LG300N1T-G4 -- T for Transparent?

[J.P.M.]

I see what he is saying, but to reject an improvement in tech is very closed minded. I see that type of thinking a lot in here. The only BS I see here is J.P.M.'s comment. There are a lot of applications. No matter how the past modules were marketed. Look at the LA convention center with all of the unisolar arrays mounted on a bright as hell white roof. (over 6000 laminates when I was there testing them) Using these modules on tilts would reduce the amount of space needed for the inverters on that flat roof. I have worked on that roof for unisolar to determine why the initial install was not performing. You go blind up there without eye protection and it would be a perfect solution.

To be clear, I'm in no way rejecting improvements in product quality and innovation. A pretty good portion of my engineering career was involved in such things.

My issue is with what I see as somewhat deceptive marketing to gain an advantage, perhaps an advantage in public perception only in that folks will see or imagine superior performance where it may come only at the expense of off-standard application and construction requirements. It's using people's solar ignorance in an attempt to gain any such marketing advantage that such ignorance can enable.

Bifacial's a good idea - if for no more cost, so much the better. But it better be little or no cost if it's being marketed to the solar ignorant, because that's what the enhancement will amount to for most any common residential application most of those folks are probably, in their ignorance, assuming.

Question: Are the panels on the LA convention center horizontal or tilted ? I suppose I could look it up. I ask that you indulge my laziness.

[ncs55]

Obviously more people realize this than you think, You need to stop and get off of your white horse and quit putting people down. No one here said that they would gain anything crammed close to a roof. You need to stop and stop now.

[DanKegel]

Sure, shady characters abound. But that's what reference checking and good sense are about.

Let's put it this way: LG's bifacial panels are likely to be a useful tool, in the same way a gun is. Should Smith and Wesson be considered evil just because some resellers are acting immorally?

[J.P.M.]

J.P.M. is assuming the worst way the panel could be marketed is how it will actually be marketed.

There's some precedent for this -- see the awful HyperX marketing -- but he's jumping the gun here, I think.

Having been a peddler paid on commission for the first 10 or so years of my working career, I may just have a slightly more realistic opinion than some about why and how things are marketed, and what motivates people to do things. I don't like all - probly a lot - of the ways the game is run, but I don't get much say in that. I deal with it like I find it and see it.

if someone thinks companies are in this for honesty and altruism, or that people can't be manipulated, or someone doesn't understand the temptation to shade reality, they are, IMO only, naïve and a sitting duck.

[ncs55]

J.P.M. C'mon man, don't be so pessimistic about this. I have not seen LG claim anything except what is on the spec sheet. So what adverts are you referring to? I also would not consider a large commercial array on a white roof or ground mount as non standard applications either. Most consumers may be clueless, obviously in your area, and it is up to us as installers to set them straight. Some installers will pitch this and get bit in the ass very quickly as we have seen in the past. And what exactly are WE assuming anyway? I think it is you that is doing the assuming here. Have some faith that most of us learned from the past claims and mistakes. I don't know where you live but the people in SD are not as stupid as you are saying. And most folks are educating themselves before going solar. Just like the people that browse this blog looking for answers, so stop degrading them by calling them clueless. Can you please be a little more positive?

[DanKegel]

How much irradiance do you think the underside of an array parallel to and 6 " off a roof gets ? A clue: not much.

Right. Who's advocating installing the LG panels that way? LG certainly isn't; their video https://www.youtube.com/watch?v=uzpmRKLdPrU shows how to do it right.

[DanKegel]

Awesome details, thanks. And did they get the cleaners to be more gentle? (Come to think of it, do you have data showing that cleaning is more helpful than harmful?)

[DanKegel]

Well, bifacial panels are a different beast, of course it's going they'll need to be installed a little differently.
Vendors differ in how well they communicate the difference.
The best so far is Prism Solar, whose design guide http://www.prismsolar.com/pdf/Design_guide.pdf
is backed up by serious data, http://ieeexplore.ieee.org/stamp/sta...number=7387697
But LG has a youtube video, https://www.youtube.com/watch?v=uzpmRKLdPrU
which does try to get the point across -- mount it higher, above a bright surface, for best results.

Installers are, in my sample size of one, completely unprepared for this.
I expect after a few successful installs show how to do it right, and get written up in industry rags with sufficient detail, they'll start getting the idea.

[J.P.M.]

The datasheet says the backside is about 92.5% as effective as the front side.

92.5% of a small number is a smaller number.

How much irradiance do you think the underside of an array parallel to and 6 " off a roof gets ? A clue: not much.

How many people do you think have a glimmer of a clue that to realize any enhancement at all from the backside of one of these panels, the panels need to be non parallel to their mounting in ways that more than a few people find aesthetically unappealing ?

