How to Pick a Solar Panel Manufacturuer: too many choices!

[j_kraut]

I'm looking to build about a 20kw ground mounted system, and going with bifacial panels. I am fairly new to solar, and when i look at solar retail sites how does someone know which brands are the dependable solar panel brands? Seems like the marketplace is flooded with brands and fewer manufacturers. It's hard to weed through these. Is it best to just trust the specs?

In terms of bifacial, there has been some innovation of late. When there are new innovations in solar, how does a person get the honest reviews on whether its a good idea to trust this new tech or stay with old. Perhaps i'm thinking too hard, but looking for guidance from someone experienced in buying panels.

Finally, is it best to follow price as long as specs check out? For example, i spoke with with an internet retailer of panels and they said they get "special buys" sometimes on panels left over from big installs. Hard to trust that for sure, but wanted to get others approach to this.

Moderator note: Hi j_kraut, welcome to the forum. We usually don't allow links to solar sites, especially with first time posters, but most here are familiar with the various sites available, including those you mentioned, so you should get some good info.

[oregon_phil]

Are you only after solar panel brand information? Since you said you are fairly new to solar, are you open to input to other aspects of your project?

[j_kraut]

Are you only after solar panel brand information? Since you said you are fairly new to solar, are you open to input to other aspects of your project?

I'll take any advice i can get. I do want to mention however, in my design i'm working on, i'm set on bifacial. Brand of panel and even comparing the specs in an intelligent manor would be important. For example, i'm assuing not every panel from a manafactur is "good", they may have some good ones and probably a few bad. I want to avoid to bad.

[bob-n]

In general, solar panels have matured to the point that it is hard to tell one brand from another. They all use cells from major manufacturers, use excellent backing, excellent connectors, and excellent frames. They are all reliable and all wear out at approximately the same rate. They all have warranties, and all make it virtually impossible for the end user to get warranty support.

In specific, however, bifacial panels are comparatively new. There may be differences between manufacturers just due to that. I expect any differences will show up in the simple specifications: power output per panel at STC & cost per panel.

Disclaimer: I've never personally installed a bifacial panel. All of my experience is with single-side panels.

[solarix]

I can get you a great deal on Philidelphia brand bifacial 370w panels from a liquidated Wisconsin solar installer.

In general though, all solar panels are very durable and all have 25 year warranties. The problem is whether the manufacturer is still going to be around for 25 years to support you... You'll pay more for the "tier 1" manufacturers because of that, but all PV panels are amazingly reliable. Its really all about dollars/watt.

[chrisski]

I did not do a project that big, but when looking I checked the output of the panels base off size. There's not a huge difference in the outputs. What I found with that was name brand panels usually passed that test, but generic non-branded panels did not. I'm not sure how this output per square inch method I used would work for bi-facials.

I looked at bi-facials, but for my use on a mobile system, they would not push the extra energy because I could not elevate them the several inches required. I want mine as flush to the vehicle as possible.

[robbyg]

I'll take any advice i can get. I do want to mention however, in my design i'm working on, i'm set on bifacial. Brand of panel and even comparing the specs in an intelligent manor would be important. For example, i'm assuing not every panel from a manafactur is "good", they may have some good ones and probably a few bad. I want to avoid to bad.

The best advice i can give you is to look at some YouTube videos where Bifacial panels are tested against regular Mono Panels.
Your not going to get a lot of extra bang for the buck with Bifacial panels. You will get more power by just using the same amount of money and buying Higher wattage panels that are made by a companies know for high efficiency like Sunpower or LG.

[J.P.M.]

I'll take any advice i can get. I do want to mention however, in my design i'm working on, i'm set on bifacial.

That's the neophyte and wishful thinking in you that makes swallowing the con easy.

Believe what you want but bifacial panels are a gimmick.

Reality: The irradiance the backside of even an equator facing ground mounted panel tilted at local latitude receives is almost all albedo, almost all diffuse and almost all received at low incidence angles - all bad for solar production and resulting in little production when taken together. All those factors make for little irradiance - much less in the real world than the pie in the sky 20 or more % enhancement the hucksters usually/often imply. Without extraordinary measures such claims are B.S. Somewhere between 0 and maybe 5 % on an annual output basis is closer to reality under operational conditions.

If a bifacial panel w/ a 300 STC W front face output can be bought for the same price as a single (front face only) 300 STC W panel, it might be worth consideration. Otherwise it's leaving money on the table.

Spend your time learning about the solar resource and how PV panels work and you'll eventually learn why what I'm writing is reality and why the bifacial hype is a bunch of unsubstantiated horse manure. It's a con.

[heimdm]

Here is the LG bifacial design guide... fairly lengthy.... https://www.lg.com/global/business/d...e_Full_ver.pdf

[bcroe]

Here is the LG bifacial design guide... fairly lengthy....

Lengthy yes. I read between the lines that any advantage is quite small, accidental,
and inconsistent. Bruce Roe

[J.P.M.]

Here is the LG bifacial design guide... fairly lengthy.... https://www.lg.com/global/business/d...e_Full_ver.pdf

Nothing I've not seen before many times and in various iterations, and nothing that would change my opinion about bifacials being mostly an overhyped con that uses consumer ignorance and laziness to enhance the B.S.

If you read all of it and also take the time to really understand how a lot of what's being said is being manipulated and other stuff being entirely left out, you'll be on the way to seeing and understanding why the way bifacials are marketed is mostly a con.

[heimdm]

In the end bifacials from an energy perspective are realistically a couple % points of gain. I think you probably get the most backside energy when the ground is snow covered. Outside of that, like J.P.M. and others have said, you don't get that additional energy. Bifacials with the glass on glass or transparent backsheet does provide a different visual appearance. Any backside gain is purely bonus, and should not be counted on. My bifacial system should hopefully be online in the next 60 days... so in about a year I can tell you how well it performs.

[RV10flyer]

I bought 20.6 kw of 430W QCells from Alt-E. I’ll let you know how they work in a couple of months.

[J.P.M.]

I bought 20.6 kw of 430W QCells from Alt-E. I’ll let you know how they work in a couple of months.

How do you intend to do that ?

Or, how do you intend to compare their performance to regular front faced only panels ?

[RV10flyer]

I looked at reviews, company size/history and the distributor alt-e. I knew I wanted new panels, not used. If I’m gonna spend two months labor installing my system, I’m not putting used equipment in. I could care less about bifacial or not. I wanted a distributor that would replace a broken panel in shipment. I wanted a distributor that would have more panels of the same model if I needed them a year later. I wanted a distributor that answers their telephone and posted how to videos online, because that shows me that they care about their customers not just profits.

As far as comparing bi-facial, I’m not trying to do that. I’m just recommending a distributor that I used and I’m very happy with and have bought many more items from them because of it.