How Efficient Are Bifacial Solar Panels?

[@FreedomInACan]

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[@joetripp123]

Those tilt mounts at 2:27 from Renogy say that only work on panels up to 28" wide but it doesn't look like you had any problems with the 220w cells at 30". I'm considering these as my first panels, these or the new 450w bifacials. I'm amazed at the flat results as well as the partial shading results. Both would play a role in my backyard ground mounted cells. A review of the 115w version shows up to 50% shading still produces good power - that's amazing and worth the higher cost per watt in many cases.. Thanks for the review.

[@FreedomInACan]

Yeah, I'm kind of surprised by that size limitation, because we had zero problems with the tilt mount. It was even the Renogy engineering team who loaned us the kit. I'd go for it. Also, your ground mount panel array sounds awesome, I think that might be the optimal setting for these bi-facial panels. Good luck! Be sure to use our affiliate link renogy.sjv.io/LPEyNY and promo code "CANLIFE" at checkout, to save 10%. Let us know how it goes, okay?

[@amz33894]

This was a great no bs review.

[@Crtulu]

Great review. Power facing the sun is one thing but facing away from sun and the partial shading test show off this panels technology. Thanks!

[@FreedomInACan]

Hey thanks for the comment, we are really excited about the versatility of these panels. Let's see where they can go!

[@stevertherver3887]

Looks like a great product. Thanks for the nice review! Safe travels!

[@FreedomInACan]

You're Welcome! Thanks for the comment!

[@driftingmelodies]

Isn't 86 watts from 100 wats one-sided panel much better than 186 watts from 220watts bifacial

[@FreedomInACan]

You have a point there. Here are some parameters that could explain the difference. 1. We tested the Bi-facial first, so slightly earlier in the day -- the sun was at a stronger angle when we tested the mono-sided panel. 2. We really didn't do enough tests in all light conditions, to gather enough data to confirm the overall better efficiency when compared with the mono-sided panel. 3. A better comparative panel would have been a 200W mono-sided rigid panel, but we only had our 100W Eclipse (which is more efficient than other 100W panels already). But the thing that we found in this short test isn't when the panels are set up in that "optimum angle configuration" but rather in a flat installation (which most RVer's are going to do on their roofs). Check out the video @4:25 where we have the chart. The Bi-facial is 80% of maximum watts, where the mono is 71%. Keep in mind the other features we discussed, low light angle, and even partial shading. Also the footprint comes into play as well, because this 220W bi-facial is smaller than regular 200W rigid panels -- so you might be able to fit more panels on the roof. These are all the real-world conditions under which in this test the bi-facial performed better. It all depends on how you're going to use your solar array, and under what conditions. Thanks for the question!

[@trainer4uu]

Great video! Thanks for sharing

[@MissionOffRoad]

Thanks for the video.

[@charlottekathrine1625]

Thanks for sharing, I am a little disappointed in the black vs white backdrop. Thought white would yield way more. So, again thanks for the education. Have you ever tested with a radiant foil?

[@FreedomInACan]

No we didn't test with that, would be curious. It is possible that a piece of coroplastic isn't as reflective as an RV roof. Hard to say... Thanks for the comment!

[@debidee5548]

The white paper backdrop was very thin a white tarp or white rocks or your white metal RV roof will reflect a lot more.

[@FreedomInACan]

@@debidee5548 Yeah, we thought that a white RV membrane could be the ticket.

[@QUADBOYification]

It would be interresting to know how much shading area has an output of 50%. I have my 4 bifacial 120 Watt panels mounted (4m x 0.8m) behind an apartment building balcony fence (Almost Stealthy) and it produces 200 Watt out of rated 4x120=480 Watts. Not bad if you consider these panels cost (& weigh) less than standard panels. My fence has 9 small fence beams a panel and due to the angle of the sun horizontally its shading increases. Ofcourse the shade is not completely dark but is more diffuse because of the surrounding daylight and the distance (1 cm) of the beams to the panels. The beams are white and my balcony area is mostly white also. I charge batteries. An MPPT system optimizes the output constantly. There is no other way to mount these panels.

[@muhammad484]

Great Job.

[@FloryJohann]

Bifacial panel co.panies claim to get power from the reflection of light. So why did you not face the power side of the panel to the sun and measure your power output and then cover the power side of the panel to see how much actual power that panel still receive without moving the panel. You did not even use the same kind of panel, your foldable panel will have less output since it got got more intetnal connections, so itbis not a compareable test.

[@FreedomInACan]

Thanks for the feedback. This was hardly a laboratory test, and we never intended it to be. We were merely trying to compare the percentage of the "real world" conditions vs. the rated watts of the two types of panels, 100W portable and 220W bi-facial. We're not comparing the two panels, rather under what conditions did one panel perform better with regards to the observed percentage of its rated wattage. And in terms of covering the front of the bi-facial, much of the power from the back comes from light passing through the panel itself -- it is clear glass, so we did not think that doing a test like you suggested would show much. Again, thanks for your insight.

