Best place to purchase Bifacial Solar Panels: projectswithdave.com/solar-panels/ California State Policy NEM 3.0 Information: NEM 3.0: what does it mean for you: t.sidekickopen60.com/s3t/c/5/f18dQhb0V1-gnj8dDTcYW39qybq2B9nMJN7t5XWPf2rmRN2zGJX-d0CtCW16gGF83Nsx19101?te=W3R5hFj4cm2zwW41RkQf1JylPtW49LlYL3zb1CvW3Fbt5S41RkwLW3_SP1B49M8XDW1G9VRH1Ld4CGW2fd0T14kCJp7F3H3c24PdkQ1&si=8000000022370865&pi=a1e716f6-023f-4c78-bd55-34cd5bc209a3
Dave, Another great video, but that is NOT a blizzard!! I have a 20kwp array of bifacial panels and I have 6 feet of snow below my ground mount array. If you are really in snow country you need a 45 degree pitch to slough off snow. The tiny loss of power in summer is insignificant compared to winter days when you need it (as you say)
Yes, I should have said it felt like a blizzard. The temperature was -40deg F with the wind chill. I grew up in Alaska, so I've seen my share of snow. And I agree, 45deg would be a better angle even for my location which doesn't see all that much snow. My winter production is my weak production time even without considering snow shedding.
I somehow missed this when it was published months ago, but here it is. I posted a remaining question about self clearing of snow on bifacial panels on steep winter angles below your bifacial video from July 2022 and just got my answer. Thank you so much for following through.
This is hugely helpful information Dave, and will definitely influence my choice of panel, it's location and how they are set up... Many of the comment are also helpful in this regard... I wouldn't have spaced my pannels for shedding, but this is obvious once pointed out... 👍
Thanks to your previous videos I purchased bi-facial panels for my ground mount and while I have not load tested I am confident it was the right choice so keep that info coming thanks.
I'm picturing SW and SE oriented sets of bifacial panels. The SW group can also get some morning sun on the back and the SE group getting evening sun on the back.
Nice, look forward to seeing the vertical analysis. This is a video I did on BiFacial solar fencing vertical .. th-cam.com/video/yDIUzC4xqFI/w-d-xo.html Bifacial Solar Fencing- Radical Transformation in Solar Energy Systems & Regenerative Agriculture
Adding reflective under the bifacials would be the first thing. Next, I would probably raise any fixed mount bifacial higher off the ground to allow more light in, especially from the front. Your test bifacials appear to be about 26" above the ground, it would be better if they started at a minimum of 42-48". You might consider mounting any future bifacials over a thin concrete slab and make sure you use white not gray Portland cement. Also, use a mounting system that doesn't have any supports directly under the panels rather using edge mounting between panels on the long side would be superior. Higher= more light & better cooling. It might be fun to test the bifacials in a vertical mount (like a fence) with the panel front facing east or west. Just decide whether you want the highest peak in morning or afternoon, either way no clipping! Expect amazing results with this one, especially in the snow. I am planning my new system and will be ordering 32ea. 400W bifacials in the next few days. It will be 2 arrays of 16 panels each with 1-axis auto-tracking and tool free tilt adjustment. Still undecided on inverter and tracking controls though. .
I would put in some heating rope on the back sides. The stuff we use to keep pipes from freezing. You wouldn't need much and the bifacial panels can run them bootstrapping the array. There are more efficient or lower power ways of warming the panels but all the same concept.
While rewatching this video I noticed at 3:28 (in winter snow) that the bifacial end of the array is shaded by those two trees. The low winter sun angle means you should top those trees 10-12' before next winter.
With bifacial panels and snow I have gotten better results at a steeper angle because they shed snow faster and the back side can get more light at a steeper angle.
One tip. It is better to shorten cables for energy efficiency than to roll them into a circle. The rolled up cable works like an inductor and hinders the transfer of AC power. It is also better just to make them go back and forth than in a circle if that is an option.
Hello from a 5% viewer. I live in south central Montana and this winter had a issue with my system going over voltage. I have 250w used panels and when the temps dropped into the double digit negatives my system shut down due to going 1 volt over the inverters max. Only had this when it was 0 or colder and clear skies. My fault, i didnt work our the math on the panels to include the change in voltage as temps dropped. Simple fix disconnect one panel from the string. I always enjoy your experiments and have learned a lot, and it has saved me time and money in the past so thank you for sharing your experiences with us.
Thanks for being one of the 5%! Thanks for your comment on temperature effects. Panels see their highest voltages in cold temperatures, and bifacial panels have an even greater delta in low temperatures.
