Equipment for 500w panels?

iRenaissanceMan

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My roof space is limited and I wanted to maximize the amount of power I can generate. I need to set up a 15kw system. I've found some Trina 500W panels that I think would optimize my install/roof sqft.

I can't seem to figure what equipment would be compatible with the 500w panels. I was aiming to purchase Enphase products, but their IQ7 microinverters seem to max out at 460W. I saw Solar Edge's equipment... and they do have optimizers that can go to 900w.

Anyone with recommedation on equipment? Also, would you have thoughts on Enphase vs. Solar Edge? I was set on Enphase for ease of handling AC power... maybe you can help convince me to switch to Solar Edge?
 

MPRanger

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Well knowing the watts capable for production is not as helpful as MaxVoltage and OpenCircuit Voltage. An example is purchasing a inverter with a max voltage too low to occupancy your panels in series. Just my immediate thought, but someone else will chime in.
 

iRenaissanceMan

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Thanks! Max voltage is 42.8v

Open circuit voltage is 51.7v

Datasheet for the panel attached.
 

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MPRanger

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OK I am confused" a 15KW system,. I have a couple systems here, the largest is on a 6kw Fronius inverter. I have 25 panels on that system and it seldom reaches 6KW. Are you thinkinking three 500W panels create 15,000 Watts? What are you trying to power? I'm not dissing you, but a Fronius 15K is $4K. https://thepowerstore.com/fronius-primo-15kw-solar-inverter-single-phase-2-mppt-208-240vac.html

Growatt's largest inverter is 12KW I believe and they have not yet started selling the split phase inverter in America yet. The UK has one as does China. You said limited space, so I am guessing you will be happy with a 3KW all in one inverter that supplies a single phase 110V to your trailer.
 
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upnorthandpersonal

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OK I am confused" a 15KW system,. I have a couple systems here, the largest is on a 6kw Fronius inverter. I have 25 panels on that system and it seldom reaches 6KW. Are you thinkinking three 500W panels create 15,000 Watts? What are you trying to power? I'm not dissing you, but a Fronius 15K is $4K. https://thepowerstore.com/fronius-primo-15kw-solar-inverter-single-phase-2-mppt-208-240vac.html

He intends to use micro inverters (i.e., a 'small' inverter that attaches per panel), not a string inverter like the Fronius.
 

iRenaissanceMan

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Sorry, maybe I posted in the wrong forum. I'm trying to install a 15 kW system for my home. I'm planning to install a 30 panels.
 

iRenaissanceMan

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Nope, you're in the right forum. I think there was just some confusion with string inverters vs. micro inverters.
Thanks! Solar edge has the optimizers and they have inverters that look to do 11kw or more. Enphase does the micro tied into the combined. Just trying to figure what would be the right equipment for 500w panels since the specs on the microinverters seem to fall short of 500w.
 

Hedges

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I might not have worried about 500W STC panel vs "460W+" for Enphase, but max 10A Isc for inverter vs. 11.69A Imp & 12.28A Isc looks like a problem.


Your options would seem to be other panels, or other inverters.
Are you required to have Rapid Shutdown for rooftop in your area? Microinverters would have taken care of that. For string inverters, you would need separate RSD box and you'll need one to handle this higher wattage panel.

Microinverters like Enphase let every panel be oriented differently or shaded.
Optimizers like Solar Edge tolerate a certain percentage difference in output due to different orientation, and deal with shading. Strings can be longer than other string inverters allow, because it drops voltage if necessary. The optimizers include RSD.
Conventional string inverters need each string to have all panels oriented the same. They also deal with shading, at least with separate MPPT per string. Paralleled strings can be OK with slight shading. RSD boxes with or without optimizers are available.

If you consider Solar Edge, get Store Edge instead; slight additional cost and you can add battery.
If you might want backup for grid failures, consider what you buy now. If an inverter performs frequency-watts, it should be compatible with an added battery inverter. Enphase and a number of other GT inverters are supposed to have this feature, while some others don't.
 

iRenaissanceMan

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I might not have worried about 500W STC panel vs "460W+" for Enphase, but max 10A Isc for inverter vs. 11.69A Imp & 12.28A Isc looks like a problem.


Your options would seem to be other panels, or other inverters.
Are you required to have Rapid Shutdown for rooftop in your area? Microinverters would have taken care of that. For string inverters, you would need separate RSD box and you'll need one to handle this higher wattage panel.

Microinverters like Enphase let every panel be oriented differently or shaded.
Optimizers like Solar Edge tolerate a certain percentage difference in output due to different orientation, and deal with shading. Strings can be longer than other string inverters allow, because it drops voltage if necessary. The optimizers include RSD.
Conventional string inverters need each string to have all panels oriented the same. They also deal with shading, at least with separate MPPT per string. Paralleled strings can be OK with slight shading. RSD boxes with or without optimizers are available.

If you consider Solar Edge, get Store Edge instead; slight additional cost and you can add battery.
If you might want backup for grid failures, consider what you buy now. If an inverter performs frequency-watts, it should be compatible with an added battery inverter. Enphase and a number of other GT inverters are supposed to have this feature, while some others don't.
Great info! Thank you. You're absolutely right about the short circuit current. I've reached out to enphase for some help. I know both string and micro systems are commonly used, but my gut tells me to buy into the micro system if possible.

Thanks for the tip on Store Edge, I'm going to have to read up on them.
 

Hedges

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"Max DC short circuit current (module Isc)³ 15 A"

That's sufficient

"Peak output power 366 VA"

When sun is lower in the sky you can get all power the panels produce, but it'll clip when panels are able to produce more.

I'm happy with string inverters. I use SMA Sunny Boy.
If rooftop, code may require "Rapid Shutdown" which is an extra expense. If RSD not required (like if ground mount), string inverters should cost less for a given amount of power. To be even more economical, you can have two strings of different orientations connected in parallel. That gives lower peak wattage, more hours, so about 1.4x as many kWh from the inverter.
 

iRenaissanceMan

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Thanks! I totally missed the Peak output power. Let me know if my math is wrong...
The panel's peak outputs are 43V at 11.75amps so 30v RMS and 8.3 amps RMS. Looks like I'll be around 250VA.

I've looked at string and unfortunately, I'll have panels in multiple directions and on different sections of the roof. I hate my complicated install, but it's the lemons I have. :)
 

Hedges

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Don't calculate RMS vs. peak for the panels same as you would for sine wave AC.

At maximum power point, the panel produces 43VDC = 43Vrms at 11.75ADC = 11.75Arms or 505W.

How many of these panels can you fit in each orientation?

Micro inverter per panel like Enphase is one option. Seems like it limits power per panel.

Optimizers as for Solar Edge (Store Edge if you want battery backup) is another option. Probably limited range of compensation for power from different angles. Also find out what power limits.

String inverters like Sunny Boy 7.7 have three MPPT inputs. Each input can have a string of panels of a given orientation.
If Rapid Shutdown is required in your area, find out what power limit the RSD unit has.

If all your PV strings can be same length (each string all panels of one orientation), then multiple strings can be paralleled onto one inverter or one charge controller.
 

kid744

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Can I ask where you found the Trina 500 Watt panels for sale? Hopefully in the US?

Kid
 

BMcL

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This is the best deal I've seen on panels . Bookmarked on Will Prowse's website.
You can pick them up near Dallas ; $218 for 440 watts
 
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