96-cell modules worth higher cost to get more power at low irradiance levels?

[jflorey2]

SOME optmizers are used with string inverters.

SolarEdge has an optimized system. The inverter is not a string inverter in the since that it does NOT have MPPT and does not have the ability to string modules and operate without the optimizers.

It is very much a string inverter in that panels are arranged in long strings, and the power inversion takes place at a central location where all those strings come together. Agreed that the MPPT happens in a distributed fashion, though.

That just one aspect of the panasonic HIT modules, they are high efficiency modules. The main reason to use them is to fit more kW in a smaller space. With SolarEdge the actual cell count matters little (other than using appropriate optimizers for the higher voltages).

Agreed there. Efficiency is a big deal on small installs where the user wants as high a generation as possible.

[ButchDeal]

It is very much a string inverter in that panels are arranged in long strings, and the power inversion takes place at a central location where all those strings come together. Agreed that the MPPT happens in a distributed fashion, though.

they can not be used WITHOUT the optimizers though. It is more of a hybrid between the micros with distributed MPPT as well as inverter vs string inverters which have centralized MPPT as well as inverter.
SolarEdge has distributed MPPT but central inverter.

Other optimizers are tack on to string inverters

[JSchnee21]

I recently went though a similar decision making process regarding 60-cell vs. 72-cell vs 96-cell for my residential install. I went through EnergySage and identified a great local (NJ) installer whom I have been working with. Their first quote was great (IMHO) at $2.92/Watt (pre-federal tax deduction) complete for 35 72-cell 365W panels (12.78kW) and SolarEdge 11.4kW inverter with P400 optimizers. Aside from a fantastic salesperson, the other component that sealed the deal for me was that we needed a new roof and this vendor, together with their roofing partner, were able to replace my roof and skylights at the same time and bundle the site prep costs.

But, when it actually came time for measurements, the shape of my roof was such that the 72-cell panels didn't fit well. So either I would have to accept a smaller array (~11kW) or I needed to switch to either 60-cell (LG 320W) or 96-cell (Panasonic HIT 330W). I wanted to maximize my SREC production (and offset 100% of my usage) so I wanted to install as large of an array as possible.

I went back and forth for a while between between the LG's and Panasonics (37 total panels would fit). Obviously, based on the nameplate rating, their modeled yields would be very, very similar. In the end I chose the Panasonics (Sanyo) for a number of reasons:

1) Marginal price increase -- $1900 more than original quote for LG 72-cell 365W's. New Panasonic array would be $0.29 more per Watt) $3.21 per Watt pre-federal tax rebate, and slightly smaller (12.21kW)
2) Panasonics now have 25-yr MFG warranty on materials and workmanship much better than 10 or 12 for LG
3) Panasonics now have 25-yr power output warranty (1st year 97%, after 2nd year 0.26% annual degradation to year 25 -- which is 90.76% of original)
4) Panasonic's PTC rating (311.3W) as a percentage of name plate was much better than LG and many others
5) More than a decade of real world data and accelerated reliability testing from Fraunhoffer and others. Obviously Kyocera and SunPower are better, but reliability and durability of the Panasonic panels looks very, very good
6) Outstanding Temperature Coefficient (0.258% Pmax per degree C)
7) Multiple systems in the field with real world data showing little or no annual degradation in power output over a decade or longer
8) Certified not to exhibit LID or PID degradation by multiple independent testing agencies
9) Aesthetics. While they do have white back sheets, because of the black frames and large silicon surface area they look almost as good (to me) as all black panels, without the higher price and poor temperature coefficient.
10) Strength of Panasonic name, reputation, an experience manufacturing solar panels (Sanyo really)
11) Ongoing partnerships with Tesla, Toyota, others.

Don't get me wrong, I think LG's are also very good, and space efficient panels. But for me, Panasonic had the edge, despite a small price increase. If space was not a concern, a less expensive, less efficient panel could have been fine, too. Unfortunately my roof angle is 20 degrees, though I am almost due South (175). So I'm hopeful the AR coating and "better sensitivity" (likely hogwash) will help boost my early morning and evening production.

