Sanity Checking + Advice on SolarEdge

[Magius]

Hello everyone. This is my first post but I've been scouring this forum for a few weeks now, absorbing tons of great info. I'm getting ready to take the plunge on a decent sized system (57 modules) to offset both my home's usage and an electric car.

I've been negotiating with two installers directly, and have comparative data from two freinds who recently installed solar and cross-shopped a few different installers themselves. As such, I'm fairly confident that the pricing I have is pretty good for my area. I have options available from $1.89/W for Hyundai 285W panels on SMA Sunnyboy up to $3.42/W for SunPower X21 335W panels with SolarEdge/Enphase, and various combinations of panels/inverters in between. I've run the numbers every which way possible and decided I'm going to go with LG Neon2 320W panels, and strongly leaning towards pairing them with SolarEdge. The corresponding quote for that setup is:

57x 320W LG Neon2 (18.24 kW) + 3x SE6000A & optimizers = $42,864 @ $2.35/W (~$1.65/W after 30% tax credit)

Now, the main question I have is whether I'm doing the right thing w/ SolarEdge... Due to my roof layout I'll be putting modules on all of the east, south and west surfaces. This is all 2nd story roof with no shading (other than clouds) but due to the 3 orientations across 7 roof faces (21 modules on one face, 4-7 each on 6 other faces) I decided against a plain string inverter setup (told the installers not even to quote them). I'm also a tech geek and I want per-panel monitoring, so sue me . I was originally planning for panels around 300W and had asked the installer for Enphase, but when we decided to step up to the 320's he was concerned about clipping. Plus, the more I've looked into Enphase as a company it makes me nervous betting that they'll be around any significant amount of time to honor warranties on my 57 inverters So I took the installer's recommendation and had him switch the quote over to SE.

My only major concern with SE is that it's a 100% proprietary system, and while they seem to be rolling in cash now, if anything happens to them down the road (10-15 years) it seems like you're pretty well screwed when your inverter dies (and I'd be rolling the dice with three of them). I shared this with both of my installers, and the other one said that he had the same concerns, so for that reason he installed SMA + Tigo on his own house. I've done research on Tigo, and it seems like a good product, but there's so little information out there compared to the other options it makes me wonder. Most of the information on Tigo that's not direct from their website seems to be 3-6 years old, and hard to tell if it's still relevant. For example many sites claim that if a Tigo optimizer fails the whole string goes dead, but it seems as if that's not true anymore, if it ever was at all. Even searching this forum the number of hits on Tigo were very slim compared to the amount of posts and recommendations on all the other options. One small bonus from recent news, w/ SMA buying a large stake in the company, I'd suspect Tigo's future is about as solid as you could really be in the solar industry...

All that said, I'm curious if anyone has any *current* insights on the Tigo system and how it compares to a SolarEdge system (overall, including lets say SMA inverters - my installer doesn't like Fronius for some reason). The installer that recommended Tigo is not the one whose quote I referenced above with LG+SE, so I don't want to open a new can of worms by suggesting Tigo to the other guy, unless I'm really convinced it's a better way to go. Right now it seems like a slightly less capable version of SE to me, with the guarantee that I can't be screwed when my inverter eventually dies. Anyone think there's more to the comparison than that?

Any other thoughts would be appreciated as well, but I'm fairly sure at this point that I've ruled out both Enphase and non-optimized strings, so that doesn't leave me with many options, regardless of my concerns about SE and their proprietary risks. Thanks a lot!

[ButchDeal]

First off WHY oh WHY are you putting in THREE solarEdge inverters. And particularly the SE6000. I could see if you were trying to get ready for powerwall and put in the SE7600 but three SE6000 is silly.
I would do this with most likely two SE7600 or one SE11400 and one SE5000

Due too the arrangement on 3 azimuths you would have little clipping if any.

We have had problems with Tigo monitoring, maybe SMA will make it better in the future

[pclausen]

I'll throw out another option. Ubiquiti sunMAX. Here's a link:

https://sunmax.com/

I just completed an 80 panel install (56 on the roof and 24 on a ground mount).



Solar is a relative new division for Ubiquiti, they are primarily known for network equipment, especially WiFi and WISP. They are financially strong and well diversified and their solar products are very competitively priced at about $1.50/W (plus installation).

Their 250W microinveters runs right around $100 a pop and use low power Bluetooth to communicate to one or more solar gateways, which are in turned connected to your network via Ethernet. You can ssh or point a browser to the gateways, which also send stats to the cloud, where you can also check/track the status and production of your system.

No affiliation, just a happy customer.

[solarix]

With any system that puts electronics under each PV panel, think about what you are going to do some day when they start failing one by one....

[emartin00]

I like the SolarEdge system. Just installed an SE6000 at my parents house. The optimizers have better reliability than Enphase, and you still get the benefits. SolarEdge is now the leading inverter manufacturer, passing Enphase this year IIRC.
Tigo looks nice, having the ability to use any inverter, but they are still a bit too new. I would like to see a little more positive data on them first.

