Mounting inverter in Phoenix: Garage or Outside?

[Volusiano]

Giving it a little more thought, I still don't quite get how my installer came up wtih +$4000 for a 2 inverter setup. We didn't talk specifics on which inverters, maybe he assumed two of the Fronius, but why would he?

Looking online, the Fronius 11.4 can be had for $3219 while the Power One PVI-6000US is $2,277, or $4554 for two. He said a combiner box is about $400 of the price plus additional labor and such...but still, it shouldn't be more than an additional $2,000...say $2500, but $4000?

Wow, $400 for the combiner box? I don't claim to know the pricing, but at a quick glance it's just a simple metal box with connection hardwares on the inside. I may be wrong but I don't think there's fancy electronics involved inside. Seems like it should be around $40 instead of $400. Maybe someone more knowledgeable on the pricing can chime in here.

[inetdog]

Wow, $400 for the combiner box? I don't claim to know the pricing, but at a quick glance it's just a simple metal box with connection hardwares on the inside. I may be wrong but I don't think there's fancy electronics involved inside. Seems like it should be around $40 instead of $400. Maybe someone more knowledgeable on the pricing can chime in here.

An AC combiner box is (or can be) essentially a standard sub panel with breakers inside.

You can pay $400 for a breaker box and four breakers if you choose an expensive brand and buy individual parts. But even if you go for a package deal, getting all the way down to $40 will be difficult if not impossible.

Unless the manufacturer is a UL approved panel shop, you will be paying for a standard assembly which is UL listed for use as a sub panel as well as for use as an AC combiner.
Even if the individual inverters contain output breakers, the NEC requires you to put a branch circuit breaker for each one at the combiner.

[HX_Guy]

Looking on Google, I'm seeing prices of $85 - $600+ for "Solar AC Combiner Box" so I guess it's possible, I have no idea which one he was specing out.

I did email them last night with links to the inverters, showing a difference of about $1200 between two smaller PowerOne inverters and one big Fronius inverter and asked if they could do it for $2000 installed. I'll see what they say today.

[Mb190e]

My installer offered me 1 inverter or 2 it was up to my choice, after doing some research I opted for 2 and it was no extra cost. the same price either way. It was a little bit more work installing, had to hang 2 inverters extra materials and installation of the secure power supply and combiner box.

[HX_Guy]

Much better now....

Yes, the situation where you have one full panel shaded or four or five 1/3 panels shaded will likely give you zero output from both strings.
But if you connect the two of them to their own shared MPPT input they both should be able to produce.

Integ: Can you help me understand this spec sheet for the PVI-6000-OUTD-US inverter?

It shows that the "Full Power MPPT Voltage Range" is 200-530 but then says "Operating MPPT Voltage Range" is 0.7xVstart - 580.
What's the difference between Full Power MPPT Voltage Range and Operating MPPT Voltage Range?

And it says the Vstart is 200 but adjustable between 120-350...so why wouldn't you set that as low as possible (120) so that the system would start up faster as it reaches that voltage? And if you set it to 120V Vstart, then the MPPT operating range would be 84V? Seems the lower the voltage the better it would be if there are shade issues, no?

[HX_Guy]

Bah! Heard back from the installer and they're saying +$3800 for the 2 inverter setup with the inverter price being +$1000 per inverter ($3500 for (1) Fronius and $2500 each for the PowerOne. Then the UL combiner box at $350 and the rest for conduit, wiring and 6 hours of additional labor. He is saying that it's basically like installing two systems because per code, he can't run all the wires in one conduit, he will have to run two sets of conduit, one for each inverter...is that correct?

I'm trying to see if they will come down on the price some more, if I can get it to $3000 I think I would do it. Just seems like a much better way to go between the better inverter (operating temp of 160º, derate after 122º vs operating of 122º, derate after 104º of the Fronius) plus having each string on it's own MPPT and not losing the south roof strings for basically 4-5 months out of the year.

[silversaver]

Bah! Heard back from the installer and they're saying +$3800 for the 2 inverter setup with the inverter price being +$1000 per inverter ($3500 for (1) Fronius and $2500 each for the PowerOne. Then the UL combiner box at $350 and the rest for conduit, wiring and 6 hours of additional labor. He is saying that it's basically like installing two systems because per code, he can't run all the wires in one conduit, he will have to run two sets of conduit, one for each inverter...is that correct?

