Activate solar in an emergency

[wanabee solar]

OP has a 7.6kW grid tie which would require at least 8kW of bimodal and batteries capable of taking the full charge of 7.6kW

If the grid inverter is in zero grid mode would that be more practical?

[SunEagle]

If the grid inverter is in zero grid mode would that be more practical?

Please understand that any legal standard "grid tie" inverter will never work if the grid is down. The only inverters that can work without the grid are; "grid tie" with the secure power option, hybrid inverters with a battery system or "off grid" inverters with a battery system.

Plain and simple. You can't "fool" a "grid tie" inverter due to the safety software built in to it that looks for a "grid". There isn't any device that can mimic a grid to make the inverter work.

[ButchDeal]

If the grid inverter is in zero grid mode would that be more practical?

Nope as there will very short bursts of higher current. The bimodal needs to be capable of AC coupling and be larger than the grid tie system.

[nwdiver]

Plain and simple. You can't "fool" a "grid tie" inverter due to the safety software built in to it that looks for a "grid". There isn't any device that can mimic a grid to make the inverter work.

AC couple inverters can 'fool' a grid-tie inverter. My Magnum 4448PAE works fairly well with my 8kW SMA Sunnyboy. I can pull 2/3 fuses if I'm worried about the SMA over powering the Magnum since I should have 2 Magnums to absorb the output of the SMA. There are a few other AC couple capable inverters out there like the Outback radian. As far as I know all grid-tie inverters are able to AC couple since AC coupling is designed around the UL1741 standard.

Lithium or golf cart batteries if I did?
shem

IMO Golf cart batteries would be the better choice for an AC couple 'emergency' back up system. The AC couple inverter really can't control the charge rate to the batteries when in AC couple mode. It's dumping all the surplus energy from the grid-tie into the batteries, when the batteries are full it trips the grid-tie by frequency shifting. Flooded batteries can handle overcharging much better than lithium. There are dump controllers available but that obviously adds to the cost.

[SunEagle]

AC couple inverters can 'fool' a grid-tie inverter. My Magnum 4448PAE works fairly well with my 8kW SMA Sunnyboy. I can pull 2/3 fuses if I'm worried about the SMA over powering the Magnum since I should have 2 Magnums to absorb the output of the SMA. There are a few other AC couple capable inverters out there like the Outback radian. As far as I know all grid-tie inverters are able to AC couple since AC coupling is designed around the UL1741 standard.




IMO Golf cart batteries would be the better choice for an AC couple 'emergency' back up system. The AC couple inverter really can't control the charge rate to the batteries when in AC couple mode. It's dumping all the surplus energy from the grid-tie into the batteries, when the batteries are full it trips the grid-tie by frequency shifting. Flooded batteries can handle overcharging much better than lithium. There are dump controllers available but that obviously adds to the cost.

You did not read my post completely.

The 8kW SMA Sunnyboy inverter has the secure power option which allows "2kW" of the solar array to generate power without the grid but never the entire 8kW. That type of inverter is one of the 3 non standard kind I mentioned in my post.

[nwdiver]

You did not read my post completely.

The 8kW SMA Sunnyboy inverter has the secure power option which allows "2kW" of the solar array to generate power without the grid but never the entire 8kW. That type of inverter is one of the 3 non standard kind I mentioned in my post.

My inverter doesn't have 'secure power' it's an older 2012 model. I AC couple the output with the Magnum 4.4kW.

[motorcyclemikie]

there are several YouTube videos on how to emulate the grid, and accomplish what you are after. it needs a little bit of work and you need some creativity

[SunEagle]

there are several YouTube videos on how to emulate the grid, and accomplish what you are after. it needs a little bit of work and you need some creativity

And I do not feel that any youtube video that shows someone how to fake out the grid tie inverter is safe. Especially for people that can't determine the difference between a kW / kWh or understand the requirements for proper over current protection.

I understand that someone will find a way to DIY a system that bends the rules but I will not condone those videos on this forum.

If you don't like my response then take it up with the Admin.

