Bifacial Solar Panels – The BEST Solar Panel Real World Results

Good morning, the sun is rising just over the horizon and starting to hit the backside of my array. It’s lighting up the backside of these bifacial solar panels. I’ve been studying, building and experimenting with residential solar systems for more than three years now. And I’m always looking for the technology and solutions that will deliver the best performance at the lowest cost. There’s a relatively new product on the market making big claims and that’s bifacial solar panels.

They have glass on both sides, exposing the solar cell to light from the front, and the back. Manufacturers are claiming to be able to produce up to 30% more power from the exposure on the backside of the panel. If that’s true, it’s a huge leap forward in technology. My goal was to answer the question, is this a revolution in technology or just a sales gimmick? I bought 24 new Canadian solar 390 Watt bifacial panels from Santana solar, a great source for discounted panels.

But things didn’t go as smoothly as I planned, the delivery truck accidentally dumped an entire pallet of panels upside down in the middle of the road. If it wasn’t for Santana’s great packing, I don’t think any of them would have survived. After recovering the situation, I went about testing them in real world conditions. I ran them through a gauntlet of scenarios to see what they can really do. I compared them back to back with regular panels on my 11 kilowatt array using my solar edge optimizer system and on my test rig using any P microinverters. I tried them with the backside blocked upside down full sun clouds to see if these panels really live up to the hype.

So let’s dig into the numbers and I’ll answer those questions for both of us. First, I put two panels on my test rig, which uses dedicated northern electric power micro inverters to prevent any clipping. One was a 390 watt Canadian solar bifacial and the other a 390 watt jinko mono crystalline, you can see the bifacial outperformed the standard panel all day long. But there’s a significant difference with and without the backside blocked, unblocked was about 14% more and blocked was still about 6%. More.

This was more significant than I expected since the test rig is very close to the ground. The improved frontside performance may be partially due to the improvements gained by the fact that it’s also a cut cell panel. Either way, the next step was to utilize my Fluker radiance meter to take measurements against its rated value. plotting out the PV output versus the solar irradiance gives a typical linear plot and allows me to compare the panel’s apples to apples on this plot.

You can see the unblocked bifacial is hitting its rated value at 1000 watts per meter squared, even on a hot summer day. If we extrapolate that out to 1200 watts per meter square, you can see on a perfect day, it’s possible to hit as high as 457 watts or maybe even more. When I put all three measurements at 1000 watts per meter squared. It’s easy to see how dramatic the bifacial performance increase is. The 390 watt jinko produces 87% of its rated value at 1000 watts per meter squared, which is a very typical result for a high quality panel, they usually get between 85 and 90% of the rated value. In the test that I’ve run on hot days using my inverters, you can see the bifacial with the back blocked reaches the high end of that typical performance and with the back unblocked, we hit 100% of its rated value. Even with high temperatures and inverter losses, I have never had a panel perform that well.

Now let’s look at a full sunny day comparison of the 390 Watt bifacial to a standard high quality 390 Watt monocrystalline panel back to back, my boys helped me replace two panels at the end of my cell facing array and axes by facials, I need to use these extension cords that I put together because the bifacial is come with very short leads. They’re intended for the most part to be just strung together in a string because I’m using these optimizers I need extension cables for that. So we’ll just go ahead and plug my extension cables into my optimizer.

And then what I’m going to do is run it on the edge of the panel with some zip ties keep it from blocking the light on the backside. I relocated the optimizers to behind my other panels so it wouldn’t block any of the light that could come from the backside. My goal was to minimize any shading for this test. This screengrab of the performance for the entire day is dark in the middle because I had to disconnect eight panels to prevent any clipping from interfering with my data collection. The two panels on the end are the bifacial panels. The gray line shows a whole day production in June for a standard jinko 390 watt panel.

And that day in June was very near the summer solstice. It reached a very respectable 2.82 kilowatt hours of output for that whole day. The blue and orange lines correspond to the upper and lower bifacial panels. You can see they produce significantly more power for the day. 13 to seven and 10% more power. And I didn’t even realize the top of the panel was covered with bird poop. So probably it would have been even better than that. Now let’s dig into how that was achieved a little bit because it’s really very interesting.

