and send a signal to Tesla to pick up the energy produced. Edit: so my whole point is that I expect to produce much more than what the house will need during summer month so I’d like to optimise my charging as much as I can as it is extremely unbeneficial to sell the excess energy and charge from grid.