Weird, my home experienced a brief energy dip; neighbors were not affected

[holeydonut]

So I just had a weird experience... about an hour ago (6:45pm Pacific) we were cooking dinner and doing some chores. The Emporia Vue showed a modest 5kW of home loads at that time.

But then a few of our lights dimmed in the kitchen; the vent-hood fan slowed down then sped up. I went to my phone to check the Tesla app. Sure enough, it indicated a 17 second power outage.

The weird part is I asked one next door neighbor if he had a service interruption, and he said no. He has a Ting energy monitor and it recorded no anomalies. The neighbor across the street and to my other side didn't experience anything either. None of these homes have any ESS.

So basically, my house was the only one that saw the mini blip... which leads me to believe it's related to my installed components and energy coming from the Powerwalls. (3x Powerwalls with a SoC of ~70%)

Is there a way I can pull reporting on the frequency/voltage of the PoCo or my Powerwalls at the time of the alleged "power outage?" It would be great if the Gateway had this information stored since it's the brains of everything. Sunset today was 6:04 PM; so this is not related to my PV.

The part that confuses me is that my house has basically been "off grid" of sorts for the last 14 days. I haven't taken more than 0.1 kW power from PG&E; and I've sent 0.0 back to them since I don't have PTO. The daily solar production has been able to offset all my demand on a daily cycle. Basically, PG&E going offline shouldn't have done anything anyway; I've been 100% self powered for 14 days.

Is this common? That is... once you get Powerwalls you experience more frequent mini blips due to the extra tech?

 

[bob_p]

Yes.

In the Houston area, we periodically will have very brief power interruptions.

Even if the power is disrupted for a very brief time (short enough just to cause the lights to flicker), the TEG switches to off grid operation - and waits 5 minutes before it attempts to reconnect.

When this happens, I'll look at the nearby houses to see if they still have power (water fountain or pool pumps running is an easy check) - and almost all of the time, they are still running, even though we're operating off the PowerWalls.

This is actually a good thing - it's like running a system check every few weeks to verify the TEG can run off grid...

 

[zƬesla]

What @bob_p said. A few months back I kept noticing several 5-minute "grid out" occurrences. Neighbors typically noticed just a brief dim-light effect as the grid fluctuated, but in our case the TEG took us offline longer.

 

[Electrph]

@bob_p sounds like reasonable explanation if you were on grid power at time, however if I read correctly you were already completely on battery power ? I don’t believe you should have seen any interruption if grid power were even momentarily interrupted

 

[wjgjr]

I feel like this goes beyond the question of how the system responds to an anomaly and to the question of whether @holeydonut experienced an anomaly actually caused by the system, since he is suggesting there was an event at his house, but his neighbor's equipment detected no issues.

Out of curiosity, was this event directly linked to starting the microwave or an electric stove/oven (since you said it was dinner time.) Before getting PTO, operating off-grid, the only strange behavior I saw was the solar stopping a couple of times, and it seemed to correlate with a spike in usage - namely the microwave. It was not a consistent thing, and we were never close to 10 kWh usage, but it seemed that was a potential trigger. That said, on grid, it has not once been an issue.

 

[holeydonut]

I feel like this goes beyond the question of how the system responds to an anomaly and to the question of whether @holeydonut experienced an anomaly actually caused by the system, since he is suggesting there was an event at his house, but his neighbor's equipment detected no issues.

Out of curiosity, was this event directly linked to starting the microwave or an electric stove/oven (since you said it was dinner time.) Before getting PTO, operating off-grid, the only strange behavior I saw was the solar stopping a couple of times, and it seemed to correlate with a spike in usage - namely the microwave. It was not a consistent thing, and we were never close to 10 kWh usage, but it seemed that was a potential trigger. That said, on grid, it has not once been an issue.

I wasn’t using more loads than I had been over the last two weeks... and the dimming wasn’t initiated by a large appliance or air conditioner turning on.

