Powerwall for Planned Power Outages

[jboy210]

does the app tell you that the grid is down?

The app receives a message. Also, there is a power flow display which shows how much power is coming from and going to grid, solar, powerwall, and home. When the grid is out there is an "X" over the link from the grid.

 

[gpez]

Yes, it sends an app notification. That's great if you are awake but you might not notice it if you are asleep.

Some UPS devices will also beep if the Powerwalls are outputting too high of a frequency. My Powerwalls used to output 65 Hz during an outage. We contacted Tesla and they lowered the frequency so we no longer get the UPS alerts. They actually woke me up more than once.

We get the notifications from our power company as well but usually they are wrong or hours late.

The app doesn't have a feature to sound an alarm and when your phone goes in to DND mode the normal alert may not even do anything.

I have my Powerwall hooked up to my home automation system which activates an audible alarm when the grid goes out (among other things), I used a Zooz Z-wave chime. Amazon used to carry them through a 3rd party seller here in the US but I can only find Canada listings for it now.

 

[Owner]

Your pricing seems to be a bit off. See below table for Tesla pricing for California which include installation cost, permit fees, CA sales taxes at 9%, and credits. The actual price difference to go from one to two Powerwalls is only $4.9 K.

Okay, yes I did not include installation cost and permit fees. The marketing is very deceptive when you play around with the options it never mentions this! Not even in the fine print.

I had just assumed installation and permit fees were included.

Now I'm thinking of looking at a generator.

 

[nwdiver]

Now I'm thinking of looking at a generator.

So you can be one of these fools?

If you already have solar there are cheaper ways than a Powerwall. I AC coupled a Magnum Energy with 8 GC2s. Cost <$3k.

 

[MorrisonHiker]

The app doesn't have a feature to sound an alarm and when your phone goes in to DND mode the normal alert may not even do anything.

My Powerwalls send notifications whenever there is a grid outage of at least 5 minutes. Maybe you just need to turn yours on?

While this page is just for Backup mode, it applies for other modes as well: Backup-Only | Tesla Support

You can allow specified apps to still send notifications when in DND. You can also use Tasker or similar apps to perform actions so you could sound an alarm, etc. without any additional hardware.

 

[Owner]

If you already have solar there are cheaper ways than a Powerwall. I AC coupled a Magnum Energy with 8 GC2s. Cost <$3k.

I looked at that. Not a good solution. Inverter is at far end of the garage. Would have to snake power to refrigerator. Would be really difficult to use with multiple devices over a large house. Might be a good solution if you had say 1,000 square feet.

 

[nwdiver]

I looked at that. Not a good solution. Inverter is at far end of the garage. Would have to snake power to refrigerator. Would be really difficult to use with multiple devices over a large house. Might be a good solution if you had say 1,000 square feet.

You can put the off-grid inverter anywhere you have 240v. Doesn't have to be near the grid-tie. Just open the main and energize the off-grid. The best way to do this would be a dedicated 240v circuit that's only used for backup similar to how you would use a generator. This dedicated breaker would be interlocked with your main so it cannot be closed if the main is open.

 

[gpez]

My Powerwalls send notifications whenever there is a grid outage of at least 5 minutes. Maybe you just need to turn yours on?

While this page is just for Backup mode, it applies for other modes as well: Backup-Only | Tesla Support

View attachment 543149

You can allow specified apps to still send notifications when in DND. You can also use Tasker or similar apps to perform actions so you could sound an alarm, etc. without any addition hardware.

Was talking specifically about an alarm, I do get the outage notifications on the app. The Tasker suggestion is great. Notifications by themselves (with DND off) don't wake me.

 

[Owner]

Your pricing seems to be a bit off.

If you have roof space, consider keeping your existing system and augmenting with a separate one. That is what I did. I initially have 5.8 kW of solar. Later added two Powerwalls in 2017. And recently added 3.8 kW of solar (small) with Tesla. The Tesla energy gateway is able to control the output of the older mirco-inverters and the new inverter.

Did you make this table yourself?

What could be interesting is *if they can* add a small solar and 1 powerwall. That might be worth spending more money if I can keep the old solar working with it together.

Or compare to the price of a generator....

 

[GenSao]

Okay, yes I did not include installation cost and permit fees. The marketing is very deceptive when you play around with the options it never mentions this! Not even in the fine print.

I had just assumed installation and permit fees were included.

Now I'm thinking of looking at a generator.

