Powerwall Automated Load Shedding?

[h2ofun]

Has anyone seen or invented any good ways to shed large electrical loads during a grid failure? Our Powerwall design is going to end up backing up the whole house, since it'd be a huge job to separate our pool and spa equipment onto a separate sub panel.

It would be nice to just have some automation in place to disconnect the pool and spa equipment (50A each) from the household wiring, whenever a grid failure is detected. This seems to be a common thing offered by generator manufacturers. I've seen inexpensive modules from both Generac and Kohler, which open a 50A contactor when the grid goes down. These both rely on a signal from the generator transfer switch though. The Generac solution seems pretty slick, I believe the generator slightly lowers the line frequency and then the downstream load control modules detect this and open their circuits.

I also tried searching for any sort of 50A wireless load control devices that I could integrate with my SmartThings hub, but commercial options only seem to go up to 40A. All of the 50A Z-Wave switches look like science fair projects, with a bunch of components cobbled together in a generic weather-tight box.

It would be cool if Tesla offered some hardware to do this, since it looks like the gateway already has a load shedding signal output. Just need the downstream hardware to ingest that signal and operate some relays/contactors (preferably wirelessly).

ever find a solution?

 

[MJ_CA_2019]

ever find a solution?

I have this on my 3 PW whole home backup.

Lumin® : Responsive Energy Management Platform

Off-Grid Mode lets you tell the system which circuits to protect (or not protect is more key in this case).

 

[aesculus]

I have this on my 3 PW whole home backup.

Lumin® : Responsive Energy Management Platform

Off-Grid Mode lets you tell the system which circuits to protect (or not protect is more key in this case).

Looks interesting but seems like overkill for just controlling a few circuits based on grid state. I guess it would depend on how expensive it is (looks expensive).

My other concern is how to use the wifi/ethernet to control this if the grid goes down? The PWs might cycle off before this system could react. I guess it could be configured to automatically terminate tagged circuits if the grid disconnects and perhaps that window is long enough for the PWs to not trip, or at least recover in the next cycle.

I filled out the form to gain access to the specs so I am sure I will hear from them shortly.

 

[MJ_CA_2019]

Looks interesting but seems like overkill for just controlling a few circuits based on grid state. I guess it would depend on how expensive it is (looks expensive).

My other concern is how to use the wifi/ethernet to control this if the grid goes down? The PWs might cycle off before this system could react. I guess it could be configured to automatically terminate tagged circuits if the grid disconnects and perhaps that window is long enough for the PWs to not trip, or at least recover in the next cycle.

I filled out the form to gain access to the specs so I am sure I will hear from them shortly.

In my case it cost me nothing because I had an agreement with my 3rd party installer that we'd be doing a whole home backup with AC soft starts. They could not get an HVAC contractor to warranty soft start installation on my units so they ate the cost of this solution, which to me was great follow through and standing by their word.

As far as controlling Lumin, it has worked perfectly each time the grid has gone down.
If you need to manually control the circuits, the simple solution is to put your network on a UPS. This is on my list but hasn't been installed yet.
I've had 5 different times that the Grid has gone down in the past year or so. My network equipment rebooted 3 of the 5 times. YMMV

 

[CrazyRabbit]

i thought the gateway had a output to cut non critical loads. if not you could wire a relay to be powered by the non backup loads panel so when the grid goes down it opens the contact to the pool and spa.

 

[RKCRLR]

My HVAC doesn't work during backup and trips the powerwalls. It turns out that the SureStart isn't compatible with my reverse run compressor.
One of the options Tesla is considering is a relay on the HVAC control board to prevent it from trying to start when the powerwalls are in backup mode. My understanding is the relay would be controlled by the Gateway.

 

[dortor4ev]

I have found a partial solution and it’s worked well so far…

you can get a raspberri PI and run the “homebridge” app on the raspberri - there are various plug-ins for homebridge - and one of them is a plug-in for powerwalls - and it will add a switch for Powerwall “on-grid” and Powerwall “off-grid” - given those switches you can have apple homekit automations take other actions when those switches trigger

I have Homekit automations tied to those Powerwall software switches to do some load shedding (my towel warmers, heated floors) and other high demand devices - I also have the automation turn on a couple of Philips Hue lights to “orange” around the house to indicate we’re on battery power…

I have some quibbles, and I’m finding some limits with homekit automation - but it’s working well enough that when we lose PG&E power while I’m asleep at 2 am that the floor heaters don’t drain the batteries before I wake up and can adjust our home usage to extend battery life.

