New install 58.4KW - Need some advise SolarEdge HD-Wave vs Enphase IQ6+

[hevnbnd]

Hello,

I have read so many threads my head hurts. I think I have about decided on using SolarEdge HD-Wave with optimizers instead of Enphase IQ6+. Here is the equipment I was looking at:

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LG-330E1C-A5		LG NeON 2 ACe 330w 60-cell, Embedded AC module with Enphase IQ6+ microinverter -177 Modules
EN-ENV-IQ-AM1-240M		Enphase IQ Envoy, single phase
Q-12-20		Q Cable for 60 cell 1.7m lands
Q-Term-01		Enphase IQ Terminator Cap for Q Cable
Q-Seal-01		Enphase Female Sealing Cap for Unused Q Cable Connectors
Racking		Ecolibrium EcoFoot2+ Base, EcoFoot5D Universal Clamp, Wind Deflector

---

LG400N2W-A5		LG LG400N2W-A5 NeON 2 400W 72 Cell Mono SLV/WHT Solar Panel - 146 Modules
P400-5NC4ARM		SolarEdge 400W Power Optimizer w/ MC4 Compatible Connectors
SE10000H-US		SolarEdge HD-Wave 10kW 240V TL Inverter - 15,000 Watts input is max
		Combiner for DC Strings
		Warranty Extention from 12 to 25 years
Racking		Ecolibrium EcoFoot2+ Base, EcoFoot5D Universal Clamp, Wind Deflector

---

With the Enphase option I would need 177 Panels vs 146 with the LG 400W Panels to reach 58.4 KW. The downside with the SolarEdge is the shorter warranty. If I extend the warranty of all the SolarEdge HD-Wave inverters it is an extra $512 each. This makes the SolarEdge about $4,300 more than the Enphase option. I am not sure if I should even go with the extended warranty with the SolarEdge or not. If SolarEdge is reading these threads. They could loose this sale due to a shorter warranty....


So with that said I am really tempted to go SolarEdge. My zip is 72830. The equipment is being installed on a flat roof 18' off the ground. I believe that I will need 6 Inverters. I have been told by SolarEdge that I only need 4 on one call and that I need 6 on another call... Any thoughts would be great.

Also from an installation standpoint it seems that the SolarEdge may be a more challenging installation. Not sure about this though.

Any input on the subject would be great.

[ButchDeal]

5 solaredge inverters would be sufficient. You should not need DC combiners either.
This is a very large installatin for residential, is this a three ohase install?
You will need some kind of interconnect and AC combiner with both systems.

[hevnbnd]

I do have 3 phase 208v. Does this change anything?

Explain the interconnect and AC combiner if you don't mind.

[ButchDeal]

I do have 3 phase 240v. Does this change anything?

Explain the interconnect and AC combiner if you don't mind.

You need to combine all the AC outputs onto a single disconnect.

the 10kw and 11.4kw solaredge inverters have 3 DC string inputs which is all that is needed.

with three phase you should be using the 3 phase inverters

what do you mean you have 3 phase 240 v? 240v is not 3 phase but single phase.
if you have 3 phase 208v then you can use a single inverter.

https://www.solaredge.com/sites/defa...208v_ds_na.pdf

such a large system will almost certainly require a line side tap.

[J.P.M.]

Since you're asking for input, for starters :

What do the economics for such an installation look like, net cost vs. NPV of long term savings after maint. costs/taxes/debt service/etc. ?

What's the panel orientation ? If it's a horizontal layout, the economics will get worse due to lower production than tilted tilted for several reasons including increased cleaning requirements.

If limited roof space is a consideration, know that to a reasonable first approximation, because adjacent rows of tilted panels need a greater row pitch the higher the tilt angle, the production (and electrical billing offset) by an array on a fixed area, horizontal space is somewhat constant as f(panel tilt). That is, after properly spacing panels tilted for max. annual production at some elevation (tilt), the total production from those fewer (and note therefore, less overall cost) tilted panels (but the max. possible for the space after adjacent row shading considerations) will be about the same as the production from a greater number (and more $$) of horizontal panels that cover the entire roof, at least up to the optimum tilt for the location and application. People with skin in the game may not have mentioned that. They make $$ providing equipment, not necessarily providing the most cost effective systems.

If,after the project is shown to be potentially both economically viable and possible, I'd start the preliminary design dropping the wind deflectors. They won't improve performance, and may even impair performance a bit. Long story. If aesthetics are a consideration/reason for selecting wind deflectors, use black racking, make the rack edges close to flush with the panel edges and paint the racking cut edges black. Aesthetics will be effectively the same. Performance/production will be a bit better. Wind loading(s) will be essentially the same in either case, maybe a bit less w/out the deflectors.