And yes, I wasn’t exposed to the grid at the time since my home was being powered only by the Powerwalls already. I’ve actually tested my system before by flipping the giant blade disconnect to cut off my PoCo power and my wife said the lights stayed on fine inside.

I just hope this is a one off weird event. My wife was super annoyed since she thinks Sunrun may have messed something up. I’m trying to find a reasonable explanation to things. And she’s already super pissed about terrible this install has gone. Plus PG&E is threatening to deny my SGIP rebate, so that’s another $8,700 I’m not getting back as a crappy surprise.

 

[gpez]

I wasn’t using more loads than I had been over the last two weeks... and the dimming wasn’t initiated by a large appliance or air conditioner turning on.

And yes, I wasn’t exposed to the grid at the time since my home was being powered only by the Powerwalls already. I’ve actually tested my system before by flipping the giant blade disconnect to cut off my PoCo power and my wife said the lights stayed on fine inside.

I just hope this is a one off weird event. My wife was super annoyed since she thinks Sunrun may have messed something up. I’m trying to find a reasonable explanation to things. And she’s already super pissed about terrible this install has gone. Plus PG&E is threatening to deny my SGIP rebate, so that’s another $8,700 I’m not getting back as a crappy surprise.

I took a look at the Ting monitor and it seems it would have detected something, I'd double check on that.

Ignoring the lack of confirmation from your neighbor with the Ting monitor I would have guessed that there was a momentary utility voltage drop, your Powerwall detected it and kicked in briefly, the utility voltage returned to normal and the Powerwall disengaged. If you were not already on the Powerwall (ie backup) that transition could manifest itself as a blip and the motor speed up in your vent hood could be due to the local grid frequency increasing when your Powerwall is full.

Anecdotally I've noticed this exact behavior where a small, brief utility power blip freaks the Powerwall out momentarily but neighbors didn't notice. The reverse has happened to me as well where neighbors will ask if there was a power blip and I didn't notice but the Powerwall had it logged. IMO someone noticing a power blip is a combination of: 1) how much someone is paying attention (are you staring at the lights or distracted doing something else?), 2) how severe the blip is (a small flicker is much harder to notice than the power going fully out then coming back), 3) what electrical items were in use at the time (lights flicker easily, microwave and vent hood motors change sounds, clocks and computers reset, etc).

 

[Electrph]

question for you @holeydonut .. have you tried going truly off grid (shut off utility )
reason i ask is on my system (two pw / pv)
when off grid, utility breaker off ..(and this is not behavior when pw near capacity) ac freq behaves diff ..
i watched on a monitor it jumps constantly from about max of 60.08 hz to 59.92.when i switch on utility power even though i am completely on battery i read a rock steady 60.01hz
point being when truly off grid my microwave starts up sounding different .. my fridge has slightly diff pitch and most notable some of my led lights when set dim flicker enough to annoy crap out of my gf
could this be what you experienced for that time interval ? the lack of utility power stabilizing the hz ?

 

[gpez]

@holeydonut another thought is you can query the TEG api for the last error or call Tesla and ask support to pull the logs. The error codes I've seen on my TEG are super unhelpful but I've found that Tesla support has access to more detailed information which they've shared with me to explain outage behavior. Perhaps a short call to them can shed some light on what your Powerwall saw at least.

 

[jboy210]

I am in the "you had a momentary drop in voltage and/or current" camp. We have had several of these and each time the TEG switched to the Powerwalls for around 20 seconds even though the drop was over in a second to two. I assume the TEG has a minimum time between switching to batteries and switching back to the grid.

Depending upon how your neighborhood was wired your neighbor may not notice anything. Our home and the one next door were the models for our little neighborhood. We are on a separate transformer from the people across the street and on one side. When they recently did a transformer replacement, 30 of the 40ish homes were out for 8 hours. The other 10 were only out for two 10 minute periods because of how the grid is wired.

 

[holeydonut]

Thanks @Electrph, @gpez, and @jboy210 !

It does seem plausible that just having PG&E operational (but not actually pushing energy into my home) helps to stabilize things. But then when the TEG detected something out of bounds it flipped its internal relay to block PG&E which resulted in a momentary lapse/change in the behavior of some lights and equipment in my home.