 

[h2ofun]

I have found a partial solution and it’s worked well so far…

you can get a raspberri PI and run the “homebridge” app on the raspberri - there are various plug-ins for homebridge - and one of them is a plug-in for powerwalls - and it will add a switch for Powerwall “on-grid” and Powerwall “off-grid” - given those switches you can have apple homekit automations take other actions when those switches trigger

I have Homekit automations tied to those Powerwall software switches to do some load shedding (my towel warmers, heated floors) and other high demand devices - I also have the automation turn on a couple of Philips Hue lights to “orange” around the house to indicate we’re on battery power…

I have some quibbles, and I’m finding some limits with homekit automation - but it’s working well enough that when we lose PG&E power while I’m asleep at 2 am that the floor heaters don’t drain the batteries before I wake up and can adjust our home usage to extend battery life.

I wonder if I could use any of this stuff to deal with my mini splits. When I lost power at 2:30 am the other morning, my generator kicked in. (PW"S would be the same). I had 5 mini split heads on so after the power was back on from generator, and the timers reset, since the mini splits were on, they were still on. But your comments about would I want them running if I were on batteries is a great point. So you setup I assume works great with something is plugged in a wall socket. Any ideas how I might be able to handle my mini split heating?

 

[dortor4ev]

my setup works great for anything that can be controlled via HomeKit - so that includes thermostats, fans, light switches, wifi plugs, AppleTV's - etc…if it can be controlled via HomeKit - HomeKit allows automation that is triggered by various state changes

the power walls are "presented" to HomeKit as a "switch" in HomeKit - and you can automatic HomeKit such that when "switch Powerwall OffGrid goes 'on'" - then turn off my floor heater a, floor heater b, home heating, plug a, plug b, turn on light "c" and make color orange

I'm certain you can do a similar thing with google home if you can get the power walls to be a google home device.

 

[h2ofun]

my setup works great for anything that can be controlled via HomeKit - so that includes thermostats, fans, light switches, wifi plugs, AppleTV's - etc…if it can be controlled via HomeKit - HomeKit allows automation that is triggered by various state changes

the power walls are "presented" to HomeKit as a "switch" in HomeKit - and you can automatic HomeKit such that when "switch Powerwall OffGrid goes 'on'" - then turn off my floor heater a, floor heater b, home heating, plug a, plug b, turn on light "c" and make color orange

I'm certain you can do a similar thing with google home if you can get the power walls to be a google home device.

If one can get a IR remote that controls the Mini split and get be controlled by homekit, then it should work.

 

[zƬesla]

Or if you have an electronics knack, many mini-splits can be controlled directly. That's the approach I took with RPis and 5 mini-split heads. My concern was PWs draining given how much energy the mini-splits use up for heating in winter; now they'll go off automatically if an outage lasts longer than 10 minutes. I can also control manually via the web; clicking on a unit below allows me to set temp/fan/speed, or I can use the shortcut buttons too for powering all on/off or changing seasons.

 

[Robotpedlr]

Anyone know if a way to control a hot tub (50amp 240) set up with home automation?

I have 2 PW and I would like to have the system shut of my Hot Tub if the power is off for over an hour or so. Our power outages are normally pretty short, so if it is less than XX minutes I dont care...but in case it is longer than a few hours (happens on rare occasions) I would like to have the HT shut off automatically in case I am not home or asleep.

 

[mspohr]

If one can get a IR remote that controls the Mini split and get be controlled by homekit, then it should work.

Cielo Breez Smart Wi-Fi air conditioner controller

 

[mspohr]

I have the same problem as the OP. I have several large non-critical loads located at a long distance from the service entrance and with several sub-panels in between so it is impractical to rewire these separately.
The Leviton load centers might be an option but this would still require a lot of re-wiring expense. Looking for large (50 A, 240 V) relays that could be controlled remotely. Through powerline or wifi (although wifi might be problematic in the case of power disturbances.)
Generac seemed to be working on a solution to enable individual load control but I can't find anything about it now.

