sunny boy inverter?

[SunEagle]

thanks!, my scenario is power outage for a year or something, i also have generator and fuel source that would last "awhile", also i have the emergency outlet on this inverter, i think the max is 2kw output, but was curious how to "trick" the inverter to think it was still grid tie

You can't trick the inverter. It is designed not to work totally unless it is connected to what the grid can provide. It sucks but that is for a safety reason.

[solardreamer]

thanks!, my scenario is power outage for a year or something, i also have generator and fuel source that would last "awhile", also i have the emergency outlet on this inverter, i think the max is 2kw output, but was curious how to "trick" the inverter to think it was still grid tie

Yes you can with any decent pure sine inverter but you need a system that can handle the max watts from all grid tied inverters in your system and you will need to manage excess PV production when your battery is full. For long term outage, it's essentially an off-grid scenario and since you already have a hybrid inverter it's likely more practical to use your inverter in off-grid mode with batteries and generator to charge the batteries when there is not enough PV production.

[SunEagle]

Yes you can with any decent pure sine inverter but you need a system that can handle the max watts from all grid tied inverters in your system and you will need to manage excess PV production when your battery is full. For long term outage, it's essentially an off-grid scenario and since you already have a hybrid inverter it's likely more practical to use your inverter in off-grid mode with batteries and generator to charge the batteries when there is not enough PV production.

I hope you are not posting something that could be unsafe or illegal. Because a grid tie inverter (even with a secure power outlet) is not designed to provide full power if the grid is down.

[mudhole]

Nothing illegal for sure, i am talking if it is an apocolyspe scenario, so yes , it is essentially making a grid tie system into an off grid system was my question...is it cheaper to just purchase an off grid inverter and swap it and add batteries than to try to trick the existing inverter?

[SunEagle]

Nothing illegal for sure, i am talking if it is an apocolyspe scenario, so yes , it is essentially making a grid tie system into an off grid system was my question...is it cheaper to just purchase an off grid inverter and swap it and add batteries than to try to trick the existing inverter?

You are correct. An off grid system will be safer and better then trying to change a grid tie system into working without the grid. Still if we are talking about an apocalypse scenario then IMO having power is not going to help you if you need medications that are no longer being made.

[solardreamer]

I hope you are not posting something that could be unsafe or illegal. Because a grid tie inverter (even with a secure power outlet) is not designed to provide full power if the grid is down.

Don't see anything illegal. It's all done while disconnected from grid. grid tied inverters work just fine with full power provided you have appropriate equipment for an island grid. Just look at Tesla Powerwall when it's disconnected from the utility grid.

[solardreamer]

Nothing illegal for sure, i am talking if it is an apocolyspe scenario, so yes , it is essentially making a grid tie system into an off grid system was my question...is it cheaper to just purchase an off grid inverter and swap it and add batteries than to try to trick the existing inverter?

I doubt it would be cheaper to purchase an entirely separate off grid system of similar size to the grid tied system.

[Mike90250]

Just remember, when faking a Grid with a small inverter, if you solar array is producing 4,000 watts and you are only consuming 2,000 watts, something is going to happen.

Whatever happens, be sure you understand how your small inverter will respond if it suddenly sees 2000 watts coming into it. Will it shut off ? Will it try to frequency shift to control the larger inverter ? Will the larger inverter respond appropriately ? Will all the magic smoke inside be released ?

[SunEagle]

Don't see anything illegal. It's all done while disconnected from grid. grid tied inverters work just fine with full power provided you have appropriate equipment for an island grid. Just look at Tesla Powerwall when it's disconnected from the utility grid.

Unless your system is a hybrid with a battery trying to make a grid tie inverter work fully without the grid can be dangerous and possibly illegal depending on what your POCO and AHJ have approved. Making changes to the inverter to fool it to think the grid is ok is dangerous and IMO illegal.

Completely disconnecting from the grid and having your solar charge a battery or power a small load through a special power connection is ok. As you say having the proper equipment to be an island grid is the way to go in the first place.

[mudhole]

Just remember, when faking a Grid with a small inverter, if you solar array is producing 4,000 watts and you are only consuming 2,000 watts, something is going to happen.

