Powerwall, Solar & Power Outage

[Hairyman]

So I’m having a little power outage in an Ausgrid NSW area.

My Powerwall 2 is pretty full (>80%) and keeping the lights, fridge and IT running.

However, as soon as the power went out the solar system switched itself off.

I wasn’t expecting this because I thought the Powerwall gateway would be wanting to supply the house and completely fill the battery before stopping generation.

I can understand that if I didn’t have the gateway the solar would go off as an anti-islanding measure for safety.

Is this just the way it is or have I got a configuration problem with either the gateway or the inverter.

Feel free to assume no prior knowledge and indeed ELI5 it.

Ta

 

[paulp]

So I’m having a little power outage in an Ausgrid NSW area.

My Powerwall 2 is pretty full (>80%) and keeping the lights, fridge and IT running.

However, as soon as the power went out the solar system switched itself off.

I wasn’t expecting this because I thought the Powerwall gateway would be wanting to supply the house and completely fill the battery before stopping generation.

I can understand that if I didn’t have the gateway the solar would go off as an anti-islanding measure for safety.

Is this just the way it is or have I got a configuration problem with either the gateway or the inverter.

Feel free to assume no prior knowledge and indeed ELI5 it.

Ta

Yes the solar should stay on. From tesla website:

Pair with solar and recharge with sunlight to keep your appliances running for days.

You have a config problem somewhere. When you call the useless liars from tesla powerwall usa, you’ll need to get past them somehow to get the attention of a usually very competent tesla australia tech. Maybe ask your installer to deal with it initially. They typically have direct contact to a local tech.

 

[Hairyman]

Yes the solar should stay on. From tesla website:

Pair with solar and recharge with sunlight to keep your appliances running for days.

You have a config problem somewhere. When you call the useless liars from tesla powerwall usa, you’ll need to get past them somehow to get the attention of a usually very competent tesla australia tech. Maybe ask your installer to deal with it initially. They typically have direct contact to a local tech.

Thanks. I’ll get on to it on Monday. For good or ill Tesla themselves did the installation so I’ll take a long game approach.

 

[Nobody Famous]

Is this the first power outage seen? Was it tested on installation?

Is it as simple as the Solar Inverter is connected on the grid side of the gateway?

Else, something related to the frequency the PW2 generates?

Grid outage - PowerWall not allowing solar production

I experienced a grid outage at 1:30 AM last night. Powerwall kicked in as expected. Current SOC is 71% and I would normally be producing solar at this point in the day. However, PowerWall is keeping the frequency at 62Hz Keeping the inverters offline. I called support and Tesla said this is...

teslamotorsclub.com

 

[Hairyman]

Thanks @Nobody Famous for the link.

It was tested on installation and is not the first outage - the others have happened at night and one first thing in the morning.

It has failed in this manner once before first thing in the morning with an almost empty battery.

I’ll be sure to include that in my discussions with Tesla.

 

[paulp]

Maybe the nearly empty battery is the issue? You could test that by turning off your supply with a low battery and doing the same with say half full battery, or half empty depending on how you see life.

 

[bcarp]

You haven't given enough information about whether this is expected behaviour or not. Has it charged from solar before? What you have described is expected behaviour in certain situations, such as my own system, which is limited to this for other reasons outside of the Powerwall's control.

Do you have single, 2 or 3 phase power? Do you have a single or three phase inverter? What kW panels do you have?

 

[Hairyman]

Thanks @bcarp.

I have three phase power. The PW backs up lights, fridges, and GPOs, but not air conditioning or the oven.

The PV system is 5.89kW of Sunpower 318 panels with a SMA Sunny Tripower 7kW three phase inverter.

I have had two events long enough for me to notice that the solar inverter turned off when the grid went down. One in the morning when the battery was almost flat (< 10%) and the solar generating less than 1kW. The house demand was about 1.5kW from memory. The inverter went off, the battery went flat, and then the house had no supply at all. The inverter stayed off until the grid came back up.

The other was yesterday when the battery was at 87%, the solar was generating 3.8kW. The house demand was 4.1 kW. The behaviour was the same.

I have had one 4 minute outage when I think the solar stayed on, but I’m not sure the PW data has the resolution to capture such a short event.

 

[paulp]

Thanks @bcarp.

I have three phase power. The PW backs up lights, fridges, and GPOs, but not air conditioning or the oven.

The PV system is 5.89kW of Sunpower 318 panels with a SMA Sunny Tripower 7kW three phase inverter.

I have had two events long enough for me to notice that the solar inverter turned off when the grid went down. One in the morning when the battery was almost flat (< 10%) and the solar generating less than 1kW. The house demand was about 1.5kW from memory. The inverter went off, the battery went flat, and then the house had no supply at all. The inverter stayed off until the grid came back up.

The other was yesterday when the battery was at 87%, the solar was generating 3.8kW. The house demand was 4.1 kW. The behaviour was the same.

I have had one 4 minute outage when I think the solar stayed on, but I’m not sure the PW data has the resolution to capture such a short event.

I have micro-invertors so a bit different to yours. Not sure if a 3 phase invertor can stay on when only one of its phases is backed up and seeing power, but maybe it can…not sure

 

[jjrandorin]

So I’m having a little power outage in an Ausgrid NSW area.

My Powerwall 2 is pretty full (>80%) and keeping the lights, fridge and IT running.

