Everything Solar Forum

I was led to believe that if I had a power outage with my co-op provider that I could flip a switch and enjoy power generated from my system as long as it was sunny.

This turned out to be false.

I have read that a “special inverter” exists that would allow this.

Has anyone heard of this? If so, how much $$ for installation?

Please advise and thanks!

JC

Sent from my iPhone

The only inverter that I know of that meets that description is the Enphase IQ-8 MICROINVERTER. Since its a "micro" it requires one under each panel - and it's not "backwards compatible" with anything else....

If the sun shines and the power is down, it will provide as much power as you have solar (minus losses, of course...) but if you exceed what the sun and the microinverters are doing, it will SHUT DOWN, until you reduce the load to what the system is capable of...

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Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
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Since your existing array shuts off during a grid outage to prevent back-feeding the grid and creating a hazard for linemen, you will need batteries and an AC-coupled battery-based inverter to use the energy from your grid-tied array when the grid is down.  These are nothing "special", they simple provide an AC output for your existing array to "see" and think the grid is still up, when it's not.  In these type systems the grid is connected through the new battery-based inverter - grid is still disconnected in an outage, but the battery DC power is inverted to AC to provide power to your house loads.  Your array will still charge the battery as well, although in this arrangement special considerations (the new inverter must have AC-coupling in its skillset) must be made to prevent battery overcharging.  Much more complex than the grid-tied system (I assume) you have now.

Edit:  With battery backup as described above, your system will provide power day or night.  
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Mike Curran
Retired from (dare I say it?) Fossil Plant Mgt.
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Or you can switch to ENPHASE IQ-8 Microinverters. One under each panel. When the utility goes out, they WILL PROVIDE 240vac/split to your home if the sun is out. More sun means more power. If you use more power than they can make, they shut down until you reduce the load, then they come back on. When the sun goes down you have NO POWER.

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Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
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Original Message:
Sent: 01-12-2023 10:57 AM
From: Mike Curran
Subject: Inverters that allow use of power when provider is down?

Since your existing array shuts off during a grid outage to prevent back-feeding the grid and creating a hazard for linemen, you will need batteries and an AC-coupled battery-based inverter to use the energy from your grid-tied array when the grid is down.  These are nothing "special", they simple provide an AC output for your existing array to "see" and think the grid is still up, when it's not.  In these type systems the grid is connected through the new battery-based inverter - grid is still disconnected in an outage, but the battery DC power is inverted to AC to provide power to your house loads.  Your array will still charge the battery as well, although in this arrangement special considerations (the new inverter must have AC-coupling in its skillset) must be made to prevent battery overcharging.  Much more complex than the grid-tied system (I assume) you have now.

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Mike Curran
Retired from (dare I say it?) Fossil Plant Mgt.
------------------------------

The SMA Sunny Boy inverters had a feature called Secure Power Supply that provides one outlet with up to 2000 Watts when the grid is down.  The inverter shuts down in an outage, but when you flip the switch it is isolated from the grid and any power coming from the solar panels (up to 2000 W) is available at the standby outlet.  I have a Sunny Boy 7.7-US installed in 2016 that has this feature.  I have tested it with the inverter disconnected from the grid, I plugged my refrigerator and some lights into the standby outlet and it worked fine.  I just did a search on the web and found several places advertising SMA inverters with this feature but could not find it mentioned at the SMA website.  It seemed like a great feature for resilience so I would hate to think they have discontinued it.  I feel like I could survive a long outage, even if we could not get gasoline for a generator, by running the refrigerator and charging my devices and batteries while the sun was shining.

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James Byrd
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Original Message:
Sent: 01-12-2023 03:03 PM
From: Joe Utasi
Subject: Inverters that allow use of power when provider is down?

Or you can switch to ENPHASE IQ-8 Microinverters. One under each panel. When the utility goes out, they WILL PROVIDE 240vac/split to your home if the sun is out. More sun means more power. If you use more power than they can make, they shut down until you reduce the load, then they come back on. When the sun goes down you have NO POWER.

------------------------------
Joe Utasi
PV Solar Consultant
Cinci Home Solar, Keowee Home Solar, DIY Solar Helper
------------------------------


Original Message:
Sent: 01-12-2023 10:57 AM
From: Mike Curran
Subject: Inverters that allow use of power when provider is down?

Since your existing array shuts off during a grid outage to prevent back-feeding the grid and creating a hazard for linemen, you will need batteries and an AC-coupled battery-based inverter to use the energy from your grid-tied array when the grid is down.  These are nothing "special", they simple provide an AC output for your existing array to "see" and think the grid is still up, when it's not.  In these type systems the grid is connected through the new battery-based inverter - grid is still disconnected in an outage, but the battery DC power is inverted to AC to provide power to your house loads.  Your array will still charge the battery as well, although in this arrangement special considerations (the new inverter must have AC-coupling in its skillset) must be made to prevent battery overcharging.  Much more complex than the grid-tied system (I assume) you have now.

------------------------------
Mike Curran
Retired from (dare I say it?) Fossil Plant Mgt.

Jeffrey,
   Sorry to hear that you received false information.  The SMA TL series inverters allow the homeowner to close a switch during grid failure, to energize a separate circuit with a limited amount of power, while the photovoltaic array in receiving sunshine.  The installation that I did at my home about eight years ago provides 1,000 watts at 120 VAC.  Newer SMA inverters can put out 2,000 watts when the "secure power" feature is activated.  There may be a problem using this feature where rapid shut down is required.

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Stu Besnoff
owner
Alpine Solar Heat and Hot Water, LLC
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Without knowing the details of the system you have, its hard to comment in a specific way. 
As Mike said below, batteries usually have to come into the equation for any meaningful solution.
DO you already have batteries..??, etc.., etc..

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william fitch
Owner
www.WeAreSolar.com
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Original Message:
Sent: 1/12/2023 9:10:00 PM
From: william fitch
Subject: RE: Inverters that allow use of power when provider is down?

Without knowing the details of the system you have, its hard to comment in a specific way. 
As Mike said below, batteries usually have to come into the equation for any meaningful solution.
DO you already have batteries..??, etc.., etc..

------------------------------
william fitch
Owner
www.WeAreSolar.com
------------------------------