Enphase IQ8H Microinverter and 595W panel

[vasir13]

Hi,
I got 20 x 595W panels and currently thinking about getting a Sol-ARK 15k AIO system. I am also looking at micro inverters and saw that max wattage for IQ8Hi is 550W. I live in California and the panel setup will not be "ideal" to optimize max generation per panel (facing west) . Of course 595W be is only advertised @ ideal condition. Is there a way for IQ8H Microinverter to fit into my design or is the 595W panel too much to handle?

 

[sunshine_eggo]

Hi,
I got 20 x 595W panels and currently thinking about getting a Sol-ARK 15k AIO system. I am also looking at micro inverters and saw that max wattage for IQ8Hi is 550W. I live in California and the panel setup will not be "ideal" to optimize max generation per panel (facing west) . Of course 595W be is only advertised @ ideal condition. Is there a way for IQ8H Microinverter to fit into my design or is the 595W panel too much to handle?

Why microinverters when you have 15kW of MPPT with the Sol-Ark? It's like you're buying two cars but leaving one parked.

 

[vasir13]

Due to space limitation and the size of the unit. If I go with Sol-Ark then I need to move the unit to my garage which will force me to move the meter closer or some other fancy wire work to make it happen.
Also, I am a bit worried about putting everything in one basket (AIO) and hoping for best vs. micro inverter design. Wonder what the Sol-Ark fail rate is.I like both solutions of course. Looking at Enphase calculator most microinverters support my panel but what is their watt capping limit?

 

[sunshine_eggo]

Then why buy a Sol-Ark at all? Why not just get an inverter?

 

[vasir13]

Want to compare both sides. But for this discussion I would like to know if Enphase micros can handle my panels. I do like Sol-Ark because of its easy permit passing route but as I said before, longevity of Sol-Ark design in not proven yet.

 

[zanydroid]

Why not use HMS2000 microinverters? 500W AC continuous for each of 4 ports

You might even be able to get full amount if you use only 3 ports instead of all 4. Haven’t looked at the specs in a while. But note you need to check whether inflating the AC size will require upgrading panels/feeders or running over POCO limit.

If you are worried about reliability of SolArk… swap in another hybrid inverter when it fails/keep hot spare on the shelf. Get PTO, if SolArk breaks… “you don’t have to replace it with the same one”

 

[fromport]

IQ8H: 384VA
I normally would over panel 125% = 480 Watt panel max.
But that is pure south facing. How much energy do you think you will catch (angle is important).
I would for sure go partly direct connected to the AIO and maybe partly micro if you don't want to have a SPOF.

 

[vasir13]

Why not use HMS2000 microinverters? 500W AC continuous for each of 4 ports

You might even be able to get full amount if you use only 3 ports instead of all 4. Haven’t looked at the specs in a while. But note you need to check whether inflating the AC size will require upgrading panels/feeders or running over POCO limit.

If you are worried about reliability of SolArk… swap in another hybrid inverter when it fails/keep hot spare on the shelf. Get PTO, if SolArk breaks… “you don’t have to replace it with the same one”

Interesting ... (Max. input current: 4 × 16A) ... the panel isc = 18.21A and Current at Pmax = 17.2A ... wonder if the unit will current cap?

 

[vasir13]

IQ8H: 384VA
I normally would over panel 125% = 480 Watt panel max.
But that is pure south facing. How much energy do you think you will catch (angle is important).
I would for sure go partly direct connected to the AIO and maybe partly micro if you don't want to have a SPOF.

So based on your 125% over panel a 540W enphase would do? (595W panel)

 

[zanydroid]

Interesting ... (Max. input current: 4 × 16A) ... the panel isc = 18.21A and Current at Pmax = 17.2A ... wonder if the unit will current cap?

It will probably current cap.

Which panel is this? 18A is unusual. Is that bifacial gain? Paste the spec sheet

You will have a tough time finding micros that match 18A bc of the outlier spec

 

[vasir13]

It will probably current cap.

Which panel is this? 18A is unusual. Is that bifacial gain? Paste the spec sheet

You will have a tough time finding micros that match 18A bc of the outlier spec

Specs attached.

 

[zanydroid]

Specs attached.

Well, these are some monster cells (M12 form factor?). Either switch solar panels to ones that use M10 cells (smaller so lower current), use a string inverter, or accept the overpaneling ratio with majority of microinverters.