Since the sun rises and sets to the north, in the middle of the summer, I was hoping that the sun shining on the back of the panels in the morning and evening would make a significant difference in the bifacial panel performance. And if you look at the early morning and evening areas of the graph, I did see more than double the output. In fact, if you look at this chart that graphs the percent gain from bifacial over the standard panels from the axis on the right, you can see it reaches more than 150% of a regular panel. The problem is the sun just isn’t very strong that early and late in the day. So 100% of seven Watts is still only 14 watts.

This is the same reason why east and west facing panels really don’t perform that well. Either way, the total for the day is still a whopping 17% more power. But what about a cloudy day you ask? I’m glad you asked because I wanted to know as well. cloudy days tend to produce more general ambient light, which results in an even bigger Delta on a cloudy day, achieving close to 20% more power with that upper panel which is exposed to more of that ambient light. A snapshot throughout the day shows the bifacial panel producing as much as 100 Watts more power as a standard panel with the same rating. Now I know you’re dying to know how much these panels can produce under ideal conditions.

So I set up a test to prove exactly what the maximum would be. To prove this out, I installed two bifacial panels on my northern electric power microinverter test rig, one facing up and one facing down. I blocked the light from hitting the backside of the panels, so is only measuring the performance of the side facing the side. The result totally shocked me the performance was much more than the advertised 30% gain at 1000 watts per meter square, the backside of the panel was producing 66% of the power that the front side was producing. The backside facing panel gets a little bit of shade from the wires and the frame. But I’m sure the fact that it’s a cut cell helps manage that.

Let’s take a look at all this information together and draw some conclusions. A standard high quality monocrystal and plant panel usually produces 85 to 90% of its rated value at 1000 watts per meter squared. And ours was right there at 87% of its rated value. Our bifacial panel flipped upside down with the face block can produce an impressive 61% of its front side rated value. The front side of the bifacial panel with the back blocked produced a respectable 88% of its rated value. And with the back unblocked, it hit a record breaking 100% of its rated value. Now we did not achieve the max manufacturer advertised output of 130%, which this chart shows.

However, I didn’t do anything to try and take full advantage of the back with some type of reflecting surface or something like that. However, if we take the backside measured performance, and I combine that with the front side output, it looks like it would be possible to achieve almost 150% of the rated value. If you could somehow get full radiance on the front and the back at the same time, which would be pretty challenging. This is probably why they do so well in the winter with all the sunlight reflecting up off the snow plus the back can perform even when the front is covered with snow. I’m looking forward to getting some of those results in the winter.

And when I do I’ll bring them to you. If you have any ideas on how to maximize the sunlight on the back of the panels, put your ideas in the comments below. And maybe I’ll try out some of the great ideas that you drop down there. Now before you run out and buy these panels, there’s some physical differences between these panels and others that you should probably understand. So let’s take a look at those. Alright, let’s talk about some key physical characteristics of these Canadian solar bifacial panels. One they are much thinner than a typical panel. These panels are only an inch and eight thick. Your standard hardware that you’re typically using might not work with them.

The hardware I’m going to be using on my next install is k two systems and their mid mount self grounding clamps do work with this thickness. Their end clamp does not work as well. You need a slight shim to make it tighten up like it should, but they’re Yeti and clamp which slides underneath and has a nice hidden appearance does work perfectly fine bottom line, make sure that the mounting hardware you’re using will work with this thickness of panel. The second thing to consider is the MC for connection point. They’re very short, they come off from the middle of the panel. Now that works great and is very efficient. If you’re doing a string connection.

You can connect one panel directly to the next the wires won’t be in the way causing shadows and it works great but if you’re doing micro inverters optimisers or module level shutdown, you will need to mount those modules somewhere and these won’t reach them, they’re too short. In that case, you will need to have some extension cables, you can make them up like these ones that I made for the testing that I did, they’re really easy to make just get a spool of wire and MC four connectors, I’ll leave that information in the description. And then you can just connect them up. And now you have a longer cable, and you can use that to connect whatever module you need to connect to.