[Magius]

First off WHY oh WHY are you putting in THREE solarEdge inverters.

All I can really say about this was that it was not my design, but I think I'm happy enough with it? Initially I had asked for Enphase, and when we changed to SE the original proposal was for 57x SolarWorld 300W panels with 3x SE5000A inverters. I wrote the installer back and asked why he would go with 3x 5kW inverters instead of two of the 7600W. My argument was that it would be cheaper to go with 2x 7600's, plus I had some concerns about how he might decide to configure the strings across three inverters, since we haven't really talked about that level of "back-end" detail yet. I didn't get an exact response to my question, because before he was really forced to answer it we ended up upgrading the proposal to the 320W panels, along with him bumping the inverters up to 3x 6kW. I decided not to ask him again about the 2x 7600W, since that would be 18.24kW DC going into 15.2 kW AC, or about 20% oversizing. Not that there's anything "wrong" with that, but if he wants to do 3 inverters, and the price seems right, should I really make a bigger deal about it? Would I be that much better off with one 10-11kW and one 5-6kW (~$3100?) instead of the 3x 6kWs (~$3600?)? Lets assume he isn't willing to alter the price of the job either way, would you still recommend doing it with the two inverters just to have less chance of inverter failure? I'm sure I could convince him to do it that way if it's worthwhile and let him pocket a little extra profit...

Thank you for sharing your experience with Tigo as well!

[Magius]

I'll throw out another option. Ubiquiti sunMAX. Here's a link:

https://sunmax.com/.

Thank you for that info. I'm rigging my house up w/ Ubiquiti APs, and I have my eye on one of their 10GbE switches for the future, but I had no idea they were in the solar business. The issue I see here is that their microinverters are only 250W, and I'm planning on 320W panels. That's too much oversizing factor IMHO, even though I fully understand the concept of "right sizing" and the panels not putting out their nameplate ratings. I might ask the installer if he's ever heard of it, just for fun, but I wouldn't him to switch over to it. Thanks though for sharing an alternative to Enphase!

[Magius]

Tigo looks nice, having the ability to use any inverter, but they are still a bit too new. I would like to see a little more positive data on them first.

This is where I'm at. The product is relatively new, however most of the reviews, comparisons, etc. are quite old. Reading reviews of a Tigo "maximizer" from 2010-2011 hardly seems relevant to what the TS-4 system might or might not be able to do for me today. It seems like they need more people to give them a try, build the publicity and then I'd be willing to consider them. Maybe the SMA investment will help foster that growth. Right now though, I'm not anxious to be one of the first folks on the wave...

[pclausen]

Thank you for that info. I'm rigging my house up w/ Ubiquiti APs, and I have my eye on one of their 10GbE switches for the future, but I had no idea they were in the solar business. The issue I see here is that their microinverters are only 250W, and I'm planning on 320W panels. That's too much oversizing factor IMHO, even though I fully understand the concept of "right sizing" and the panels not putting out their nameplate ratings. I might ask the installer if he's ever heard of it, just for fun, but I wouldn't him to switch over to it. Thanks though for sharing an alternative to Enphase!

Yeah, I do wish they had larger inverters and panels. That might come with their 2nd generation gear. But yes, if you are limited on roof real estate for getting to the power level you want, then yes, more powerful panels is the way to go.

Funny you should mention their 10GbE switches. I'm in their beta program and picked one up for $299!



I have quite a bit of their gear, and I too, was surprised to discover their did solar as well.



I'm very impressed with their new Mesh APs as well. Amazing speed and range. Anyway, sorry for drifting OT.

[pclausen]

With any system that puts electronics under each PV panel, think about what you are going to do some day when they start failing one by one....

That is my one concern with my 56 roof mount panels. I had 2 DOAs out of 80 inveters. As luck would have it, one was in the top row and the other in the bottom row, but I'm sure the day will come when I need to deal with an inverter in one of the 2 middle rows. It's a non issue for my ground mount array.

[ButchDeal]

All I can really say about this was that it was not my design, but I think I'm happy enough with it? Initially I had asked for Enphase, and when we changed to SE the original proposal was for 57x SolarWorld 300W panels with 3x SE5000A inverters. I wrote the installer back and asked why he would go with 3x 5kW inverters instead of two of the 7600W. My argument was that it would be cheaper to go with 2x 7600's, plus I had some concerns about how he might decide to configure the strings across three inverters, since we haven't really talked about that level of "back-end" detail yet. I didn't get an exact response to my question, because before he was really forced to answer it we ended up upgrading the proposal to the 320W panels, along with him bumping the inverters up to 3x 6kW. I decided not to ask him again about the 2x 7600W, since that would be 18.24kW DC going into 15.2 kW AC, or about 20% oversizing. Not that there's anything "wrong" with that, but if he wants to do 3 inverters, and the price seems right, should I really make a bigger deal about it? Would I be that much better off with one 10-11kW and one 5-6kW (~$3100?) instead of the 3x 6kWs (~$3600?)? Lets assume he isn't willing to alter the price of the job either way, would you still recommend doing it with the two inverters just to have less chance of inverter failure? I'm sure I could convince him to do it that way if it's worthwhile and let him pocket a little extra profit...

