Remote Solar to Powerwalls

[aesculus]

I have put a reservation in for Tesla solar roof to go on a remote building that is about 200 feet away from my main panel and existing powerwalls and other solar inverters. That circuit is currently fed by a 50 amp breaker and has almost no load on it. It's in a barn with a few non used power plugs and occasionally used lighting.

I am certain that the circuit will hold whatever PV output I am planning so that is not an issue. I also expect that they will have to put disconnects at the new inverter at the remote building but also at the main panel for safety protection. I think that is doable but may need to convince the building department that is OK. There already exists a separate 240V panel in that building so no problem with isolated circuits etc. It's the home run back to the main panel that is an issue.

But my real concern is how Tesla will be able to monitor the solar output to the PWs. It would be one thing if the circuit had no load on it at all. But there will be times, especially when there is no solar production and the lights are used, that their will be a load on that circuit. Hence Tesla would see a negative load. Not sure how that would work. Personally I would not care since it would be minimal and occasional, but it might be an issue for them.

The alternative would be to put loop inductors at the remote building on the solar panel circuit and then wire those back to the main panel. Since that load is so small I think I MIGHT be able to fish a couple of small wires into the existing conduit. Not sure what voltage those are though so if they are not at least 120v I know the building department will not allow that.

Has anyone else put solar in a remote building back to PWs as I have described above?

 

[JPP]

You can install a Neurio current transformer remotely at the PV and run a data cable back to the Tesla gateway, which has an input for the remote CT on the 'built in' CT (at least on my gen. 1 TEG.). But caution that you are not supposed to run low voltage in the same conduit as high voltage.

 

[pilotSteve]

FYI, I am doing a (somewhat) similar project, with 11.8 kW (36 300W qcells) on the roof my horse stable and 38 kWh of battery inside the horse stable outbuilding. It requires 180 feet of trenching and three buried conduits to the main-panel. Costs quote is:

$2,600 180 feet of 24" deep trenching
$5,100. Buried conductors and 3 conduits laid in trench

Also of course requires 100A sub panel, 150A main breaker panel, Channel strut mounting in Stable ($1000), etc.

Custom (remote) installations are expensive! But it keeps the batteries, panels and equipment away from the house where it would be visible, and also gives us power in the stable where we had none before.

 

[aesculus]

But caution that you are not supposed to run low voltage in the same conduit as high voltage.

Yeah. That is the gist of the problem. Not sure if there is a wireless equivalent or even better wifi, since I have that in both locations.

 

[BGbreeder]

You could consider adding a Yagi antenna to the WiFi in the barn and point it back to the house. FWIW: You may want to bear in mind that Ethernet technically has a 100m limit due to network timing, and that at long(er) distance, you may want to have a bridge repeater isolating the barn network.

All the best,

BG

 

[Vines]

You can install a Neurio current transformer remotely at the PV and run a data cable back to the Tesla gateway, which has an input for the remote CT on the 'built in' CT (at least on my gen. 1 TEG.). But caution that you are not supposed to run low voltage in the same conduit as high voltage.

Low voltage can go in the same conduit as conductors, just need the proper wire.

600V, double shielded stuff by Belden works wonders. You just get wifi to the barn and use a neurio meter and you are set.

Technically the new CT meters have a 300' limit, so you might just be able to extend them without any other fuss, if you have access to pull through a conduit.

 

[aesculus]

Low voltage can go in the same conduit as conductors, just need the proper wire.

600V, double shielded stuff by Belden works wonders. You just get wifi to the barn and use a neurio meter and you are set.

Technically the new CT meters have a 300' limit, so you might just be able to extend them without any other fuss, if you have access to pull through a conduit.

I have access to the conduit and it has breaks about every 50 feet so hopefully fishing will not be too much of an issue. It's a 2" conduit and I think the conductor in their is a 2, but need to verify.

I guess I will see what Tesla has to say and then make my case with your double shield conductor with the county building department.

 

[Vines]

As long as the wire is rated at 600V, then it can be in the same conduit as conductors.

Tesla has this same cable, and have given the part number out to installers. Whether or not they are interested in your non-standard install is up to them.

 

[aesculus]

Whether or not they are interested in your non-standard install is up to them.

I am polishing up my sales hat as we speak.

I fully expect a condition for the project is that I provide the installation of the signal conductor in the conduit pre engagement.

 

[Vines]

I am polishing up my sales hat as we speak.

I fully expect a condition for the project is that I provide the installation of the signal conductor in the conduit pre engagement.

Good luck. PM me if it doesn't work out and you want a referral.