Hawaiian Electric forcing export of our solar?

[Gu$ G]

Can anyone help me diagnose why I'm occasionally catching energy exported to the grid mid-day even when I have plenty of capacity on my 6 PWs?

On Friday my system generated 69.6 kWh and expired 26 kWh. I estimate I lost over 20 kWh that should have gone to the batteries. Energy production was around 6-9 kW, home consumption 1-2 kW, and only 1-2 kW was going to the batteries. The rest was going into the grid.

I'm making this assessment based on the real time observation of flow in the app. It's also supported by the summary data as I look back over the last week.

Kailua, HI; 48 panel Tesla install, 6 PWs, 1-2 year old equipment

We have a few friends that live in our town who have noticed the same problem. An on island solar installer told their customers the problem was not Tesla or their equipment but with Hawaiian Electric (HECO). They called it "compliance." Whatever that means.

We are on CGS Plus as our rate plan. I imagine there are caveats for them to pull energy in emergencies but it's hard to imagine a reason this would have happened on multiple days, on and off, over the last week. We certainly weren't notified.

 

[Gu$ G]

First image shows normal behavior, the PW is full and solar begins exporting to the grid. In this case, that happened around 11am. No issue here.

Here you see a summary of what I saw Friday. The batteries were charging slowly, excess was going to the grid.

Finally, here's the same day's PW capacity showing nearly empty and not really charging.

 

[n.one.one]

Can anyone help me diagnose why I'm occasionally catching energy exported to the grid mid-day even when I have plenty of capacity on my 6 PWs? ...........................................................................................................................
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Is there any possibility that the Tesla app is calculating a financial advantage to exporting?

• Is the utility paying you for the power you export?
• What are your Tesla app settings for buying from, and selling to the utility?
• Are you on a time of use plan with the utility?

 

[sunwarriors]

I'm not from Hawaii, but did you get your batteries through any Hawaiian Electric incentive (discount) program?

 

[Gu$ G]

Thanks for the replies. Two points I left out.

1. I doubt it. If so, it's a mistake. We do not subscribe to TOU. Our rate plan pays 7c per kwh exported and charges about 40c per kWh imported.

Never the less, I changed the sell prices in the app to $0. I also have "self-powered" selected and do not charge from the grid.

2. I am not yet participating in the battery bonus program offered by HECO. Additionally, the undesired export seems to be happening mid day, around noon.

Emphasize again this is not just excess solar exceeding the batteries charge rate. I'm only charging PW at 1-3 kW when this happens.

I have another friend from a different part of our island that checked his app on Friday. He says his system pulled from his batteries and exported 4.2 kWh, which is very high. He often sees 1-2 exported on a given day as more normal. He has far less solar generation and only 2 PW.

 

[jjrandorin]

Perhaps I missed it, but are you using self powered mode or time of use? Time of use mode can choose to export power based on buy and sell price differences, etc. Self powered doesnt do any of that.

 

[Gu$ G]

Perhaps I missed it, but are you using self powered mode or time of use? Time of use mode can choose to export power based on buy and sell price differences, etc. Self powered doesnt do any of that.

Self powered. We are not enrolled in a time of use program. It is always better for us to store energy vice send to the grid. The credit value is much lower than the cost to use, at all times.

 

[Gu$ G]

Another update. Over the past week this problem has not reoccurred. Every day since noting this problem I export no more than about 0.3 kWh to the grid. The days I've noted above remain anomalies with no validated explanation.

I called HECO. The person on the phone claimed this was a problem with Tesla. They said the Tesla system falsely flagged a grid requirement for solar export to grid for some customers. I'm not sure where they got this idea / info from. I'm not sure I believe it. She referenced having gotten this information from HECO technical support team.

 

[Papafox]

@Gu$ G
I had the same problem happen with Hawaiian Electric. I was talking to Tesla Energy about it and they implied that something related to the utility was going on but they wouldn't elaborate.

Today we have an outage in Kailua and my solar has been producing zero throughout the day. Tesla has elevated the problem but they claim it may be 5 days before someone gets back to me. Ugh. It just might be a glitch in my system, but if someone else on Hawaiian Electric is having the same issue it would be very eye opening, to say the least.