The other nice thing about that, you will be able to route your wires along the panel to make sure that you don’t have any shade shading on the panel. And while we’re talking about shading, that’s another important characteristic that you want to consider. We’ve already shown that these panels can produce a tremendous amount of power from the backside. But if you have a bunch of wires and optimizers and things, the structure of your mounting system shading the backside, you’re not going to be able to take full advantage of that.

So whenever you’re routing wires, or mounting modules, mount them as much as possible away from the backside of the panel along the edges so that they don’t cast shadows on the panel, you might be concerned that there are multiple connections to the back of the panel with the short MC for connections. But if you pop the cover off, you can see that the inside is completely filled. It’s totally sealed. And it has a very nice seal around each one of these modules.

So I think you can expect them to last for a very long time. Finally, an important thing to consider is how much they weigh, these panels weigh 62 pounds. And that’s because they have a glass back. Now there’s some really good advantages to having a glass back. One, it’s very well protected. You don’t have a vinyl back that can dry out and crack and fail on you. You have glass on both sides. But that comes with a lot of extra weight. So if you’re going to be putting these on a roof, you may want to consider Do you have the help that you need to get them up on the roof, or even on a regular mounting system, it’s hard to handle these big panels. Now I can carry him around. I’m not a very big guy, but it’s a lot of effort. So that’s something you definitely need to consider in your installation. Now let’s look at how to make sense of these panels from a cost perspective.

Unfortunately, both San Tan solar and signature solar are sold out of the 390 watt panels that I showed you today. They go really fast, but San Tan has a new one year warranty clearance 445 Watt Canadian solar panel at $230, which is the same price per watt as the one that I tested. And I expect will have very similar percentage increase in performance. And signature solar has a 460 watt blue Sun monocrystal in half sell for $271.40 Each, or $257.60. If you buy an entire pallet. I haven’t tested the blue Sun panels, but I assume they will have a similar performance to the Canadian panels. Maybe in the future, I’ll be able to bring some data on that. So this is how I would Crawshaw bifacial panels with other one sided panels.

For cost comparison, we’ll assume that the backside produces an additional 15%, which is pretty conservative for a ground array. Now one thing you want to consider if you’re putting these on the roof, you need a lot of space behind them, they’re going to perform the best with a white background or an open array. But from a cost standpoint, we just use a very simple formula, the cost divided by the wattage times 1.15% will give you the cost per watt. So let’s do a comparison of two 445 watt panels one’s bifacial, and one is a single face standard panel.

First, we’ll just take the $230 divided by 455 Watts and that will give us 52 cents per watt for the standard panel, then for the bifacial just take $230 and divide that by 445 times 1.15. That will give you the additional 15% Which would be $230 divided by $511.75. And that will give you 45 cents per watt. So from that analysis, you’ll be able to compare panels and understand how much more power you will get using these panels. So with a 15% boost, you’ll need fewer panels, which means less racking.

So overall, it’s going to be a benefit in a lot of different ways. But that’s a quick simple way to just look at the cost per watt as you’re searching for panels. Well, I can tell you if I were installing this ground mount solar array today, I would be using bifacial panels that have better performance on sunny days. But most importantly, they really shine on cloudy days in the snow in the morning in the evening. If you do end up purchasing solar products, please use the links in the description. It helps out the channel so I can bring you more useful content like today’s analysis. In future videos. I’ll be installing more of these panels and taking more data. So stick around for those results. If all of this seems like too much work, or you just don’t have time to do it, I have got a great free solution for you. And that’s enter GE power, they’re not beholden to any one supplier or any one manufacturer, they really are working just for you to help you find the best solution that’s going to work for your place. And they will help you understand if it even makes sense. So they aren’t going to try and sell you something that you don’t need. Not only that, if you use the link in the description below, and you end up installing a system through them, you get a $500 gift card. It’s really nice to have an advocate on your side, instead of trying to rely on whoever selling you a particular system that you may or may not need. One of the customers I talked to, said that one of the best things about having energy Powell on her side was if there was a delay, or she didn’t understand something, she could call energy Powell. They could talk to the supplier directly or help her solve the problem. And she wasn’t left trying to solve it on her own. So when you have to lose costs you nothing, you could get 500 bucks in the end, go ahead and check them out. Otherwise, stick around and you can learn how to not repeat all the mistakes I made on your system. So good luck on your install. I’ll see you next time.

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