Plan for access to all the panels for cleaning and maintenance. Lots of penetrations in a flat roof will need access if for nothing more than regular inspection. If you don't already know this, it's a bad idea to walk on an array. Doing so usually comes to a bad end. Tilted arrays with suitable row pitch handle the access requirements quite nicely.

As for a ballasted system that large (if that's being considered), I seriously doubt a flat roof not intentionally designed for it take that much dead or other loadings imposed by such a large system without careful considerations. Just sayin'.

Why such high end panels ? Same/similar quality and performance can be had for less money. Panels are pretty much a commodity these days. I'd shop around and get knowledgeable.

This is a good place to get information to fill in knowledge gaps, but without a foundation in the basics, there will be no gaps to fill in. Get familiar with the fundamentals and you'll have the highest probability of getting a better, safer and more fit for purpose system (if any after the education shows the project is not viable or sensible), and you'll have fewer headaches from reading threads that are talking about stuff you may not fully understand (yet).

Good luck.

That what you want of the above. Scrap the rest.

[hevnbnd]

You need to combine all the AC outputs onto a single disconnect.

the 10kw and 11.4kw solaredge inverters have 3 DC string inputs which is all that is needed.

with three phase you should be using the 3 phase inverters

what do you mean you have 3 phase 240 v? 240v is not 3 phase but single phase.
if you have 3 phase 208v then you can use a single inverter.

https://www.solaredge.com/sites/defa...208v_ds_na.pdf

such a large system will almost certainly require a line side tap.

Sorry It is 208 3 Phase. Looks like the 3 Phase inverter is a lot less than 5 240 inverters.

[hevnbnd]

Since you're asking for input, for starters :

What do the economics for such an installation look like, net cost vs. NPV of long term savings after maint. costs/taxes/debt service/etc. ? In Arkansas we can use excess power created on any other accounts we might have with our local power company. I currently have around $500 monthly usage. So the purpose for an array this size is to cover all my properties utilities.

What's the panel orientation ? If it's a horizontal layout, the economics will get worse due to lower production than tilted tilted for several reasons including increased cleaning requirements.Panels are portrait facing South with a 10 degree tilt.

If limited roof space is a consideration, know that to a reasonable first approximation, because adjacent rows of tilted panels need a greater row pitch the higher the tilt angle, the production (and electrical billing offset) by an array on a fixed area, horizontal space is somewhat constant as f(panel tilt). That is, after properly spacing panels tilted for max. annual production at some elevation (tilt), the total production from those fewer (and note therefore, less overall cost) tilted panels (but the max. possible for the space after adjacent row shading considerations) will be about the same as the production from a greater number (and more $$) of horizontal panels that cover the entire roof, at least up to the optimum tilt for the location and application. People with skin in the game may not have mentioned that. They make $$ providing equipment, not necessarily providing the most cost effective systems. Roof is 48' x 120' so space is ample. The inside is totally being gutted so I can bring all penetrations up at same location if needed. Existing penetrations will remain but will not need accessed.

If,after the project is shown to be potentially both economically viable and possible, I'd start the preliminary design dropping the wind deflectors. They won't improve performance, and may even impair performance a bit. Long story. If aesthetics are a consideration/reason for selecting wind deflectors, use black racking, make the rack edges close to flush with the panel edges and paint the racking cut edges black. Aesthetics will be effectively the same. Performance/production will be a bit better. Wind loading(s) will be essentially the same in either case, maybe a bit less w/out the deflectors. Thanks I thought these were useless. I have 1 foot parapet walls. Aesthetics do not matter.

Plan for access to all the panels for cleaning and maintenance. Lots of penetrations in a flat roof will need access if for nothing more than regular inspection. If you don't already know this, it's a bad idea to walk on an array. Doing so usually comes to a bad end. Tilted arrays with suitable row pitch handle the access requirements quite nicely.

As for a ballasted system that large (if that's being considered), I seriously doubt a flat roof not intentionally designed for it take that much dead or other loadings imposed by such a large system without careful considerations. Just sayin'. Structural engineer is supposed to look at roof tomorrow. So far everyone is planning on doing a ballasted array.

Why such high end panels ? Same/similar quality and performance can be had for less money. Panels are pretty much a commodity these days. I'd shop around and get knowledgeable.Not stuck on LG Panels. However If I went enphase that LG panel seems to be the cheapest option. If I go SolarEdge that opens up a lot more panels. Also go a quote on JA Solar 330W panels for about 14K less. Has more panels though to make same output.

This is a good place to get information to fill in knowledge gaps, but without a foundation in the basics, there will be no gaps to fill in. Get familiar with the fundamentals and you'll have the highest probability of getting a better, safer and more fit for purpose system (if any after the education shows the project is not viable or sensible), and you'll have fewer headaches from reading threads that are talking about stuff you may not fully understand (yet).

Good luck.

That what you want of the above. Scrap the rest.