How many people do you think would buy this product based on claimed enhancement if LG's advertising came with photos showing array tilts or the type and location of reflective surfaces required to get close to the enhancements implied ?

How many people do you think understand the extra costs often and usually involved in what are probably non standard mounting conditions ? Given your recent cluster function experience with tilting a couple of panels, I'd think you'd be mindful of some of the practical problems.

[ncs55]

Are you talking about their current effort, not the old ones on the canopies? I had heard they were spending $6 million on a 2MW array ( http://clkrep.lacity.org/onlinedocs/..._B_4-20-15.pdf ), didn't know it was actually happening.
Yeah, that'd be a perfect place to use bifacials.

Why *wasn't* it performing?

Actually I was talking about the Long Beach Convention center, sorry. I bid a repair about a year after the initial installation of the Unisolar laminates through Unisolar and the convention center, (I was one of the contractors in the SD area that was collecting data for US and doing the repairs that they directed under their warranty.) At the LBC, the production never came close to what was expected right from the start. We checked the inverters and they were fine but noticed low string voltage readings. We tested every string there for performance and while doing this we found that the string wiring #1 and #7 were crossed and the fusing was blown for each, in every combiner. About 20% of the array was not getting power to the inverters. We fixed the wiring / fusing as per US instructions and the production went up to US expected levels. But still a little less power than claimed by the manufacturer. We also found that the module cleaners were using pressure washers to clean the modules and water was pushed into the little junction box where the pos and neg wires come out of the laminates. This caused about 20 or so modules to short out. A few had actually arced from the bottom and cut through the metal substrate that was attached to the roof. It looked like a plasma cutter had been used. We pulled those off of the metal and replaced them as well and it worked fine after that. Although IMO was still a little low in production. It was a simple wiring mix-up in the end that caused the biggest problem. I still have two new laminates left over from that job, lol.

[J.P.M.]

As you know, these panels are for applications where they're mounted well up off a high albedo surface, tilted. For instance, on a flat roof (many of which are very white here in Los Angeles).

I'm not sure why you think they're being pitched for flush mounted applications.

I know that. I also know most folks are clueless about such things. And until LG comes along and says (as you seem to be saying) that somewhat non standard applications and installation techniques are required to obtain some or most of the possible production enhancement claimed, I say the advertising is, if not deceptive, at least disingenuous. . Look, most folks are clueless of what you seem to be assuming. I also know that people see what they want to see and hear what they want to hear. They will see the "up to X % more, and think it applies to all cases, not having a clue that in most every case of most any array they're likely to look at (parallel, and a few inches off a roof) any enhancement is likely to be unmeasureable.

If the price doesn't increase - OK, but the implied possible improvements are, IMO only, overstated, and it seems to me at least partially done with the idea of making it easy for most folks solar ignorance to enable them to think things may be better than they are.

[DanKegel]

Are you talking about their current effort, not the old ones on the canopies? I had heard they were spending $6 million on a 2MW array ( http://clkrep.lacity.org/onlinedocs/..._B_4-20-15.pdf ), didn't know it was actually happening.
Yeah, that'd be a perfect place to use bifacials.

Why *wasn't* it performing?

[ncs55]

J.P.M. is assuming the worst way the panel could be marketed is how it will actually be marketed.

There's some precedent for this -- see the awful HyperX marketing -- but he's jumping the gun here, I think.

I see what he is saying, but to reject an improvement in tech is very closed minded. I see that type of thinking a lot in here. The only BS I see here is J.P.M.'s comment. There are a lot of applications. No matter how the past modules were marketed. Look at the Long Beach Convention Center with all of the unisolar arrays mounted on a bright as hell white roof. (over 6000 laminates when I was there testing them) Using these modules on tilts would reduce the amount of space needed for the inverters on that flat roof. I have worked on that roof for unisolar to determine why the initial install was not performing. You go blind up there without eye protection and it would be a perfect solution.

[DanKegel]

A little harsh?

J.P.M. is assuming the worst way the panel could be marketed is how it will actually be marketed.

There's some precedent for this -- see the awful HyperX marketing -- but he's jumping the gun here, I think.

[Willaby]

I guess in one sense it's good you keep dredging this crap up so those with some modicum of common sense can call B.S. on it, but IMO, when you pull this crap, it's counterproductive to progress in R.E.

A little harsh? ! I mean it's a product of LG, a heavy in the industry. It's not like it's some snake oil you rub on your panels to increase production. Just learning about the technology that if you flip the panel over you still get ~90% production is interesting (like if your incompetent installer mounted it wrong - jk). Seriously, maybe not for 95% of applications, or maybe even 98%, but, yeah, some tilt-up's with the right architecture, I can see it.