I'm trying to see if they will come down on the price some more, if I can get it to $3000 I think I would do it. Just seems like a much better way to go between the better inverter (operating temp of 160º, derate after 122º vs operating of 122º, derate after 104º of the Fronius) plus having each string on it's own MPPT and not losing the south roof strings for basically 4-5 months out of the year.

If you are spend that much more money, try solaredge then. It will also take care of your shading issue.

[HX_Guy]

Hmm, that could be an option. Would the rest of the install, aside from plugging in the optimizers, be the same as doing a regular 1 inverter install?
Looks like to get the most out of the system, you need to use a SolarEdge inverter as well, but the price seems good at around $2500.

[silversaver]

Hmm, that could be an option. Would the rest of the install, aside from plugging in the optimizers, be the same as doing a regular 1 inverter install?
Looks like to get the most out of the system, you need to use a SolarEdge inverter as well, but the price seems good at around $2500.

There will be single inverter + the power opti on panels. I think it is a much better choice for you and your challenge lol hahaha

http://www.solaredge.us/

[HX_Guy]

Great...more things to research!

Seems orientation and string length does not matter between strings so I could have 14 east and 8 south and 12 west if I wanted. Minimum of 8 panels per string and maximum of 25.

http://www.solaredge.com/files/pdfs/products/power-optimizers/se-power-optimizer-ao-datasheet-na.pdf

[silversaver]

Great...more things to research!

Seems orientation and string length does not matter between strings so I could have 14 east and 8 south and 12 west if I wanted. Minimum of 8 panels per string and maximum of 25.

http://www.solaredge.com/files/pdfs/...tasheet-na.pdf

Do you see why I said on previous post "mission impossible"? I have follow your thread and I think you have doing your home work. I saw that your have shading issue and still want to use string inverter... That is why I keep saying mission impossible...

Enphase is good choice, but not a good choice for your area since you have extreme high temp summer. Try solaredge, I think it might be a better option for you since your shading is not just "a little". I am not a solar expert, but if this is my solar project, I'll choose solaredge.
Good luck.

[HX_Guy]

I talked to my installer and they have no experience with SolarEdge, never used or installed it. They have done micro-inverters and he said it's probably similar on the panel install side. He did say micro-inverters need some sort of extra ground that's not needed when doing a string inverter? Is the same true for SolarEdge?

Price wise, the SolarEdge inverter and 48 optimizers would be about $5,400 going by online prices. He said the Fronius inverter is $3,500, so looking at +$1,900 minimum. I'm sure they would upcharge it a bit but shouldn't be more than +$2,500 I wouldn't think vs the old Fronius install. But, the SolarEdge has built in wi-fi monitoring *I think* where as with the Fronius it's an additional $800 and it's a must for me, so really the net additional would be +$1,100.

[Mb190e]

6 additional hours of labor to put in an additional inverter! I think it only took my guy eight hours to install everything 2 inverters, 2 DC disconnect, 2 secure power supplies, trough, combiner box, meter, disconnect and mount the sheet of plywood to the wall.

[silversaver]

You should see how my installer charge me 6 hours X 2 labor = 12 hours to do a 2 panels addition. lol

[Volusiano]

Bah! Heard back from the installer and they're saying +$3800 for the 2 inverter setup with the inverter price being +$1000 per inverter ($3500 for (1) Fronius and $2500 each for the PowerOne. Then the UL combiner box at $350 and the rest for conduit, wiring and 6 hours of additional labor. He is saying that it's basically like installing two systems because per code, he can't run all the wires in one conduit, he will have to run two sets of conduit, one for each inverter...is that correct?

I'm trying to see if they will come down on the price some more, if I can get it to $3000 I think I would do it. Just seems like a much better way to go between the better inverter (operating temp of 160º, derate after 122º vs operating of 122º, derate after 104º of the Fronius) plus having each string on it's own MPPT and not losing the south roof strings for basically 4-5 months out of the year.

I have 44 panels (11KW system) all in one place on the roof (not spread out like yours). My installer ran all the wires inside a single conduit down through the attic to the other side of the house where the garage is. From there, this single conduit goes into a splitter box, and from there split out into the 2 inverters, then the inverters go into the combiner box before going into a dedicated meter for the solar system, then to an ON/OFF switch box before going into the main circuit panel.