Comparison of Panasonic, SunPower and LG

[wildta]

I came across this Texas installer's comparison of several popular panels side by side using DC Optimizers. Scroll to the table near the bottom. It's a really great comparison because the data is taken from the same day on the same roof.

https://www.hesolarllc.com/panasonic-vs-sunpower-vs-lg/

Was leaning towards SunPower but after reading this comparison, Panasonic is the best choice without a question.

[J.P.M.]

At $3.00/ STC W, the Panasonic does seem to have an advantage. Still, The value of this comparison to me looks like the pretty much singular non cost effectiveness of the Sunpower offering as well as the smaller differences among the other offerings. That is, panels are a commodity with Sunpower being the least cost effective. Local markets and conditions and application parameters like roof access/pitch/type and other things can also affect pricing as can some developed negotiating skills on both sides. I'd be careful about applying the pricing to other markets although the relative prices one panel to another might be valid in different markets.

Overall, probably another good set of info even though it's a bit anecdotal in nature.

[JSchnee21]

I'm not sure what happened with that site (too much traffic / too many re-directs) but I ran across it a year or so ago. It's a good site, though it seems to smell a bit of an installer who just partnered with Panasonic and is now looking to promote their product. Disclaimer -- I have Panasonic panels myself.

What I cannot understand in today's age of rampant product reviews (most of which are crap). Why are there no independent testing agencies or even consumer reports, etc. comparing solar panels, inverters, etc.

Yes, there is the Fraunhofer.
(www).ise.fraunhofer.de/content/dam/ise/de/documents/publications/studies/Photovoltaics-Report.pdf
(www).ise.fraunhofer.de/content/dam/ise/en/documents/publications/studies/recent-facts-about-photovoltaics-in-germany.pdf

But their panel level performance and quality reports are not free, and manufacturer names are blinded to 3rd parties.

I assume this is because of the capital investment cost, the difficulty of designing a scientifically rigorous study, the long time horizons, and the small differences between solutions.

But from my perspective there are many relatively simple questions:

1) Whose AR coating is most effective at different angles of illumination?
2) Whose AR coating is the most durable over time
3) Whose panels perform best under diffuse or filtered conditions (haze, diffuse clouds, smoke)
4 Whose panels perform best under shallow/steep/oblique angles. whose panels perform best in the mornings and evenings?
5) Whose panels are most efficient at capturing natural daylight -- not test lamp light
6) Whose panels have the lowest internal resistence
7) Are there any real advantages/disadvantages to:
front contact
back contact
Cello
Copper backplane
60, 72, 96-cell
white backsheet, black backsheet, clear backsheet, etc.
SolarEdge vs. Enphase vs. Fronius/ABB/etc.

Sure, many of these questions seem trivial and obvious. But there's little or no quantitative,semi-quantitative, or even useful anecdotal data on many of these points.

Given the multi-million cost of large commercial solar fields, even small differences in productivity and their relationship to per panel cost, would have a huge impact on ROI.

[J.P.M.]

I'm not sure what happened with that site (too much traffic / too many re-directs) but I ran across it a year or so ago. It's a good site, though it seems to smell a bit of an installer who just partnered with Panasonic and is now looking to promote their product. Disclaimer -- I have Panasonic panels myself.

What I cannot understand in today's age of rampant product reviews (most of which are crap). Why are there no independent testing agencies or even consumer reports, etc. comparing solar panels, inverters, etc.

Yes, there is the Fraunhofer.
(www).ise.fraunhofer.de/content/dam/ise/de/documents/publications/studies/Photovoltaics-Report.pdf
(www).ise.fraunhofer.de/content/dam/ise/en/documents/publications/studies/recent-facts-about-photovoltaics-in-germany.pdf

But their panel level performance and quality reports are not free, and manufacturer names are blinded to 3rd parties.

I assume this is because of the capital investment cost, the difficulty of designing a scientifically rigorous study, the long time horizons, and the small differences between solutions.