Whatever happens, be sure you understand how your small inverter will respond if it suddenly sees 2000 watts coming into it. Will it shut off ? Will it try to frequency shift to control the larger inverter ? Will the larger inverter respond appropriately ? Will all the magic smoke inside be released ?

great questions to have to think through, are there inverters that have safety switch built in that would cut off in the event you stated?, to bad you cant feed back from the solar array once it was activated to mimick the grid line. How has this been done in the past?

[Ampster]

Yes you can with any decent pure sine inverter but you need a system that can handle the max watts from all grid tied inverters in your system and you will need to manage excess PV production ....

You are defining what a hybrid inverter does when it AC couples to a GT inverter. So the word "decent" should be changed to hybrid and furher clarified by saying UL compliant..
Otherwise uninformed readers could think this is simple when indeed it is complicated. The word fake is also misleading because what a hybrid inverter does is emulate the grid but replaces the infinite load that the grid presents with the controls that the hybrid uses to vary the output of the GT inverter according to the loads on the system.
To answer your subsequent question using a proper hybrid inverter wired correctly is how it has been done and is currently being done. The most current UL spec is UL 1741 SA.

[mudhole]

[QUOTE=Ampster;n423806]
You are defining what a hybrid inverter does when it AC couples to a GT inverter. So the word "decent" should be changed to hybrid and furher clarified by saying UL compliant..
Otherwise uninformed readers could think this is simple when indeed it is complicated. The word fake is also misleading because what a hybrid inverter does is emulate the grid but replaces the infinite load that the grid presents with the controls that the hybrid uses to vary the output of the GT inverter according to the loads on the system.
To answer your subsequent question using a proper hybrid inverter wired correctly is how it has been done and is currently being done. The most current UL spec is UL 1741 SA.[/QUO

so lets say i decide to do another array, i dont want the upkeep of batteries etc, but want to have full power when the sun is shining and it be GT...what i need is to purchase a hybrid inverter, and in the event of loss of grid , i could get both arrays to function?

[Ampster]

.......

so lets say i decide to do another array, i dont want the upkeep of batteries etc, but want to have full power when the sun is shining and it be GT...what i need is to purchase a hybrid inverter, and in the event of loss of grid , i could get both arrays to function?

You could get some hybrids to provide power from only its array without batteries. Not all hybrids work without batteries. However to AC couple with a GT inverter, with any sucess, you would need batteries. The batteries are important to provide the buffer needed to control the GT inverter. The best answers are available by reading the specifications of different hybrid inverters. You should become informed about the technicalities of AC coupling. There are no simple solutions. AC coupling and faking the grid are two entirely different things.

[solardreamer]

You are defining what a hybrid inverter does when it AC couples to a GT inverter. So the word "decent" should be changed to hybrid and furher clarified by saying UL compliant..
Otherwise uninformed readers could think this is simple when indeed it is complicated. The word fake is also misleading because what a hybrid inverter does is emulate the grid but replaces the infinite load that the grid presents with the controls that the hybrid uses to vary the output of the GT inverter according to the loads on the system.
To answer your subsequent question using a proper hybrid inverter wired correctly is how it has been done and is currently being done. The most current UL spec is UL 1741 SA.

Let's stipulate none of this should be attempted by uninformed readers and anyone doing this should do the homework to understand the potential risks for a particular system. Depending on the particular setup and/or local AHJ rules, the grid forming inverter does not necessarily have to be a hybrid inverter or UL compliant.

[solardreamer]

[QUOTE=mudhole;n423807]

You are defining what a hybrid inverter does when it AC couples to a GT inverter. So the word "decent" should be changed to hybrid and furher clarified by saying UL compliant..
Otherwise uninformed readers could think this is simple when indeed it is complicated. The word fake is also misleading because what a hybrid inverter does is emulate the grid but replaces the infinite load that the grid presents with the controls that the hybrid uses to vary the output of the GT inverter according to the loads on the system.
To answer your subsequent question using a proper hybrid inverter wired correctly is how it has been done and is currently being done. The most current UL spec is UL 1741 SA.[/QUO

so lets say i decide to do another array, i dont want the upkeep of batteries etc, but want to have full power when the sun is shining and it be GT...what i need is to purchase a hybrid inverter, and in the event of loss of grid , i could get both arrays to function?

I share your desire to not have to deal with battery upkeep. However, what you want is something lots of others want but no one sells such solution as far as I know. A few commercially available systems can provide full power from GTI without batteries while disconnected from the grid but without batteries the power can be extremely unstable. Think what happens with passing clouds or even birds while you have loads connected.