However, as soon as the power went out the solar system switched itself off.

I wasn’t expecting this because I thought the Powerwall gateway would be wanting to supply the house and completely fill the battery before stopping generation.

I can understand that if I didn’t have the gateway the solar would go off as an anti-islanding measure for safety.

Is this just the way it is or have I got a configuration problem with either the gateway or the inverter.

Feel free to assume no prior knowledge and indeed ELI5 it.

Ta

I am going to preface my comment that I am not very familar with international setups. Sometime recently, in the Tesla Energy subforum, we have noticed that there seems to have been some sort of change in when solar is allowed back on by the powerwall(s) when in an off grid situation.

I havent tested it on my own setup recently, but others have reported that solar was switched off by the powerwall (the way it normally does that, by changing power frequency) at a lower level than it used to. Previously for many of us, solar would be off from powerwall at 100% down to powerwall at around 90-92%, then come back on, but recently a few have reported similar experience as this OP.

OP when you hear something can you let us know what you heard in the tesla energy subforum?

 

[Hairyman]

I am going to preface my comment that I am not very familar with international setups. Sometime recently, in the Tesla Energy subforum, we have noticed that there seems to have been some sort of change in when solar is allowed back on by the powerwall(s) when in an off grid situation.

I havent tested it on my own setup recently, but others have reported that solar was switched off by the powerwall (the way it normally does that, by changing power frequency) at a lower level than it used to. Previously for many of us, solar would be off from powerwall at 100% down to powerwall at around 90-92%, then come back on, but recently a few have reported similar experience as this OP.

OP when you hear something can you let us know what you heard in the tesla energy subforum?

Thanks very much @jjrandorin. I’ll be sure to let you know

 

[atj777]

a SMA Sunny Tripower 7kW three phase inverter.

I think this may be your problem. I think the Gateway is limited to 5kW (or thereabouts). When you have grid power it is OK because it moves things about so it looks like you are using your own power but are actually putting out to the grid and getting from the grid at the same time.

When the grid goes out, the 7kW is too much and the solar is disconnected.

That is the case for my system with a 10kW inverter.

 

[Hairyman]

I think this may be your problem. I think the Gateway is limited to 5kW (or thereabouts). When you have grid power it is OK because it moves things about so it looks like you are using your own power but are actually putting out to the grid and getting from the grid at the same time.

When the grid goes out, the 7kW is too much and the solar is disconnected.

That is the case for my system with a 10kW inverter.

Thanks @atj777. I’ll mention that in my chat with the Tesla crew. If I have no joy there I will have a talk to my solar installers who also now sell Powerwalls and see if they have some insight.

 

[atj777]

I was told that if I replace the 10kW inverter with 2 x 5kW inverters (which I can do as I have two PV arrays), one of the inverters could be rigged up to provide solar in a grid outage.

 

[bcarp]

Your problem is indeed three-phase solar inverter. Your Powerwall is a single phase device, as is its gateway. You cannot have a three-phase solar inverter charging the without the grid active. If you go across to the Whirlpool forums and look at the PowerWall topic, This has been discussed at length and there would be at least 50 posts on this topic and why it is the case. It is beyond my basic electrical understanding except that it is not possible. I have a similar set up to you and while this is a disadvantage of the three-phase solar inverter, the advantage is that you can send to the grid beyond the 5 kW feed in limit of a single phase inverter.

 

[Hairyman]

Your problem is indeed three-phase solar inverter. Your Powerwall is a single phase device, as is its gateway. You cannot have a three-phase solar inverter charging the without the grid active. If you go across to the Whirlpool forums and look at the PowerWall topic, This has been discussed at length and there would be at least 50 posts on this topic and why it is the case. It is beyond my basic electrical understanding except that it is not possible. I have a similar set up to you and while this is a disadvantage of the three-phase solar inverter, the advantage is that you can send to the grid beyond the 5 kW feed in limit of a single phase inverter.

Thanks very much indeed @bcarp . That being the case I will not pester Tesla or my installer. My inverter is getting on for 7 years old so when it comes time to replace it I’ll see what can be done to manage this. Cheers

 

[evpaddie]

I was told that if I replace the 10kW inverter with 2 x 5kW inverters (which I can do as I have two PV arrays), one of the inverters could be rigged up to provide solar in a grid outage.

This works for us. We have 2 phase power, two arrays of panels (5kw and 6kw) and two inverters. The 6kw array was installed with PW and the new second inverter. In an outage, our PW and 6kw array continue to supply power to the house and the 6kw array tops up PW with excess solar power.

 

[atj777]

This works for us. We have 2 phase power, two arrays of panels (5kw and 6kw) and two inverters. The 6kw array was installed with PW and the new second inverter. In an outage, our PW and 6kw array continue to supply power to the house and the 6kw array tops up PW with excess solar power.

And two Powerwalls? I assume you mean 5kW for one of the arrays in a power outage.

 

[evpaddie]

And two Powerwalls? I assume you mean 5kW for one of the arrays in a power outage.

The 6kw array and its Fronius inverter are the only working array in an outage. If maximum it can supply is 5kw, I've never checked, than that is what it is doing.

 

[Stratman]

In our setup when grid goes down, the two inverters remain on charging the PW'2s until they reach 97%. at this point the gateway / PW2's throttle the inverters to meet the household load. If the house load is too small the inverters are then shut down. I have single phase setup with all house ccts backed up on gateway.