diy solar

diy solar

Ground ballast array along front of deck

With "the latest UL 1741SA is the one that includes frequency shift with modulation", if frequency sits at 61.5Hz for a long time, does the inverter remain on-line indefinitely? Or after the time specified by UL 1741SA does it shut off? If shut off, how long before it reconnects?


"Ride through 299 seconds, trip within 300 seconds"

Sunny Boy inverters have up to three modes:
UL1741, just what the standard says.
Island (or off-grid), tolerate a wide range of frequency and voltage variation. Don't drop off and stay off unless frequency exceeds 64.5Hz; otherwise, adjust output up and down.
Backup - given a signal (by RS485 or Speedwire), switch between UL1741 or Island. (I think this is protection in case Sunny Island fails to implement UL1741, for instance if its relay gets welded shut. No explanation of why we should use "backup" not "island" is provided by SMA)

If a GT inverter drops off either immediately or after a delay, the battery has to repeatedly cycle, charging and discharging.
I think only a GT inverter that knows it is in an off-grid or backup configuration, and does not follow UL 1741SA, can perform as desired.
 
I think only a GT inverter that knows it is in an off-grid or backup configuration, and does not follow UL 1741SA, can perform as desired.
I am not sure what your point is here. A GT inverter by definition has to have an external AC signal to function. If that is the case, how could it have an off-grid or backup configuration? We are getting into the weeds here but the conversation could be useful to others. Perhaps a new thread with the appropriate title will attract others with more techincal knowledge than just me.
 
I am not sure what your point is here. A GT inverter by definition has to have an external AC signal to function. If that is the case, how could it have an off-grid or backup configuration? We are getting into the weeds here but the conversation could be useful to others. Perhaps a new thread with the appropriate title will attract others with more techincal knowledge than just me.
Sunny Island, Skybox, and other battery inverters pass through the grid when present. If grid goes down they disconnect from the grid and form a local grid, which allows GT inverters on their output to supply power so you operate off-grid until grid power is restored.

If someone is planning to install grid tie inverters and wants to be able to add backup operation later so their house keeps running during power outages, they should select a grid-tie inverter that lets them use PV during the power outage.

Vendors of battery inverters claim they will work with all grid tie inverters, but that is misleading. Incompatible grid tie inverters will repeatedly connect and disconnect. Fully compatible grid tie inverters able to work also in off-grid battery backup configuration will smoothly adjust their output to exactly match household load consumption and battery charging requirements. They maintain that operation continuously so long as the panels have sun.
 
If someone is planning to install grid tie inverters and wants to be able to add backup operation later so their house keeps running during power outages, they should select a grid-tie inverter that lets them use PV during the power outage.
That is where we started to answer the OPs question. My simple answer to that question is that any GT inverter that is compliant with UL1741SA will allow the addition of a hybrid inverter with that same UL spec. Or for more money than a plain GT inverter they could buy a hybrid that can function without batteries until they want to add batteries. Not all hybrids will run without batteries.
I hope we have answered the OP's question about wheter he is stuck with an Enphase battery solution? To me the answer is, he is not limited to just an Enphase solution for future batteries.
 
To me the answer is that non-Enphase batteries won't make a completely clean/elegant solution. (Don't know about the Enphase battery solution, but I would hope there is communication so it does.) So I would suggest only using Enphase micro inverters if you're going to use Enphase battery inverter.

The SMA solutions available today aren't all officially supported as compatible, so there is an issue with some of them as well.
The current model Sunny Boy is documented as being either strictly grid-tie or strictly off-grid with Sunny Island, not for backup. Their support told me otherwise in an email (which I would retain in case things go South when using a configuration which violates their published documentation.)


I think the European model 8.0H Sunny Island supports Sunny Boy in grid-backup and should be in the US eventually. If SMA confirms that, then could plan to wait for it.
The 400V battery Sunny Boy Storage does support current Sunny Boy for backup.

Some other brands may offer their own compatible solution for grid tie/net metering together with battery backup.

I suggest planning for a system that works well together, not selecting part of it today with only semi-compatible choices for the rest of the system.
 
To me the answer is that non-Enphase batteries won't make a completely clean/elegant solution.
I guess it depends on your definition of "elegant". All I cared about is the frequency Watt functionality that allowed me to leverage my low cost GT system with my DIY battery system.

I suggest planning for a system that works well together, not selecting part of it today with only semi-compatible choices for the rest of the system.
I agree completely. The way I hope to avoid "semi compatable choices" is to use clearly written standards such as UL1741SA and CA Rule 21. I avoid relying on marketing terms.
I hope that this discussion has been helpful to the OP. It is his choice if he wants an elegant solution or one that complies with a standard that works as described. I have no concerns that new UL1741SA compliant Enphase inverters such as the IQ7 line would work with a future hybrid inverter. Mine have proved that assumption.
 
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Instead of a pre-cast footing, consider digging post holes and setting wood or pipe posts like a fence.

If you make a triangular structure properly secured to your deck, it isn't going to go anywhere. The compression/tension strength of a 2x4 or 1" conduit every 8' is all that will be needed to support a rail running horizontally supporting the panels about 2/3 to 3/4 of their length.

You can use commercial mounting rails like these with top or bottom clips to hold panels. With top clips, mount rails in fixed locations, slap panels on top, clamp from top anywhere. With bottom, slide rails to align with holes in panels, hook clip in slot of rail, bolt to panel:


Or you could use pipe and u-bolts, drilling extra holes in panels. Or unistrut (slotted channel). Or wood, maybe carefully locating studs with machine screws to mount panels. Whatever material and design you come up with.

You can look up wind loading at your maximum wind speed. The force it applies is manageable. Only pole-top mounts bending the pole, or very long clear spans, tend to be a problem.
I’m not able to dig deep in this location as it’s very close to the top of leach field. I have enough room for a system like we’ve been discussing, but I dont want to risk hitting anything.
 
That is where we started to answer the OPs question. My simple answer to that question is that any GT inverter that is compliant with UL1741SA will allow the addition of a hybrid inverter with that same UL spec. Or for more money than a plain GT inverter they could buy a hybrid that can function without batteries until they want to add batteries. Not all hybrids will run without batteries.
I hope we have answered the OP's question about wheter he is stuck with an Enphase battery solution? To me the answer is, he is not limited to just an Enphase solution for future batteries.
Thank You for clarifying this as that was a concern. Being locked in to one Vendor or not being able to run all my so.ar power when the grid is down are at the top of list of concerns. While some of your folks technical jargon was over my head, I’m learning as we go so thank you.
 
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