I need to look into querying the API. I'm a finance-loser; not a programming-geek. I haven't even figured out yet how to log in as an installer to the TEG2 hah.

Anyway, I guess I need to convince the wife that the system is behaving as intended and the "blip" was just because the Tesla system wanted to distance itself from PG&E for a few seconds.

 

[MorrisonHiker]

I am in the "you had a momentary drop in voltage and/or current" camp. We have had several of these and each time the TEG switched to the Powerwalls for around 20 seconds even though the drop was over in a second to two. I assume the TEG has a minimum time between switching to batteries and switching back to the grid.

Depending upon how your neighborhood was wired your neighbor may not notice anything. Our home and the one next door were the models for our little neighborhood. We are on a separate transformer from the people across the street and on one side. When they recently did a transformer replacement, 30 of the 40ish homes were out for 8 hours. The other 10 were only out for two 10 minute periods because of how the grid is wired.

We had 860 of those 5 minutes "outages" last summer. I know the neighbors knew there were issues with their power but I doubt they noticed over 800 of them. lol. At least one neighbor has signed up for solar with a Powerwall and another neighbor is considering solar.

We're hoping our new transformer prevents all those "outages" this year.

 

[jboy210]

We had 860 of those 5 minutes "outages" last summer. I know the neighbors knew there were issues with their power but I doubt they noticed over 800 of them. lol. At least one neighbor has signed up for solar with a Powerwall and another neighbor is considering solar.

We're hoping our new transformer prevents all those "outages" this year.

So are you saying your transformer issues were due to it being summer?

 

[jboy210]

Thanks @Electrph, @gpez, and @jboy210 !

It does seem plausible that just having PG&E operational (but not actually pushing energy into my home) helps to stabilize things. But then when the TEG detected something out of bounds it flipped its internal relay to block PG&E which resulted in a momentary lapse/change in the behavior of some lights and equipment in my home.

I need to look into querying the API. I'm a finance-loser; not a programming-geek. I haven't even figured out yet how to log in as an installer to the TEG2 hah.

Anyway, I guess I need to convince the wife that the system is behaving as intended and the "blip" was just because the Tesla system wanted to distance itself from PG&E for a few seconds.

You could just point out that we all should want to distance ourselves from PG&E.

 

[MorrisonHiker]

So are you saying your transformer issues were due to it being summer?

Yeah, I think it was a combination of temperature/direct sunlight on the transformer and the load used by our neighbors on the shared transformer. We only had the problem on hot days from May - October 9th last year. We figured it was our neighbor's A/C and pool pump that were causing the issue. Our utility company finally installed a new transformer in November and we've only had 2 outages since then, both during snowstorms.

 

[zƬesla]

When they recently did a transformer replacement, 30 of the 40ish homes were out for 8 hours.

Wow! We had no downtime when ours was switched out for a larger one to support our PV/PW install last year.

 

[jboy210]

Wow! We had no downtime when ours was switched out for a larger one to support our PV/PW install last year.

They had to replace the transformer and the underground vault which was leaking. They had a lot of equipment (crane, backhoe, paver, etc.) down at the end of the street. Great fun for the neighborhood kids who were watching instead of doing school on Zoom.

 

[jboy210]

Wow! We had no downtime when ours was switched out for a larger one to support our PV/PW install last year.

We had no downtime either, thanks to the Powerwalls!

 

[MorrisonHiker]

We had no downtime either, thanks to the Powerwalls!

No downtime for use either as our Powerwalls kept everything running on both days of our transformer install. They only cut power for a little over an hour each time.

One thing I forgot to mention is that we reported the problem in May 2020. Xcel came out and dug holes for new poles. They had actually replaced nearly every pole in my small town except for the poles on my block. In June, a derecho knocked down all the old poles in my neighborhood except the 3 leading to my house. Xcel replaced all the downed poles about 48 hours later but they didn't come back until 5 months later to replace the last three poles and install a new transformer.