But from my perspective there are many relatively simple questions:

1) Whose AR coating is most effective at different angles of illumination?
2) Whose AR coating is the most durable over time
3) Whose panels perform best under diffuse or filtered conditions (haze, diffuse clouds, smoke)
4 Whose panels perform best under shallow/steep/oblique angles. whose panels perform best in the mornings and evenings?
5) Whose panels are most efficient at capturing natural daylight -- not test lamp light
6) Whose panels have the lowest internal resistence
7) Are there any real advantages/disadvantages to:
front contact
back contact
Cello
Copper backplane
60, 72, 96-cell
white backsheet, black backsheet, clear backsheet, etc.
SolarEdge vs. Enphase vs. Fronius/ABB/etc.

Sure, many of these questions seem trivial and obvious. But there's little or no quantitative,semi-quantitative, or even useful anecdotal data on many of these points.

Given the multi-million cost of large commercial solar fields, even small differences in productivity and their relationship to per panel cost, would have a huge impact on ROI.

Mostly agree. On the questions you pose, a lot of such information is reported in the journals such as "Solar Energy", "Journal of Applied Physics", or the engineering journals etc, and has been for some time. However, a lot of the information on practical methods is still of an unresolved nature - at least unresolved enough so that discussion continues. Hence, the stuff of white collar welfare, and more than a few mostly useless master's theses that rehash the same information and add little to the body of knowledge.

One example: At this time ARC tech./science is at a point where the best improvement in reduction of reflection loss over the solar spectrum useful for silicon devices (that is, for wavelengths < 1.15 micrometers) is obtained in one of two ways. One, by applying a film with low refractive index using vac. deposition or nanotechnology or other means at an optical thickness of pi/4 of the of the dominant wavelength. The incoming and reflected wavelengths have a phase difference of pi and cancel. The other is to apply one (or more) coatings using similar methods at a refractive index that is the geometric mean between the medium (usually air) and the glazing (usually glass). That lowers the refractive index of the glazing system (the 2 layers) with reflection and hence reflection losses reduced and that can be calc'ed and an integrated value over wavelengths and angles of incidence can be obtained. Most of the literature (and research by companies) is currently about finding the most cost effective way to produce a durable and effective coating using the second method.

The methods principles are well understood. It's now mostly an application/production and durability situation.

Also, as you write some questions are trivial and amount to skunk spoor. But those are the types of questions that marketing slugs love to use to prey on solar ignorance and increase profits. IMO, the cons and deception and how to effectively call them out are what needs to be addressed. But that's always been the case.

[eric-hoff]

Hi, I saw a link to our test array posted here and wanted to provide a little insight.

For the first few years we kept nearly all data private and used the data internally when deciding what panels we wanted to add to our product line. So the comment above that the page is anecdotal is fair because at the surface level we were really just showing consumers what we (as a company) do on our end to choose a panel.

However, we have been making a lot of updates over the past few weeks that just went live:
-Panel Addition: QCells 325W Qpeak Duo
-Panel Addition: Solaria 340 and 350W
-Panel Addition: LG NeON2 335W
- Added Cost / kWh ranking: This uses actual kWh data from the HESOLAR test array compared to our pricing for the panels and ranks them in a spreadsheet using standard deviation.
- Added kWh / sqft ranking (Efficiency): This uses kWh data to quantify efficiency. Before we just listed them according to their data sheets efficiency rating.
- Added kWh / Watt (nameplate) ranking: This quantifies performance against the solar panels advertised wattage and also uses recorded data from our test array.
- Removed subjective text about Panasonic being the winner:When we first built the test array in early 2017 we were getting Panasonic at a great price point and it was the clear winner. An update was long overdue and we don't want to devalue our research here by picking a favorite.

I hope the information above and the updated page (https://www.hesolarllc.com/panasonic-vs-sunpower-vs-lg/) helps future solar customers decide which panel is right for them. I urge you to put more value in the companies design and installation team, opposed to specified material.