Thanks for all the information

[ButchDeal]

Sorry It is 208 3 Phase. Looks like the 3 Phase inverter is a lot less than 5 240 inverters.

You also only need the one and no need for an AC combiner, and half the optimizers as well

[hevnbnd]

You also only need the one and no need for an AC combiner, and half the optimizers as well

Why only half the optimizers?

[J.P.M.]

Thanks for all the information

You are most welcome.

Using back of envelope math and a 8 year simple payback, you'll need an installed net cost after tax credits of ~ $48K (= 8 years * $6,000/yr.) That boils down to $48,000/58,400 STC watt system >>> ~~ $0.82/STC W. Even if that's after tax/other credits/rebates, that's kind of a low price, particularly given the engineering and other things involved . If this is for a business, other tax consequences/breaks may apply. Still, getting all that stuff up to and somehow affixed to a flat roof 18' off the ground for $0.82/STC W may be a challenge.

You might find pallet quantities only for that per watt price, but that doesn't include the balance of system materials, shipping, engineering, permitting or any labor.

So, what's your budget for the whole project ?

As for available area, you've got something like a 3,100/5760 = .538 coverage ratio. Probably OK, but not as liberal or open as you might think. Depending on array elevation off the roof, the parapets will also reduce available/reusable roof area. That 10 deg. tilt will also require more cleaning and snow removal considerations than a higher tilt will require (although the higher tilt will still have those same considerations, just, hopefully, less pronounced). If I did this project at all, I'd consider a higher tilt angle and increase the row pitch by the required amount balanced against system performance and economics to get ~ the same annual output, a bit less cost and easier maint/cleaning.

For that matter, if area is available, and because ballasted systems, particularly, and as a practical matter on large, existing flat roofs,hard if not impossible to get reasonably safe and fit for purpose, I'd consider a ground mount. Less hassle, but with the drawback of probably a higher project cost. Still, less hassle/maint. vs. more cost/tradeoffs.

From PVWatts, looks like an unshaded south facing 58.4 kW array near/around zip 72830 at 10 deg. tilt will produce ~ 78,000 - 80,000 kWh/yr. If that's close to your annual load (from the stated goal of a 100% offset), and from your statement that your paying $500/mo. = ~ $6,000/yr. for electricity, looks like your cost per kWh is something like $0.075 or so ? = ~ ($6,000/yr)/(80,000 kWh/yr.) If so, the numbers on simple payback on a price of something like $0.82 net /STC W/$0.075/kWh ~ 11 years. But that low cost of $0.82/STC W seems more optimistic than I'd want to put a lot of faith in as described above, making even the 11 yr. payback way optimistic.

And all that's using the moron payback method of initial cost/1st yr. savings before any serious financial number crunching involving cost of money or life cycle cost analysis. Any such real financial analysis and considerations will probably show even less optimistic financial returns.

If the wind loading is done correctly, be prepared for a bit of sticker shock at the amount of ballast it will take to keep the array in one place, and don't be surprised if the flat roof, particularly of that size, needs some reinforcement and/or modification. Ask your structural engineer about any familiarity with ASCE/SEI 7-10. That's the common/accepted wind loading requirements most governing building specs, professional engineering and common sense seem to be following these days. The answer (or the possible dumb looks) you get back may be enlightening.

BTW, any tornado considerations ?

If it was me, I'd forget ballasting and proceed on the basis of an anchored system for the design if I did anything it at all, which, FWIW, is beginning to look doubtful to me given what's beginning to look like lousy economics from my uninformed view.

Take what you want of the above. Scrap the rest.

[ButchDeal]

Why only half the optimizers?

3 phase inverters use different optimizers that use two PV modules each.

[bcroe]

Those panels WAY out perform mine, might be cheaper to use a few more of more generically priced panels. As
was pointed out, fewer panels with an optimum tilt, and spaced to avoid shadow, will collect just as much energy
as more panels lying flat, and occupy the same space. The tilt and the spacing will make any snow clearance a
far more practical matter; it would be quite a problem with jammed together flat panels. Do keep the lowest part
of the panels well above the roof if you expect any snow accumulation.

If you laid 6 panels of 60 cells end to end, they would be only a couple inches longer than 5 panels of 72 cells.
And series to the same voltage. So pick the one that fits into your plan best, I find 60 cell a lot easier to handle
and a bit cheaper per watt.

Check that your AC line voltage is well within the range of the inverter, to avoid
tripping off from excessive voltage under best sun. Bruce Roe

[hevnbnd]

We don't know what snow is here....

[bcroe]

We don't know what snow is here....

That will simplify things. I have seen snow in FL and TX. Bruce Roe

[philips]

what do you mean you have 3 phase 240 v? 240v is not 3 phase but single phase.

Just FYI - 240 3 phase is a real thing - typically in a high leg delta config - see it in older commercial buildings around here.