Waiting anxiously for my system to be interconnected and turned on!
Jonathan

[bcroe]

3) Panasonics now have 25-yr power output warranty (1st year 97%,
after 2nd year 0.26% annual degradation to year 25 -- which is 90.76% of original) Jonathan

I believe that degradation more than the apparent guesses seen in the past. I calculate 93.76% output
at 25 years, assuming against the original (not compounded). Bruce Roe

[JSchnee21]

I'm not sure how they are calculating it, but the spec sheet (ftp://ftp.panasonic.com/solar/specsh...spec-sheet.pdf) shows the 90.76% value on the graph. If you look at some of their sales literature and other published reports from Europe and Asia, Panasonic shows system outputs for 10 and 15 yrs across 10 or more systems (obviously cherry picked) with no apparent degradation at all.

Of course, no sooner did I post this (and my panels were installed) did I see the specs on LG's new Neon R series, 30 strand busbar. Higher wattage 60-cell, warranties to match Panasonic (for the most part). I'm not sure if these are pseudo bi-facial or not. Also not sure if these are "really available" yet or what the cost per watt will be.

http://www.lg.com/us/business/solar-panel/all-products/lg-LG360Q1C-A5

In the US, Panasonic has a very small Solar panel market share compared to the rest of the world. In contrast LG is a huge player here in the US. Oh well, time to start researching for the next house (-:

[sensij]

There are some very old systems on PVOutput.org, you may find better data there regarding real world aging that what you get from marketing materials. Panasonic HIT modules weren't added to the CEC database until 2013, so at best, you are looking at only 4-5 years of real world data. I'd be skeptical of material claiming 10 years of true field experience.

[J.P.M.]

I believe that degradation more than the apparent guesses seen in the past. I calculate 93.76% output
at 25 years, assuming against the original (not compounded). Bruce Roe

I think most outfits use a linear model based on degradation of a constant per yr. %age of the original performance.

[brucet9]

3) Panasonics now have 25-yr power output warranty (1st year 97%, after 2nd year 0.26% annual degradation to year 25 -- which is 90.76% of original)

8) Certified not to exhibit LID or PID degradation by multiple independent testing agencies

Jonathan

These two points are apparently contradictory. With no LID, there would not be 3% degradation in the first year. Panasonic explained that to me by saying the STC measurement has a + - 3% margin of error, so the warranty says 97% first year even though there is no LID.

LG brags that they have found a way to limit LID to 2%, which for non "n" type cells is very good.

[JSchnee21]

Sorry, I was perhaps a little too free and loose with the English language when I said there was no LID. Perhaps I should have said that their LID is significantly reduced compared to many conventional silicon wafer designs. All of my panels ranged from approx ~331-333W according to their STC testing stickers -- so only about +1% at best. Not to pick nits, but with a warranted output (potential) >=97% of STC in year 1, Panasonic must be pretty confident that the combination of +1 to +3% at delivery, and less than 3% LID (combined with their +/-3% STC testing variance) will likely preclude them from any potential warranty claims. From my ignorant, novice perspective the infant LID is pretty much a wash. Obviously the projected annual degradation of 0.26% is potentially far more significant. With regard to PID, I would suspect that SolarEdge systems are largely/entirely resistant to PID in general given that the maximum voltage any one panel ever sees is its own Vmax (aka 30-60V) versus the conventional 600V or more.

With regard to Neon R, I haven't found them for sale in the US yet, but from some of the news reports on them from Australia, and sporadic pricing in Euros, it sounds like LG is gunning to be more expensive than SunPower! The Neon R's are a whole new design (wafer, 30 strand rear bus bar, new warranty scheme, etc.). They're going to want to recoup the R&D costs for the first several years. But given a few years, it wouldn't surprise me if these are the same or cheaper than the Pansonic panels. Regrettably, Panasonic hasn't done very much with the Sanyo product in nearly a decade (save for incremental efficiency and Pmax increases). The pace of innovation in LG solar panels is pretty remarkable.