[JSchnee21]

Hi Eric,

Welcome! Thanks so much for joining. I will definitely check this out. I think you will find this board is a lot of fun. There are a number of installers, several enthusiasts, and lots of new folks just trying to get started with the "hobby."

Just a word of caution as one friend to another. We don't try to sell anything here and shills are very quickly run out of town. I'm sure you wouldn't do that, but the moderators (which I am not) are pretty aggressive (as they should be). That said, many of us do try to make practical recommendations about system designs, reliable hardware solutions (from our collective experiences), the pros and cons of different products, and when asked, recommendations for reputable local vendors to new members who are often overwhelmed just trying to get started.

The solar community is definitely in need or more real world data from folks like yourself to help us make pragmatic cost effective decisions. Many of us maintain accounts on PVOutput.org as well, and have configured our inverters to post system data there in real time for extended graphing and reporting.

For example my system:
pvoutput.org/list.jsp?userid=58372

If you're not familiar with the site, do check it out.

All the best,
Jonathan

[TampaSpecialist]

As an installer, I don't see the advantage of any of the manufacturers listed in this thread. IMO it's similar to purchasing a Lexus instead of the equivalent Toyota. The idea behind a majority of installs, is to save money. You can knock thousands of dollars off your install by going with a top manufacturer that doesn't try to sell you on their name. And we have installed both "tiers".

Also, having installed thousands of panels, I've never had one of my panels go bad, or have any warranty issues at all. Just some food for thought.

[J.P.M.]

As an installer, I don't see the advantage of any of the manufacturers listed in this thread. IMO it's similar to purchasing a Lexus instead of the equivalent Toyota. The idea behind a majority of installs, is to save money. You can knock thousands of dollars off your install by going with a top manufacturer that doesn't try to sell you on their name. And we have installed both "tiers".

Also, having installed thousands of panels, I've never had one of my panels go bad, or have any warranty issues at all. Just some food for thought.

Welcome to the neighborhood.

You're experiential knowledge is further confirmation of what most of the informed folks around here have been saying for quite some time now.

- Panels have become pretty much a commodity beyond some basic quality level.
- Most residential grid tie systems are done because of the perception that doing so will save money by reducing an electric bill, although often the PV addition is more long run expensive than doing nothing, but most folks can't be disabused of the notion that PV is a slam dunk panacea.

I'd add considering use reduction before considering PV, staying with local vendors if PV is the choice, and spending as much time evaluating those local vendors as on equipment selection, and almost never lease or do a PPA might be some other things, among many, to consider.

[malba2366]

Welcome to the neighborhood.

You're experiential knowledge is further confirmation of what most of the informed folks around here have been saying for quite some time now.

- Panels have become pretty much a commodity beyond some basic quality level.
- Most residential grid tie systems are done because of the perception that doing so will save money by reducing an electric bill, although often the PV addition is more long run expensive than doing nothing, but most folks can't be disabused of the notion that PV is a slam dunk panacea.

I'd add considering use reduction before considering PV, staying with local vendors if PV is the choice, and spending as much time evaluating those local vendors as on equipment selection, and almost never lease or do a PPA might be some other things, among many, to consider.

Why do you say that most systems don't save the owner money? I would figure most people would come out ahead after the tax credits and state incentives that are available. My personal calculation comes out with a 8 year payback and a 12.3% cash on cash ROI.

[funguy11]

Why do you say that most systems don't save the owner money? I would figure most people would come out ahead after the tax credits and state incentives that are available. My personal calculation comes out with a 8 year payback and a 12.3% cash on cash ROI.

JPM is biased against solar for some reason. Most people do save money.

[JSchnee21]

Well, just being pragmatic, I'd hazard a guess that JPM might actually be right. Unless you live in California or Hawaii with sky high TOU pricing, or perhaps DC, MA, or NJ high SREC values I would not be surprised if most/many folks never actually break even.

