Model Y Home charging using Wall connector + Tesla Solar Panel + Power wall combo

[Sundar]

I have recently got Tesla MY and had wall connector installed from old Main panel. Tesla moved all the controls to new panel and kept the old one as backup relay when they installed solar + powerwall.

I already have Tesla solar panel + 1 power wall. But unfortunately Tesla guys did not add any breaker switches for wall connector though I told them I will be buying a electric car soon. then, I found a local electrician and he added two breaker switches to old Main Electrical panel and said it would use the solar power first then power wall and then finally from grid if other sources does not have enough energy.

But based on my usage I found its always taking it from grid and not from solar or power wall. So when I asked my electrician he can move the breaker switches to new panel ( have dryer switches and not used as I have gas dryers). He is saying additional $170 for fixing that.

On a side, I reached out to Tesla and asked why they did not add breaker switches for car as I specifically mentioned I will be buying car soon and they are saying it depends on the system design and system size only they can add breaker switches. Now they can install for very high cost like $1500 and if other technician touches the new panel then tesla solar systems warranty will be void or something. Any help appreciated how to use the solar then power wall for my car charging when energy is available then on the grid ( just like entire home is using), night times it uses from power wall. Any input/experience would be appreciated.

 

[jjrandorin]

Any help appreciated how to use the solar then power wall for my car charging

Using solar to charge your car, your system will need to have CTs on it that allow it to see that load. Its unlikely that it was done that way since you had "an electrician" come and move the breaker switches. Once you get the CT situation straightened out, then your system will see solar and if you charge your car, provide power to it while the solar is running and you are charging during that time.

A wall connector in general is a 60amp load, so yes, it does depend on system design whether they can or will include such a load. You coiuld have informed them you would be happy with whatever size 240 breaker they could put in for vehicle charging, but that would have required you to discuss that with them and tesla doesnt tend to discuss installs much with homeowners.

Ditch the idea on charging your car from powerwalls, since its (basically) using 1 AA battery to charge 4 D batteries. It doesnt make any sense at all to try to charge a vehicle with a 60-75 kW battery with a battery that has 13.5kW, which is what you are doing if you try to charge your car from powerwall energy.

 

[Sundar]

I see, can electrician add the CT and get the wall connector charge it from solar during the day. How do I sort this out? I see it does not make sense to use the power wall for charging as car requires more power. Thanks for enlightening me on this. I am still new to all these.

 

[jjrandorin]

I see, can electrician add the CT and get the wall connector charge it from solar during the day. How do I sort this out? I see it does not make sense to use the power wall for charging as car requires more power. Thanks for enlightening me on this. I am still new to all these.

The "CT" (either current transformer or current transducer, not sure on the acronym) is a clamp that goes around circuits to measure throughput. It goes around load circuits and then gets connected to your solar equipment.

Since there are settings that need to be set in your solar equipment, you need an electrician that is comfortable not only installing the CT but plugging it into your solar equipment, and configuring said solar equipment (so no, you cant get a random electrician, you need at a minimum an electrician that installs solar systems and has access to contact tesla to configure the tesla system, or, in other words, a tesla solar electrician).

 

[Sundar]

ok, got it. the tesla certified electricians or tesla solar electrician can only do that then?

 

[jjrandorin]

ok, got it. the tesla certified electricians or tesla solar electrician can only do that then?

I cant give you a definitive answer on that ( I am not a tesla employee, nor affiliated with Tesla in any way other than owning these products like many others), but in general the answer would be "yes, you need an electrician that is familiar with Tesla's systems, and also is able to either edit the CT configuration in your equipment or contact tesla and inform them of the setup on your behalf."

In a practical sense, this means if Tesla installed your system, you need Tesla to do it, and if you had a third party installer for your system, you need that third party to do it. In the solar / PV space, no one really touches someone elses install, for liability reasons.

 

[Sundar]

gotcha. I had tesla installed my system and they are saying $1500 for installing wall connector on the new Panel with CT to add couple of breakers

 

[Rocky_H]

In the solar / PV space, no one really touches someone elses install, for liability reasons.

Well, this is a bit more common. I just hired a local solar company to remove my entire system and later come back and reinstall the whole thing so that a different company could get in there to replace our roof shingles. Our original solar company had gone out of business, so this kind of piecemeal work or standalone repair jobs is becoming a thing in the industry.