Good video! I live in the Arizona desert and have a vertically mounted array pointed directly to the west. On overcast days, I get more productivity in the morning, due to diffusion of light in the clouds. So, I expected your results. Remember, a cloud layer will act as a light diffuser.
still think straight up [vertical] on there side and stagger back like a set of stairs. you should get a reflection from front of second or third row on to row in front of it. plus lets more light thru. yes on a shiny wall back 10 ft or more. plus space both sides of each row. less snow more reflection win win. bifacials at there best in cold snowy and cloudy days. keep up the good vids 👍👍 would still work good in late and early longer summer days with sun low NE and NW. shiny ground in front and under array to. and better wind flow around panels. maybe a vertical wall behind with regular panels
I think there are a lot of unique solutions that could be achieved with bifacial panels, but racking systems have not caught up with the technology yet.
I estimate the value of brushing off the snow in this video: th-cam.com/video/vY3PufzPUnI/w-d-xo.html Unless you live off grid and need the power, it's not worth the time. If you live where there is a lot of snow, you should have your panels at a much steeper angle so it sheds on its own.
Space out the bi facial panels. Like 1 foot all around to catch reflected sun from behind. Then test 2 foot or more. Single sided panels didn't need spacing that's why they are mounted really tight together.
What is the price difference between the normal panels and bifacial? You have established here that bifacial are better in some applications, but even a rough price comparison is needed. Great video as always, looking forward to the next one.
I got my bifacial panels for less than the cost of conventional panels through a clearance sale at SanTan solar. I have a few good sources with great pricing on my website under solar panels. Here's a link: projectswithdave.com/solar-panels/ You can can pay a slight premium and still come out ahead. I discuss the calculation in this video on bifacial panels: th-cam.com/video/1SXNjsSsmq0/w-d-xo.html
Love your content on solar man. I am planning out a solar install and am working on figuring out all the permitting and utilitiy contracting aspects of it at the moment. I am an electrical engineer so the system design part is easy but time consuming. You mentioning putting a pond behind the bi-directional panels gave me an idea of putting a small ground mount system by my koi pond. Thank you and keep up the great content.
I suspect, you will see some benefit from the reflection. I don't know how much exactly but I have talked to installers that will adjust estimated output when solar is installed near water do to an expected boost in production.
The cheapest way I could see to improve output at night would be to install lights at your panels that stay on through the overnight, especially with a good reflective underlayment. Solar powered lights that would be charged during the day would give back approximately 15% of the energy released and allow you to have lights on the panels for service during the night.
subscribed! I'm your freind from diysolarforum who was asking weird questions on FLA batteries. very soon I'll be upgrading to 550*2 bifacial solar panels, and based on my location I need to decide their height and inclination. 550w + 30% as the brand claims, they are also half cut. Brand claims them to be 22% effecient cells.
Nice! I've been thinking about replicating this somewhat using cheap used panels by putting panels on the north facing side of my roof.... On clear sunny days those panels won't see much benefit, but on cloudy days suddenly I would have double the panel area to soak up the diffuse light from the clouds. This would only be worthwhile if I get another very good deal on panels though. Last time I bought 110x 230W panels for $55 each. I would happily put the same panels on my north facing roofs if I got a similar deal.
Cheap panels give you lots of flexibility you didn't have in the past. If you are looking for more production in low light situations, and the only place you have to put them is on the north side, then this might be your only option. However, don't expect them to produce very much.
@@ProjectsWithDave for sure, I'm not expecting too much if I go that route, just some help with potential shortfalls on cloudy days. I have a small machine shop full of CNC machines so going solar will be my approach to getting 3 phase power, as that is not available locally. I bought 24kw of used panels to go on the south facing roofs, it will be interesting to see how it works out! I'll be using the grid as a 'charger' as well, but prioritizing solar input, and using both to keep approx 20kw/h of batteries topped up so they can be used in case of outages. We get lots of power flickers and outages here, which is not a good environment to be trying to run CNC machines! I'm looking forward to getting the system online.
I have vertical mounted 6x465w panels 2790w, dark clouds and rain 460w, overcast 780w, summer 1800w no white rock easy 30kw a day 3 arrays np, winter snow and sun 3414w and an undocumented sighting of 3700w. By sept I have 4 arrays, and this quoted array will be the weakest of 4. 2790/ 3255/ 3255/ 3630. I may have to shade the 3.6 slightly if it hits 4500w. Best part snow for 120 days and I never saw snow on any panels, it has been 10 months and now notice slight power loss due to dirt.
I too am Dave in Ohio. Really enjoy your measurement at real world useage. I have a small shed with solar, so I am new to the system but it always produces even with snow, but not enough to recharge the batteries. Use this system to recharge my ryobi 40 volt batteries and a golf cart that pulls 20 amps during charging.
So switch your panels from your shed to your ground array if they make no difference with the standerds being up there. Consider using a litle bit of energy from the bifacials to heat the standerds
My three arrays totaling 34kWp are at 45, 55 (facing SW after watching your prior video😊), 65 degrees. The two steepest are QC 475W G10’s. The steeper arrays shed snow quicker or at 66 don’t even collect it to begin with.
Bifacial Panels shine the cooler it is.. As they hate heat...I spray water on them in the Texas Summer time to cool them off. Then they put out more then the rated power using Renogy 220 watts. I have no idea how others perform...