In my own case in NJ, with decent SREC's (~$200/MWh) and Net Metering, I'm looking at a 7 or 8 year to break even. I paid "cash" (low interest loan from my 401K) and am now 2 years in. Electric rates in NJ are low (~$0.12 to $0.14 per kWh). So even though I use a lot, and have a large array (12.2kW DC STC) I only earn ~$4500 per year from SREC's and consumption offset cost of the system (after the Federal tax rebate).

Given that most people, on average, move in 5 to 10 years, most folks will only just have broken even around the time they move. If you lived in a state with no SRECs or Net Metering your time to break even is going to be even longer. And then if you're some poor schmuck with a tiny 3kW to 7.6kW system and a big box lease or PPA, you're completely screwed.

It's like the old adage:
"Honey, look at how much money I saved. XYZ was having a sale."
Of course, not buying the item at all would have saved even more money (-:

JPM is right, there is nothing more cost effective than saving/using less energy. That said big ticket energy efficiency upgrades (HVAC) have similar challenges breaking even. Simple, small, inexpensive things are best -- insulation, air sealing, caulk, opening windows, sun shades, etc. Just home improvements and resale value.

[funguy11]

Well, just being pragmatic, I'd hazard a guess that JPM might actually be right. Unless you live in California or Hawaii with sky high TOU pricing, or perhaps DC, MA, or NJ high SREC values I would not be surprised if most/many folks never actually break even.

In my own case in NJ, with decent SREC's (~$200/MWh) and Net Metering, I'm looking at a 7 or 8 year to break even. I paid "cash" (low interest loan from my 401K) and am now 2 years in. Electric rates in NJ are low (~$0.12 to $0.14 per kWh). So even though I use a lot, and have a large array (12.2kW DC STC) I only earn ~$4500 per year from SREC's and consumption offset cost of the system (after the Federal tax rebate).

Given that most people, on average, move in 5 to 10 years, most folks will only just have broken even around the time they move. If you lived in a state with no SRECs or Net Metering your time to break even is going to be even longer. And then if you're some poor schmuck with a tiny 3kW to 7.6kW system and a big box lease or PPA, you're completely screwed.

It's like the old adage:
"Honey, look at how much money I saved. XYZ was having a sale."
Of course, not buying the item at all would have saved even more money (-:

JPM is right, there is nothing more cost effective than saving/using less energy. That said big ticket energy efficiency upgrades (HVAC) have similar challenges breaking even. Simple, small, inexpensive things are best -- insulation, air sealing, caulk, opening windows, sun shades, etc. Just home improvements and resale value.

Homes with solar sell for 4% more on average so not calculating in this amount when you say "Given that most people, on average, move in 5 to 10 years, most folks will only just have broken even around the time they move.". Obviously, people are going to pay for a house where their monthly utility bill is less.

[SunEagle]

JPM is biased against solar for some reason. Most people do save money.

Well "saving money" can be debatetable. Most States do not have any solar incentives or SREC's to help reduce the cost. And even with the Fed tax credit and full Net Metering I have calculated that it would take me at least 10 years to payback a 6kw system with an installed cost of $1.80/watt. Which is below all of the prices I have received even going with more wattage.

Most of my issue for not jumping into solar is because my POCO only charges me about 12 cents/kWh and I pay less than $200 per month on average.

Until I can get the cost down to $1/watt installed my money is better left in my IRA or finding ways to reduce my electric usage then investing in solar.

[SunEagle]

..... Obviously, people are going to pay for a house where their monthly utility bill is less.

Again maybe in some states. But most real estate brokers here in FL feel that solar is not a reason for a price increase of a home. It actually may drive people away from looking at it.

[funguy11]

But most real estate brokers here in FL feel that solar is not a reason for a price increase of a home. It actually may drive people away from looking at it.

Not true.