The fine print is hard to see. The added fees apply for installation of Powerwalls alone. See the note on the PowerWall main page:

When Powerwalls are paired with the installing solar panels or solar glass roof, then the permit fees and taxes are covered by the other activity. The Powerwall Installation cost ($2,500) is offset by the is a combo package discount ($2,600). See below screen capture assuming a 7.56 kW (medium) system with two Powerwalls.

If going with a generator, do consider that it is a sunk cost that will require maintenance and fuel. The cost goes up dramatically if you want to replicate what the Powerwall does. The Federal Tax Credit and rate arbitrage for Time of Use rates can help soften the cost of the Powerwall.

Here is a generator to consider:
Generac Power Systems - 13kW Guardian Series Home Generator with Transfer Switch - 7174

Note, taxes, permits, and installation are excluded. You would want to pipe in natural gas to the generator to make things easier.

 

[GenSao]

Did you make this table yourself?

What could be interesting is *if they can* add a small solar and 1 powerwall. That might be worth spending more money if I can keep the old solar working with it together.

Or compare to the price of a generator....

Yes. I made the table myself and occasionally update as needed. Powerwall only pricing is accurate as I checked it to user posts on TMC.

If you have the roof space, then it is possible for a small solar (3.78 kW) and 1 Powerwall to augment your exisitng system. Do note, per the Tesla FAQ/support page: "Since Powerwall 2 is an AC coupled solution, it is compatible with all inverter types. To ensure reliable operation during power outages, at least one Powerwall is required for each 7.6 kW AC of solar included in the backup circuit."

Your existing 3.8 kW and the small solar 3.78 kW should fit within this requirement. The only thing I can not answer is if your inverter would be compatible with the Powerwall. I have non-smart, utility interactive, Enphase M-250 micro-inverters that responds to the Tesla energy gateway. Check the CA state list if your inverter is listed: Inverters

If not, perhaps the balanced approach is to have your old inverter replaced with a comparable one and add on afterwards.

 

[Owner]

Yes. I made the table myself and occasionally update as needed. Powerwall only pricing is accurate as I checked it to user posts on TMC.

This is very helpful. I'm now exploring the tiny solar and one powerwall option. Especially if it is an add on to my current solar.

 

[cali8484]

Did you make this table yourself?

What could be interesting is *if they can* add a small solar and 1 powerwall. That might be worth spending more money if I can keep the old solar working with it together.

Or compare to the price of a generator....

Generator is going to be much cheaper unless you get some big government incentives. One that meets your needs would be < $1K. However, you would be giving up all the green energy benefits (e.g. less pollution, quiet, etc.).

 

[nwdiver]

However, you would be giving up all the green energy benefits (e.g. less pollution, quiet, etc.).

Plus self-sufficiency, peace of mind and convenience;

 

[cali8484]

Plus self-sufficiency, peace of mind and convenience;

View attachment 543205

You can use natural gas and avoid all that.

 

[nwdiver]

You can use natural gas and avoid all that.

Unless there's an Earthquake... but those never happen in SF... right?

Plus we really need to move away from having fools fuel piped into our homes. In an area as temperate as CA that's beyond idiotic. Not sure paying ~$15/mo to have gas available on the rare occasion the grid is out makes any sense...

 

[MorrisonHiker]

Perfect, except I do have a Model S and have no plans on replacing it anytime soon. Hopefully not too far away for this feature to be added to the S.

does the app tell you that the grid is down?

PG&E sends alerts sometimes - yes sometimes.

My Powerwalls send notifications whenever there is a grid outage of at least 5 minutes. Maybe you just need to turn yours on?

While this page is just for Backup mode, it applies for other modes as well: Backup-Only | Tesla Support

View attachment 543149

You can allow specified apps to still send notifications when in DND. You can also use Tasker or similar apps to perform actions so you could sound an alarm, etc. without any additional hardware.

Last night, my power was out for over 3.5 hours. The Tesla app sent notifications when the grid went down and when the power was restored.

The power company sent a notification a couple of hours later to indicate things were working again. How timely.

 

[destructure00]

I have my Powerwall hooked up to my home automation system

Which HA system, and how? I have a Hubitat hub and currently in the permitting process for installing 2 PWs, in addition to expanding my 7.56kw subscription PV system to 11.34kw. Would love hook it all in to Hubitat.

 

[gpez]

Which HA system, and how? I have a Hubitat hub and currently in the permitting process for installing 2 PWs, in addition to expanding my 7.56kw subscription PV system to 11.34kw. Would love hook it all in to Hubitat.

I use Homeseer and wrote a plugin that interfaces directly with the Powerwall via the LAN.

 

[Owner]

You can use natural gas and avoid all that.

I would want a natural gas generator