Bifacial solar panels

[cotswoldstony]

Hi All, posting to find out how well bifacial panels stand up to the makers claims and if there is any member with them to comment.
Any help would be appreciated.

 

[nosys70]

well, solar panel should face sun to get the best yield.
so if you get another face, you can expect this face will get the worst yield.
unless you use mirrors or have a special requirement, i do not really see the purpose of bifacial.
and you can use regular panels mounted back to back, so this is not really a novelty, just a complicated way to mount solar panels.

 

[svetz]

The maufacturer's datasheets (for countries with consumer protections) are generally accurate; don't have them but believe you can trust the LG Neon2 Bifacial datasheets for example. Just keep in mind that like the panel's wattage is rated at STC, the bifacial power is rated on STC and albedo.

So, Bifacial panels are a real thing...but... there are some caveats with them such as they need to be elevated some minimum amount, extra separation, and you want a high albedo. SAM can model them. However, accounting for max power you might not see can increase installation costs.

 

[newbostonconst]

There are some cool installations where used for awnings....came very close to ordering some out of china but shipping was too much.

 

[Steve_S]

Bi-Facial panels can work very well in the right place and in the correct conditions can be quite productive. They are not designed for "roof mounting" as such, they are targetted to large solar farms where the background lands are "light" in the sense of deserts and such. Additionally, Bi-Facial Panels can be had that will generate more than 300W and if one looks at the latest in 350-500+W panels, these are mostly all Bi-Facial.

One supplier I work with a lot has been selling Bi-Facials for installation on roofs but these are not being installed on any old roof mind you. The roof is first redone with Pure White Galvalume and then the racking & panels mounted over that. Pure White reflects the full light spectrum back onto the backsides of the panels while providing a really good longterm roof as well. Any coloured roof will not reflect the full spectrum and obviously black will only absorb it.

When looking at Carports & Solar Pergola's or other structures "designed" for Bi-Facial panels, you will see that whatever background there is, even the light coloured concrete pad for the car is done so that light can reflect back onto the backside of the panels. It is essential to understand how & why these work and what it takes to get the most out of them for your investment.

What is Galvalume?
U. S. Steel GALVALUME® Steel Sheet is carbon steel sheet coated with aluminum-zinc alloy by a continuous hot-dip process. The nominal coating composition is 55% aluminum and 45% zinc. ... These attributes make GALVALUME® steel sheet the preferred material for roofing.

 

[ScoTTyBEEE]

On solar farms the light reflected off the panel is aimed at the back of the one in front. Outside of a snow covered solar farm their practical use is limited, even car ports are mostly useless since the solar panels will shade the area underneath and no light will reflect to the underside. Flat roofs are another good use when the panels are angled like a solar farm is.

 

[svetz]

I looked into them as my roof coating has a very high albedo; sadly with the hurricane force winds here there was no way I could elevate them as needed.

You don't really need snow or sand for high albedo. You could paint plywood sheets, use white gravel, or treat (paint) gravel.

 

[tictag]

I think these bi-facials are a fad. Eventually they'll be bringing out the multi-layered panels currently in the lab for the consumer market where all visible wavelengths and IR/UV light is absorbed - nothing gets through, nothing to be reflected onto the underside face. These bi-facials are too expensive, too much additional infrastructure required (reflective roof etc) and it's cheaper to buy another panel than eek out scraps.

 

[Liam M]

Reminds me of Solyndra.

 

[Will Prowse]

I am testing some right now and they are incredible. Still testing them against other panels and seeing how well they do in various environments. But so far, I love them. You have to find them at the right price though, some can be pricey. And they are heavy, about ten pounds more for a residential panel. But so far, 15-25% more output than my typical high quality brand new traditional mono panels.

 

[svetz]

... they are heavy, about ten pounds more for a residential panel. But so far, 15-25% more output than my typical high quality brand new traditional mono panels.

Very impressive output, can't wait to see what you did for that.

Don't have a reference, but saw an article once that they were sealed like "double-glass" panels, so should be very durable in harsh conditions (e.g., near saltwater) and might explain the weight.

 

[Forbisher]

I am personally using them at my home & the results are quite awesome. They perform well even in low light conditions like early morning or late evening. Here are a few things that you can do to increase the efficiency of

1. Make sure to clean them every week.

2. Paint the roof with white color so that more light gets reflected, increasing overall production or using a white roofing membrane.

You can consider the albedo values given in the above image. If you want to know anything else, feel free to reply to me!

Hey Harry
What's your relationship to the website you link to in both of the posts you made?
You are on topic but maybe you could have made 10 posts or 100 posts helping people before you tried to slip your google juice link in?
Your transaction posts make me doubt that you have panels and that you are just a paid SEO dude.

 

[kromc5]

I have 47 bifacial mounted and waiting on the last 3 that were damage and will have a total of 50. Hope to offer more information and how much they generate once completed.