[@mainemonty]

Nice commercial

[@FreedomInACan]

Thanks, hope it was helpful.

[@danielnicholls6868]

did you notice the reflection from the standard panels front surface onto the back of the bifacial. keep them a little more vertical and more off the ground to get more sun under front of bifacial👍👍

[@FreedomInACan]

Good advice! That precisely why I think these make excellent patio covers, or RV window awnings! Lots of great applications. Thanks for the comment!

[@handsomemehdi3445]

6:10 a good question. I have been wondering how the idea of making bifacial solar PV panels smart sounds. Is there very specific difference when compared to monofacial smart solar PV panels apart from your summary table at 4:24? Thanks for your response in advance. I must say your video was really enjoyable and interesting! Glad to watch!

[@FreedomInACan]

Thanks for the comment and questions. Since this is pretty new technology it's difficult to assess exactly where this will really shine in terms of efficiency. However, I think we've shown that in the variety of settings you'll experience as an RVer the bi-facial panels are more than likely worth the extra investment because of their versatility. As to your second question, we don't have any other specific differences - pretty much put everything we knew / had into the video. Thanks for your comment, really appreciate the feedback! Let us know if you have any additional questions.

[@WizzRacing]

I'm looking to get one of these just to charge a single 200ah battery...If I need to fast charge the batteries. I use the Renogy 2000 watt inverter\charger\transfer switch.. As I'm usually hooked up to shore power..Their DC-DC Controller gives me the alternator as 3rd option backup...

[@FreedomInACan]

Sounds like a good plan! Great to have 3 options to charge, and getting solar into the mix means that you really won't have to think about it much. Be sure to use our code and affiliate link to save some money on your purchase. renogy.sjv.io/rQQgvv promo code "Canlife" All the best, and let us know how it works for you!

[@WizzRacing]

@@FreedomInACan Well I pulled out the wallet and bought this thing during the sales this month. As they got more of these in stock today...This should give me 3 ways to charge battery bank...

[@FreedomInACan]

​@@WizzRacing Great, have fun with it! And good luck! Let us know if you have any questions.

[@WizzRacing]

Only question I had for them was the New Smart Shunt 300 0.. They mention it in a video. But does not show up on their website. As I got the One Core. And I think that is the shunt designed for the One Core..

[@FreedomInACan]

@@WizzRacing Good question, we haven't seen that either, we'll ask our contacts about it. We have the Core as well, haven't installed it yet - back logged on projects, but soon! We tested the Renogy 1 M1 last year in a video and also installed it on our friend's REGO system install - those are both videos on our channel. The only thing you definitely need to connect the Core is BT - 2 modules to your components, that way it can connect the data and display on the monitor unit. The REGO components all have built-in BT modules, but they are easy to plug in and connect to the wall, pretty inexpensive as well. There might also be a hard wiring option. Best of luck!

[@SuperMandme]

A mounting surface at least 3 feet is recommended from most sources for best bi-facial efficiency.

[@FreedomInACan]

Thanks for the advice! So, based upon this it might be best to install these as window awnings on the side of larger rigs. Not sure that 3 ft mounts on a roof would be as practical.

[@MrSmieglitz]

I have a comment on your test conditions having to do with the angles of incidence and reflectance you've neglected in your tests, especially when you turn the panels around. If you think about it, the panel surface is ideally set up perpendicular to the sun so direct solar is maximized. If the panel is off axis to that perpendicular path/axis of illumination, the efficiency drops. That should also be the case with reflected vs direct illumination. By turning the panels around, you've changed the conditions from illuminating the rear panels with a more direct illumination in terms of both incidence angle (a direct reflection from a surface illuminated by the sun) vs the original condition of a less intense reflection from skylight only (there can't be a direct reflection from the sun there since the rear of the panel situated in that orientation is in it's own cast shadow). Apples and oranges. Related to this, you might consider either elevating the panels and/or moving the reflecting surface further back from underneath the rear panel to maximize the less intense reflection from the skylight. You would also benefit from increasing the size of the reflector and maybe using some reflecting aluminized window shades in place of the white sheet you've employed.

[@FreedomInACan]

These are all great ideas and your insight is truly illuminating, thank you! 😁 In our video conditions we were trying to do the best we could with what we had at the time. A typical RV roof is unlikely to be optimized in terms of both angle and even reflectivity. But a more reflective roof, like the white membrane roofs that most modern RVs have, will certainly help. Our take away is that when not optimally angled the bi-facial seems to perform at a higher percentage. Yes, it's true that both panel efficiencies drop but the single sided dropped more. It will be interesting to see how people like these and the creative uses that arise. Thanks!