Unfortunately, with the race to the bottom on solar pricing in general, and especially if the currently political powers that be bork the Federal solar tax rebate in the coming years, or start widespread limits/revocations on net metering, and/or SRECs's, the whole bottom will fall out of the industry. Without these incentives, very few will invest in solar if it has a 10-15 (or longer) ROI time horizon. I'm crossing my fingers that I break even in 6 and that's only if NJ's SREC's stay at or above $200.

Hopefully Panasonic will catch on in the US and give LG and SunPower a run for their money. I had high hopes for SolarWorld with their PERC cells, but alas the market and cheap Chinese dumping has all but done them in.

[brucet9]

Sorry, I was perhaps a little too free and loose with the English language when I said there was no LID. Perhaps I should have said that their LID is significantly reduced compared to many conventional silicon wafer designs. .

Thanks for the information and insight.

Your statement, however, was not far from correct. From an email I received from Panasonic about a week ago:

"PTC is measured before LID (light induced degradation = boron-oxygen reaction ) happens which is normally after 40hours of sun at 1000w/m2. Our panels do not have boron (our cells are n-type) so we have an extremely low LID, 0.5% in the worst case scenario -please see attached third party testing. Why do we offer 97%? because flash test measuring machines have a +-3% tolerance "
In the attached test results run by DNV-GL, of 20 panels tested, after 40 hours at 1kW/sq meter, the average LID was 0.29%; lowest 0.03%, highest 0.72%; three results <0.09% two >0.50%.

SunPower n-type panels (E20 and X21) specs claim a 50% higher temperature coefficient (0.38%) and very slightly lower annual degradation than Panasonic HIT.

I too was sorry to see Solar World in trouble, but it seems that many companies are struggling to compete against Cheap Chinese panels. SunPower revenues are rising even as losses mount, although I have read that much of that is from plant shutdown charges and that they should turn profits again by 2019. I can't find anything on Panasonic financials, since PV is just a small part of the corporate whole.

What companies do you see as strong enough to weather the storms?

[solar pete]

What companies do you see as strong enough to weather the storms?

Chinese ones, or those who manufacture where labour is cheap, China, India, etc

[JSchnee21]

For what it's worth, the distributor that delivered my panels had two large pallets of Hanwha Q-Cells on the same trailer. They seem to get a lot of mentions around the interwebs, as do Canadian Solar. I haven't looked into the financial health of either.

IMHO, I'm not sure Panasonic solar is headed in the right direction with regard to manufacturing cost containment. My panels were made at their relatively recent Malaysian facility which, after it opened, led to the shuttering of the Japanese Sanyo manufacturing facility (obviously lower labor costs) and, at the time, sinking demand in the Japanese market.

But, Panasonic just announced this year that they are re-opening the Japanese plant, and investing substantially in a new US facility in Buffalo, NY with Tesla. They've really ramped up promotion and installer partnerships in the US. But, I'm not sure such promotion can match the planned growth in MFG capacity. The labor costs in Japan and the US are going to be very high -- though the lines are highly automated.

While I'm a big fan of Tesla cars, I'm not sure their Solar Shingle idea will really catch on (which is one of the reasons for Panasonic's planned capacity growth). They look nice, but are way too expensive, and I've not seen any very substantial information with regard to how their solar shingle KWh yields per square foot/meter compares to conventional 17-20% efficient panels. Aka what's the price per watt, and can you put enough solar shingles on a roof to be useful?

Now that Tesla owns SolarCity again, Musk might force them to use Panasonic panels given his extensive partnership with them for batteries and solar cells, but SolarCity's annual installations has been shrinking as of late. Musk and Panasonic are talking about this Buffalo plant having over a GW of MFG capacity by 2019 or so.

http://buffalonews.com/2017/03/07/robinson-panasonics-role-reflects-deep-changes-solarcitys-buffalo-factory/