How is this "self consumption"?

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Mike Curran
Forum Emperor
Posts: 2123
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

All self-designed and self-installed
Location: Chagrin Falls, Ohio

How is this "self consumption"?

Post by Mike Curran »

Attached is a short video (37 seconds) showing my Skybox web interface this morning. Skybox is set up in self-consumption mode, which the manual describes as follows:
Screenshot_20210115-104644.jpg
If I'm interpreting this correctly, I shouldn't be buying from grid when there's PV and battery power available. But the video shows Skybox shifting between buying, selling, and zeroing pretty much constantly. Meanwhile the battery is alternating between charging and resting, and the load tile indicates the load is being fed 300 watts when in fact my load is miniscule and I'm actually AC-coupling 300 watts from my AC array (at least the color green has it right - if my loads were actually being fed 300 watts the load icon would be colored yellow).

Any thoughts on what's going on? You folks with grid zero setups might have some insight on this behavior, so thanks for any input.
https://youtu.be/Qp0W89VL6qk
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
Mike Curran
Forum Emperor
Posts: 2123
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: How is this "self consumption"?

Post by Mike Curran »

It looks like I was wrong about the load tile coloring :oops: . Here it's shown as AC-coupling in yellow:
Screenshot_20210115-112821_Samsung Internet.jpg
I would've sworn it was AC-coupling when the video was made. Still, why am I buying in self consumption mode?
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
User avatar
Kim Foster
Systems Engineering
Posts: 20
Joined: Tue Jan 09, 2018 12:16 pm

Re: How is this "self consumption"?

Post by Kim Foster »

Looks like your system is mostly behaving. The back and forth between buying and selling is seen when the loads are low in self-consumption and non-export. This is because the SkyBox is trying to balance three different sources of power simultaneously and we've needed to increase the speed due to some new California protocols. This can result in some "sloshing" at low loads. If you increased the loads a bit you should see it stabilize.

With respect to the color of the tile, they do sometimes update slower than they should. If you see a value that looks suspicious, double-check by navigating into the tile itself and page down once past the graph. These values are more accurate when the donuts appear incorrect. Negative load indicates power flowing into the SkyBox, positive load is the opposite. The same convention is true with the grid power (negative = in and positive = out).
Kim Foster
Systems Engineering
Mike Curran
Forum Emperor
Posts: 2123
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: How is this "self consumption"?

Post by Mike Curran »

Thanks!!!!
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
Ampster
Forum Guru
Posts: 159
Joined: Sat Apr 11, 2015 5:14 pm
My RE system: 5.7K solar system with Solaredge inverter. Heat pump water heater.
28 kWh pack of LFP batteries powering a Skybox which is used for load shifting and backup.
Location: Sonoma, Northern California

Re: How is this "self consumption"?

Post by Ampster »

I have used self consumption a lot and noticed the same thing. Kim Fosters explanation made sense to me from my observations.
Drive Tesla Model X and Model 3 which are charged at Super Off Peak rates.
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