Generic question regarding Wattage

Discussion about adding energy storage to grid-dependent inverters using OutBack Power technology
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trevinom
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Generic question regarding Wattage

Post by trevinom »

I have a SolarEdge 10k inverter that is being powered by 9.8k of solar panels.
This particular inverter does not support battery backup, so trying to AC-Couple it to a hybrid inverter.
My question is, can I hook up a lower rated wattage hybrid inverter to drive a higher wattage grid-tied inverter?
I was thinking of using your OUTBACK RADIAN GS8048A 8KW as the hybrid inverter to do this but not sure if it can be hooked up to my 10k SolarEdge Inverter.
pss
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Re: Generic question regarding Wattage

Post by pss »

Your question is rather confusing.

In an Outback system environment, the solar panels are connected to charge controllers and these are connected to the battery bank. The battery bank is connected to the inverter. Once powered, the inverter can be AC coupled to PV panels with microinverters on them. The output from an Outback inverter is to an AC load. If you want to output the AC load of the Outback into a "grid tie" or AC input connection on your existing inverter and then have that be used when your Solar Edge goes out, it could be done, but might not be reliable. You would still need batteries to power up the Outback and you would still need a Mate 3S and an Outback hub.

The correct solution to your problem is to jettison your Solar Edge inverter and install an Outback Radian inverter, charge controller, Mate 3S and hub. Then your system will work the way you want it to work.
raysun
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My RE system: Flexpower Two: (2) FXR3048A-01 - Parallel Stacked, (2) FM80, MATE3s, FlexNetDC
6 SimpliPhi 3.8-48 (48v @ 75AH. 450AH total)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
2 Midnite Solar MNPV6 combiners w/20A DC disconnects.
Honda EU7000is gas fuel generator
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Re: Generic question regarding Wattage

Post by raysun »

Outback's white papers on AC Coupling:
https://www.outbackpower.com/applications/ac-coupling

The AC Coupling design guide states the Radian is limited to 6kW of grid tie inverter output.

When AC coupled PV is used to charge the Radian's battery, the grid tie inverter must be compliant with output limiting by frequency shifting as controlled by the Radian. The papers detail that function.
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Mike Curran
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My RE system: Outback - Garage roof (2007/2017):
- 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

Battery systems operate in grid-tied, net metering w/backup mode
All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Generic question regarding Wattage

Post by Mike Curran »

Fyi, both Outback's Skybox and Mojave inverters can AC couple up to 7.6kva from a grid dependent inverter. I would call Outback Sales for their opinion. 360.435.6030
https://ei.tigoenergy.com/p/pZXn7SZQyO45
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
trevinom
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Re: Generic question regarding Wattage

Post by trevinom »

raysun wrote: Tue Nov 22, 2022 9:43 am Outback's white papers on AC Coupling:
https://www.outbackpower.com/applications/ac-coupling

The AC Coupling design guide states the Radian is limited to 6kW of grid tie inverter output.

When AC coupled PV is used to charge the Radian's battery, the grid tie inverter must be compliant with output limiting by frequency shifting as controlled by the Radian. The papers detail that function.
Thank you for the link, raysun.
In looking at this pdf: https://www.outbackpower.com/downloads/ ... p_note.pdf
I was trying to describe the scenario on page 2 titled "Figure 2 GTI Power Flow with Active PV"
I'm assuming the red box is my SolarEdge inverter which would be connected directly to my emergency panel.
This means, that i'm not connecting it directly into the Radian inverter and would think that the wattage my SolarEdge system puts out can be more than what the Radian inverter is rated for, since my emergency panel will be pulling some of that wattage.
I'm trying to minimize my expenses while adding battery backup to my solar system so I want to continue using the SolarEdge system. The AC-Coupling would call on the Radian inverter to send out a 60Hz signal that would allow the SolarEdge system to continue producing power in case of an outage and I can add a battery bank to the Radian.
Does this sound reasonable?
raysun
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Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
2 Midnite Solar MNPV6 combiners w/20A DC disconnects.
Honda EU7000is gas fuel generator
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Re: Generic question regarding Wattage

Post by raysun »

I'm afraid I'm strictly off-grid so my grid-tie/AC coupling knowledge is white paper thin. Mike's suggestion of placing a call to Outback Sales is a good one. I've found the folks on the other end of the line to be helpful, knowledgeable, and readily available. You'll get the lowdown without any sales pitch.
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Mike Curran
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Posts: 2912
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof (2007/2017):
- 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

Battery systems operate in grid-tied, net metering w/backup mode
All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Generic question regarding Wattage

Post by Mike Curran »

trevinom wrote: Tue Nov 22, 2022 7:32 pm In looking at this pdf: https://www.outbackpower.com/downloads/ ... p_note.pdf
I was trying to describe the scenario on page 2 titled "Figure 2 GTI Power Flow with Active PV"
I'm assuming the red box is my SolarEdge inverter which would be connected directly to my emergency panel.
This means, that i'm not connecting it directly into the Radian inverter ....Does this sound reasonable?
Yes, the red box is your SolarEdge. But connected to your backup panel is the same place the output of the Radian is connected. That's how your SolarEdge gets the 60Hz signal to make it think the grid is still "up", and how your backup panel gets battery support (via Radian) during an outage.

Your point about the backup panel loads absorbing some of the SolarEdge output and thus reducing what remains to be sold through the Radian is a good one. But I don't know what happens if more than 6kw tries to pass through the Radian to be sold. Perhaps it simply passes only 6kw and throttles your SolarEdge (using frequency/watt control) to limit pass through anything over that. A call to Outback might help answer this.
https://ei.tigoenergy.com/p/pZXn7SZQyO45
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
Ampster
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Location: Kenwood, Northern California

Re: Generic question regarding Wattage

Post by Ampster »

Mike Curran wrote: Wed Nov 23, 2022 5:56 am..........

Your point about the backup panel loads absorbing some of the SolarEdge output and thus reducing what remains to be sold through the Radian is a good one. But I don't know what happens if more than 6kw tries to pass through the Radian to be sold. Perhaps it simply passes only 6kw and throttles your SolarEdge (using frequency/watt control) to limit pass through anything over that. A call to Outback might help answer this.
When the grid is up the Radian cannot frequency shift because the grid 60 Hz signal passes through to the SolarEdge. I have a similar situation with my Skybox and cannot control the GT inverters with the Skybox when the grid is up. Hopefully that is the same answer Outback provided. There are other options which I will be trying when I add more panels than my NEM agreement allows and if interested I would be happy to elaborate.
Use my Skybox in Self Consumption mode to reduce my energy costs, including charging two EV from solar when possible.
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Mike Curran
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Posts: 2912
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof (2007/2017):
- 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

Battery systems operate in grid-tied, net metering w/backup mode
All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Generic question regarding Wattage

Post by Mike Curran »

Ampster wrote: Tue Nov 29, 2022 1:51 pmWhen the grid is up the Radian cannot frequency shift because the grid 60 Hz signal passes through to the SolarEdge.
D'oh! Thanks.
https://ei.tigoenergy.com/p/pZXn7SZQyO45
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
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