And the clipping will be even worse on IQ8H which take max 12A (which is a match for M10 's 13-14A output but way below M12)

 

[vasir13]

Well, these are some monster cells (M12 form factor?). Either switch solar panels to ones that use M10 cells (smaller so lower current), use a string inverter, or accept the overpaneling ratio with majority of microinverters.

And the clipping will be even worse on IQ8H which take max 12A (which is a match for M10 's 13-14A output but way below M12)

Thank you. That was what I was thinking. Or maybe go with 14A micro inverter units. Don't think the panels will ever produce 17 Amps anyways and over time with expected panel degradation things will work out. Panel count is overkill for me (clipping will reduce overall energy output by 1.4 kw optimal) but I got a good deal purchasing them. Only issue is the over current clipping might generate extra heat that can reduce the life expectancy of the micro inverters.

 

[fromport]

Only issue is the over current clipping might generate extra heat that can reduce the life expectancy of the micro inverters.

In general those micro inverters are placed under the panels where they receive a lot of heat from the panels, most of the time with low air flow in 110F/40C+ places. They have been designed for those conditions.
I don't think you will have to worry about temperature issues with micro inverters. That is not my experience with Enphase micro inverters.
I have no experience with the HMS though but I can't imagine them not designing it for the same conditions.

 

[vasir13]

Just spoke with Enphase and they told me that the panels will definitely push the micro inverters (14A DC cont.) . He was unsure if the limited warranty would cover me in this situation which is understandable. Inverter units will report current capping and that might cause warranty issues. Maybe future micro inverters will support these big panels.

 

[fromport]

Just spoke with Enphase and they told me that the panels will definitely push the micro inverters (14A DC cont.) . He was unsure if the limited warranty would cover me in this situation which is understandable. Inverter units will report current capping and that might cause warranty issues. Maybe future micro inverters will support these big panels.

That is an odd thing to hear from Enphase given that they spec the IQ8H together with 320-540+Watt panels according to the specsheet.

There is no hard limit on the wattage but they "are not sure about warranty?"

weird... very weird (imo)

 

[zanydroid]

On the above spreadsheet the max ISC is below what this panel needs but I think I saw another that said 25A. That said Enphase has a tendency already to have rather smaller microinverters and 600W is probably quite the outlier config

HMS goes up to 25A ISC IIRC and the HMS-2000 is specifically targeted to monster panels (though better match to higher voltage with M10 rather than lower voltage with M12)

I believe previous HM was only 15A, also it was for M8 cells (or whatever the size before M10 was, referring to the 10A class)

 

[frasere2]

I think someone mentioned it already, but the IQ8H microinverters have a peak output of 384w, not 550w. You'll be clipping your 595w panels for probably 4-5 months a year. A cheaper, better system would use optimizers with a string inverter. I assume you didn't catch NEM 2.0, so you will need batteries as well. Any DIY retailer can advise you what to use.

 

[vasir13]

I think someone mentioned it already, but the IQ8H microinverters have a peak output of 384w, not 550w. You'll be clipping your 595w panels for probably 4-5 months a year. A cheaper, better system would use optimizers with a string inverter. I assume you didn't catch NEM 2.0, so you will need batteries as well. Any DIY retailer can advise you what to use.

Thank you.
Seems like Sol-Ark if the way to go for me in this case.
I will have 16 panels facing west and 4 facing south due to orientation of my house with no shade. Not fully sold on optimizers and wait a year or so to decide based on data collected. Major issue for me would be now to somehow relocate the smart meter closer to my garage. Do not feel comfortable leaving Sol-Ark outside in hot Sacramento CA Summer. Or install the Sol-Ark in garage which is about 20 feet away from the meter on the other side of the house: PGE -> cutoff-Switch -> (20ft long "3 phase cable" to garage) -> Sol-Ark -> (20ft long "3 phase cable" back to breaker box).
Not happy about the 40ft cable length. Never cared about the NEM2.0 but need to get batteries to satisfy 30% Fed tax break requirement.

 

[zanydroid]

You have to install RSD anyway if it is a roof mount, so deferring optimizer decision is not free given that RSD is baked into optimizer.

Relocating the meter will require POCO permission and be subject to added costs/placement restrictions. It is likely not worth considering unless it is overhead service.

It isn’t a 3 phase cable (it is split phase which is Line/Line/Neutral, while 3 phase will be Line/Line/Line/Neutral), and you can compensate for the distance with larger gauge/cost with using aluminum feeder.

You don’t need pairing with batteries for 30% federal tax credit. You need it to have reasonable return on NEM3 though.

 

[vasir13]

You have to install RSD anyway if it is a roof mount, so deferring optimizer decision is not free given that RSD is baked into optimizer.