 

[RKCRLR]

Anyone know if a way to control a hot tub (50amp 240) set up with home automation?

I have 2 PW and I would like to have the system shut of my Hot Tub if the power is off for over an hour or so. Our power outages are normally pretty short, so if it is less than XX minutes I dont care...but in case it is longer than a few hours (happens on rare occasions) I would like to have the HT shut off automatically in case I am not home or asleep.

I considered doing something to mine but haven't pursued it. Mine has a low amp fuse in the control box that protects the controls. A relay and remote fuse could be installed in its place.

 

[aesculus]

I have the same problem as the OP. I have several large non-critical loads located at a long distance from the service entrance and with several sub-panels in between so it is impractical to rewire these separately.
The Leviton load centers might be an option but this would still require a lot of re-wiring expense. Looking for large (50 A, 240 V) relays that could be controlled remotely. Through powerline or wifi (although wifi might be problematic in the case of power disturbances.)
Generac seemed to be working on a solution to enable individual load control but I can't find anything about it now.

I have the same issues. I might be willing to swap the one sub panel with a more modern controllable one but communications to that panel is going to be a problem. No way to run control wires to it. It is over 250 linear feet of wire through at least 3 breakers and is shielded by 6 building walls that have metal insulation. While wifi would work, not all of the routers/ap have UPS's so that will break during cutovers.

Not sure if the Leviton has a normally open state for their controllable breakers. If so that could potentially work in that when the grid power to their controller went out the designated breakers would trip off. While the wifi could reestablish it would not enable the breakers because the grid state was still off. To net it out it would require both an active grid and active wifi to turn on the critical breakers.

I guess I will do some investigation into this. I have two heat pumps and one hot tub on that sub panel which need to trip off when the PWs are supplying power. There are a few other 110V breakers in that panel that I would like to stay on so they would be normal breakers if they support that, or not normally off breakers.

 

[mspohr]

I have the same issues. I might be willing to swap the one sub panel with a more modern controllable one but communications to that panel is going to be a problem. No way to run control wires to it. It is over 250 linear feet of wire through at least 3 breakers and is shielded by 6 building walls that have metal insulation. While wifi would work, not all of the routers/ap have UPS's so that will break during cutovers.

Not sure if the Leviton has a normally open state for their controllable breakers. If so that could potentially work in that when the grid power to their controller went out the designated breakers would trip off. While the wifi could reestablish it would not enable the breakers because the grid state was still off. To net it out it would require both an active grid and active wifi to turn on the critical breakers.

I guess I will do some investigation into this. I have two heat pumps and one hot tub on that sub panel which need to trip off when the PWs are supplying power. There are a few other 110V breakers in that panel that I would like to stay on so they would be normal breakers if they support that, or not normally off breakers.

Generac was developing a solution which used frequency shift to shed loads. Can't find anything on that now.

 

[Vines]

Here's a possible solution in a manufacturer of relays triggered off 24 or 48vdc control circuits:

Two Pole Mercury Relays or Two Pole Mercury Contactors for 100 AMP Loads or High Voltage Loads

 

[aesculus]

The Leviton load centers might be an option

I did a quick pass on their smart load centers and did not feel these would come close to what we need. First off I saw no way to monitor the grid state and trip breakers appropriately. They allude to the fact that they are looking at extending features later but nothing specific.

Turning to Schneider (Square D) I only saw a collaboration with Kohler to support turning on various breakers when a generator was running. So the opposite of what I need.

 

[Vines]

I did a quick pass on their smart load centers and did not feel these would come close to what we need. First off I saw no way to monitor the grid state and trip breakers appropriately. They allude to the fact that they are looking at extending features later but nothing specific.

Turning to Schneider (Square D) I only saw a collaboration with Kohler to support turning on various breakers when a generator was running. So the opposite of what I need.

I was thinking running control circuitry based on the low voltage relay that already controls the HVAC load shedding. Its a normally closed relay that opens when the grid goes out, if you have it set that way in the app.