[ButchDeal]

Both Magnum and Outback have AC coupled inverters specifically designed to 'fake out' the grid tie inverter. It's as safe as any other PV system.

https://www.magnum-dimensions.com/si...g-Rev-5-10.pdf

As repeatedly posted in this chain, there are ways to properly configure an AC coupled system that generally require a larger (in this case at least 8kW) bymodal inverter.
These are NOT "faking out" the grid tie but actively managing it. The OP was asking about a small off grid and car battery system which is NOT going to be safe or able to handle anywhere close to 7.6kW of charging.

[nwdiver]

These are NOT "faking out" the grid tie but actively managing it.

Yes, AC coupled inverters are designed to actively manage the output of the grid-tie. Which is why 'fake out' was in 'quotations'. I agree that ~9kW of AC coupled inverter would be the right way to do it but even that isn't really that expensive. <$5k probably.

Depending on the inverter it could also be possible to SW limit a 8kW to ~4kW allowing them to safely limit the output of the grid-tie so they could AC couple to a smaller inverter 'in an emergency'. Is that the theme of this thread? Solar in an Emergency?

And the video I linked to wasn't some crazy DIY'r it was a legit PV sales site simply explaining how AC coupling works....

[motorcyclemikie]

And I do not feel that any youtube video that shows someone how to fake out the grid tie inverter is safe. Especially for people that can't determine the difference between a kW / kWh or understand the requirements for proper over current protection.

I understand that someone will find a way to DIY a system that bends the rules but I will not condone those videos on this forum.

If you don't like my response then take it up with the Admin.

yes never let a YouTube video force you into an unsafe condition. anything that you see on a YouTube video you must understand you do at your own risk it can be risky! very good point, thank you sun!

[ButchDeal]

Yes, AC coupled inverters are designed to actively manage the output of the grid-tie. Which is why 'fake out' was in 'quotations'. I agree that ~9kW of AC coupled inverter would be the right way to do it but even that isn't really that expensive. <$5k probably.

Possibly though that would be much more complex and specific install and unlikely to find a ytube video on.
as for <$5k possibly could get a 9kw inverter capable of AC coupling and management for under $5k but would also need a battery capable of taking a 7.6kW charge and various electrical components that would likely drive up the cost. It is all a far cry from OPs original question of a car battery and small inverter...

Depending on the inverter it could also be possible to SW limit a 8kW to ~4kW allowing them to safely limit the output of the grid-tie so they could AC couple to a smaller inverter 'in an emergency'. Is that the theme of this thread? Solar in an Emergency?

yes and no. The OP asked :

What If I took a car battery and a small inverter and put power to those wires? Would that activate the inverter?

and the comment that you are following on is about getting some Ytube BS about doing the same unsafe and unlikely to work procedure as apposed to a real bimodal inverter properly installed for emergency backup and AC coupled.

[nwdiver]

and the comment that you are following on is about getting some Ytube BS about doing the same unsafe and unlikely to work procedure as apposed to a real bimodal inverter properly installed for emergency backup and AC coupled.

The video I linked to that was deleted clearly explained that you need a bimodal inverter properly installed for emergency backup....

[ButchDeal]

The video I linked to that was deleted clearly explained that you need a bimodal inverter properly installed for emergency backup....

possibly though you are getting mixed up with another poster suggesting youtube videos etc. and your suggestion of using a bimodal of half required size is in some ways better but in other ways worse. The small inverter with a battery is unlikely to get a grid tie inverter functioning so safer, but the too small bimodal will (as you mention) but could cause a dangerous situation.

Of all the different types of installs an AC coupled is the most critical to have a knowledgable person configure and maintain is it has the most potential for danger from a configuration problem...and at the same time AC coupled are the most complex (with regard to residential systems of the various type of configurations common in residential, string, optimized, micro, DC coupled bimodal, AC coupled).
Thus one should be very cautious in any AC coupled advice given

[SunEagle]

yes never let a YouTube video force you into an unsafe condition. anything that you see on a YouTube video you must understand you do at your own risk it can be risky! very good point, thank you sun!

Thank you for your understanding.