Relocating the meter will require POCO permission and be subject to added costs/placement restrictions. It is likely not worth considering unless it is overhead service.

It isn’t a 3 phase cable (it is split phase which is Line/Line/Neutral, while 3 phase will be Line/Line/Line/Neutral), and you can compensate for the distance with larger gauge/cost with using aluminum feeder.

You don’t need pairing with batteries for 30% federal tax credit. You need it to have reasonable return on NEM3 though.

Thank you for the 3 phase correction. You are right, did not think of the RSD and optimizers that way. (still looking at defect rate of average optimizers), maybe spending more on RSD is a simple yet lasting solution?
Can you clarify "You need it to have reasonable return on NEM3 though." ? I dont plan to sell back power to Util.

 

[zanydroid]

Thank you for the 3 phase correction. You are right, did not think of the RSD and optimizers that way. (still looking at defect rate of average optimizers), maybe spending more on RSD is a simple yet lasting solution?
Can you clarify "You need it to have reasonable return on NEM3 though." ? I dont plan to sell back power to Util.

Optimizers add complexity and probably 2-3x the hardware of RSD. With TIGO you get per-panel monitoring with optimization; you can take off optimization but the gap is very low.

You need a battery if you're not selling back to utility.

You need an interconnection agreement if you operate in parallel with utility. If you leave the grid connection disconnected this is guaranteed; if you use some kind of on-demand charging with the grid connection connected then you need to ask around to see if the inverter is truly off-grid. There's a thread here about an AIO that's supposed to be off-grid (can't remember which one) but actually sends some power back. Note that zero export is orthogonal to parallel operation. You can be zero export while operating in parallel with grid.

If you're going to get it permitted anyway you'll probably at least break even on the interconnection fee with the somewhat more than peanuts but not good buyback rate NEM3 gives ($145). Not sure on your time to file it. Since I don't have aggressively anti-NEM/POCO political convictions and I prefer fully code compliant permitted installs anyway I always assume people will just do NEM3.

 

[frasere2]

Thank you for the 3 phase correction. You are right, did not think of the RSD and optimizers that way. (still looking at defect rate of average optimizers), maybe spending more on RSD is a simple yet lasting solution?
Can you clarify "You need it to have reasonable return on NEM3 though." ? I dont plan to sell back power to Util.

The optimizers are like $45 each for panels up to 700w. They produce an extra 10-25% of power per day (real world results) vs a string inverter only. Actually, since you are in San mateo, you can still take advantage of net metering and opt out of the batteries. Double check with peninsula clean energy (peninsulacleanenergy.com/solar-billing-plan/). This would dramatically lower your costs. You can use a much cheaper inverter then. Don't use the enphase microinverters unless you would like to reduce your energy per panel to 380w (that max throughput of that model microinverter). Using optimizers + string inverter will save you $10-15k vs the equivalent production from microinverters. Plus you don't have to buy the batteries so you save another $6-18k.

 

[zanydroid]

The optimizers are like $45 each for panels up to 700w. They produce an extra 10-25% of power per day (real world results) vs a string inverter only. Actually, since you are in San mateo, you can still take advantage of net metering and opt out of the batteries. Double check with peninsula clean energy (peninsulacleanenergy.com/solar-billing-plan/). This would dramatically lower your costs. You can use a much cheaper inverter then. Don't use the enphase microinverters unless you would like to reduce your energy per panel to 380w (that max throughput of that model microinverter). Using optimizers + string inverter will save you $10-15k vs the equivalent production from microinverters. Plus you don't have to buy the batteries so you save another $6-18k.

I don't think PCE Solar Billing Plan is equivalent to NEM2. Unless the roll over extends past generation to T&D (kind of doesn't make sense since PG&E receives the T&D).

Sure, still better than being fully on PG&E Solar Billing Plan.

 

[vasir13]

The optimizers are like $45 each for panels up to 700w. They produce an extra 10-25% of power per day (real world results) vs a string inverter only. Actually, since you are in San mateo, you can still take advantage of net metering and opt out of the batteries. Double check with peninsula clean energy (peninsulacleanenergy.com/solar-billing-plan/). This would dramatically lower your costs. You can use a much cheaper inverter then. Don't use the enphase microinverters unless you would like to reduce your energy per panel to 380w (that max throughput of that model microinverter). Using optimizers + string inverter will save you $10-15k vs the equivalent production from microinverters. Plus you don't have to buy the batteries so you save another $6-18k.

I live in Sacramento and will check with SMUD.