Thank you for sharing your experience with Tigo as well!

your installer needs to think of using LARGER inverters. There is no reason for using so many smaller ones. it will be cheaper, and more efficient with the larger inverter able to start up and operate at capacity much better than a bunch of little ones and the array all broken up.
plus less parts on the wall, less to monitor, etc.

as for the strings across multiple faces, doesn't matter. In fact the larger inverter will work better with modules on multiple faces so one string on east, one on south, one on west works great.
skip the 10kw inverter and go with the 11.4kw (very close in price anyway).
put most of the load on the 11.4 and it will hum along all day.
Two inverters are cheaper than 3, less install cost as well and less breakers, wires, monitoring interfaces...

[Magius]

your installer needs to think of using LARGER inverters. <...lots of great info...> Two inverters are cheaper than 3, less install cost as well and less breakers, wires, monitoring interfaces...

Yeah it does sound like a much better solution to get down to 2 inverters rather than 3. That's why I asked him before about going with 2x 7.6kW's vs. 3x5kWs. Once he stepped it up to 3x6kW's I hadn't really considered using inverters of different sizes until you mentioned it. Maybe that's the issue, the installer didn't think of mixing sizes either..? I'm going to talk to the installer about this and see if he'd be willing to go that route, maybe chop a few hundred off the cost even. He should be able to save ~$500 on the inverter cost alone, plus whatever savings in misc parts and labor. I'm not trying to squeeze every drop of profit out of him, but if I propose a design change that can save him money, I don't see why I shouldn't see a bit of a return on that Thanks again!

Funny you should mention their 10GbE switches. I'm in their beta program and picked one up for $299!

Yes I missed out on the beta program deal, they had already raised it to $599 or else I was planning to buy one. A few people took advantage of a glitch and snagged some for $0 from what I saw. I'm not sure how that worked, but I wish they'd extended the $299 pricing instead of honoring the $0 glitch orders... Speaking of, I know for sure I've seen your name around. It must be from over at the STH forums? Or if not that, the FreeNAS forums?

[Magius]

With any system that puts electronics under each PV panel, think about what you are going to do some day when they start failing one by one....

I agree with the general guidance that most people should stick with a string inverter unless there's a good reason, shade etc. to do something different. I'm not an expert by any means, but my interpretation of my roof layout is that a couple string inverters wouldn't be ideal due to the small numbers of panels spread all over the place. I have a two-story "main house" connected to a two-story garage w/ apartment by a one-story covered lanai. So on top of the main house, I'll be installing 21 panels facing east, 10 facing west, and 6 facing south. Then on top of the garage I'll be installing 6 facing east, and 7 each facing west and south. To make things slightly more interesting, the main house roof is on a 6:12 slope and the garage roof I think is 4:12. I'm sure a good installer could come up with a good string arrangement that would balance out all these groups with their different productions across a couple string inverters, but as a layman it seems so much simpler to just stick a module under each panel and know that they're going to work semi-optimally.

Down the road, there will probably be a handful of optimizer failures. I'm not sure that I really have a plan for what to do about it, other than maybe handle them 2 at a time. First optimizer dies, as long as the string is still producing, do nothing. Second optimizer dies, put in a warranty claim w/ SE and pay for the truck roll to fix them both. Maybe other folks have a better idea?

[pclausen]

Yes I missed out on the beta program deal, they had already raised it to $599 or else I was planning to buy one. A few people took advantage of a glitch and snagged some for $0 from what I saw. I'm not sure how that worked, but I wish they'd extended the $299 pricing instead of honoring the $0 glitch orders... Speaking of, I know for sure I've seen your name around. It must be from over at the STH forums? Or if not that, the FreeNAS forums?

The day after I snagged one for $299, I saw the $0 price. Almost ordered a 2nd one for $0, but figured they would catch and I'd have to pay the $299 price. Don't really need 2 of those, at least not anytime soon. Probably saw my name on the FreeNAS forum.

[Magius]

Two inverters are cheaper than 3, less install cost as well and less breakers, wires, monitoring interfaces...

I just wanted to follow up and say that I presented some of your arguments to my installer along with some of my own, and he agreed to go with a two inverter solution. We haven't discussed the specifics yet, it should be an 11.4kW paired with either a 6kW or 7.6kW (probably the former). He's working up a new proposal/contract and hopefully by the end of the week I'll be signed up.

His initial rationale was that he divided my home into three "zones" and was pairing one inverter with each zone. Presented with my (and Bruce's) arguments for the benefits of eliminating an inverter, he re-ran the numbers and agreed that using just two would be fine. He did tell me that as far as the module to string and string to inverter assignments, that all gets done by the engineer, so I'll have to take a look at that design later when its complete.

He didn't mention giving me any kind of a credit back on the system price, so odds are this change will just bring him a little extra profit... That said I'm happy with the price I've negotiated, and at this point trying to squeeze him by asking for say $250 back seems like bad sportsmanship, lol.