Thanks! By the way, I'm not trying to "convert" anyone, just sharing what I learn as I go with my actual data. My goal is to give you data to process through the filter of your specific situation so you can make the best decision for you.
Have you tried installing the PV modules in a horizontal position? The diodes in the PV module will allow the production of energy even if the module is covered on the bottom side.
Dave: you should do a video on dump load energy storage. There are a few US companies distributing storage heaters (popular in Europe), but I think they have applicability in the US for solar dump load devices on those days when your batteries are full and the sun is shinning ..
Dave, you are doing some great work here. Very good data. I am working on compiling solar data as well. I have an Enphase system that I installed myself and I am looking at possibly building another array inground for testing all sorts of combos. Just curious about what state you are in? Ohio? Keep up the awesome work!
@@ProjectsWithDave I moved from Central Ohio to Central KY last year. What software are you using to gather per panel data? It looks similar to my Enlighten App used on my microinverters.
Thanks Dave. This is very helpful. I have bifacial panels in west Michigan and I have to say I'm disappointed that they don't do better on most cloudy days. I keep wondering if my design is not optimal. I still have more research to do. But it's good to know that your data says I made the right decision to go with bifacial panels.
Cloudy days just don't produce very much power. If you had conventional panels, you would be even more disappointed. You made the right choice in panels if it's a ground mount.
@@ProjectsWithDave Thanks Dave, I was trying to compare my solar output with yours as I wonder if I did something wrong with my set up. On my cloudy days I only get about 800w from my 9200w array which is a ground mount with all 460w Blue Sun bifacials. That is not even close to the 2000w the video shows that your array is producing in that snow storm. Could the difference in latitude make that much difference? Yes, there are cloudy days and there are CLOUDY days but I am judging based on what your snowy cold video shows. I also have to say that I'm not sure about my sunny day output where the most I have seen in 8000w with the panel angle set to perpendicular to the sun and that day was very cold. I have only been running since October. So I do wonder how they will do in the summer considering solar gain versus panel efficiency losses due to temperature. I am considering some kind of reflective surface behind the panels for next winter. Also, I put gaps between the panels in my array to increase the amount of light getting behind the panels.
Moment by moment production is not as reliable as long term data. Compare the output of your system over a a period of months against the predicted output by a calculator like PVWatts ( pvwatts.nrel.gov/ ). This will give you a better idea of how close you are to your systems true capability. Cloudy days can vary significantly in intensity. My cloudy day output can vary from 8kWh for the day to 23kWh. Density of the clouds makes a significant difference. Also keep in mind the online calculator is an average for a period of many years. My monthly output varies significantly from year to year as well. My lowest output for the month of January was 0.46Mwh and my best year for January was 0.819Mwh. It's very weather dependent.
I have Qcells bifacials just sitting on the ground in the snow waiting for spring to be mounted. They really do hate the snow and kick ass on sunny days with lots of reflected energy. I’m kicking myself that I didn’t buy more when I had the chance.
The snowy test didn't seem quite fair since it didn't look completely snow covered (100% albedo) and there was no snow under the lower row bifacial. Many areas would have the ground even under that lower area completely snow covered from blowing snow which would have helped the lower bifacial panel out. Would also help if you mentioned the angle the array is at and your latitude since that would also directly affect the output.
Unfortunately, we don't often have the combination of snow and sun where I live. So, I have to work with what I get. Hopefully, it is at least relevant data you can use to extrapolate to your situation. If I get a better snowfall next year, I can gather more data.
@@ProjectsWithDave Your results would be dramatically different. Deep snow with full sun is blinding. It didn't look bright at all in your clip. The sun was penetrating through the snow, plus all of the exposed grass (and obviously gravel).
What an AWESOME CHANNEL! Thank you Dave for doing this. I am looking to jump into solar at my property. Im rural like you. I want to do a 2 axis tracking system, do you have any input? Im in Wisconsin so this video was very helpful on Bifacial output and snow clearing value. Thank you
Thanks! My input at this time is that tracking systems are not likely to pay for themselves and I would only use one if I had limited space. If you want more power it would be cheaper to just add more panels.
Great review! I am no expert with bifacial panels, but I have seen some solar panel designs install the panels at a 90 (vertical) angle. This would minimize the shading of the snow by the panels and maximize the amount of sun to both sides of the bifacial panels. It would also allow the panels to shed snow more efficiently. To be clear, part of the reason for the vertical mounting was to allow easy access between the panels for agriculture farming. So the vertical mounting may not be the most efficient orientation for bifacial panels, but it would be very interesting to see if it produced more power in both summer and winter seasons. Just a thought.
At 49-degrees North Lat, my bifacials are angled 72(from horizontal) during Nov-Jan, then 60-degrees until end of April then 30-degrees unit end of October. This gives me the best total over the year, and yes during those summer months when the sun rises in the NE and sets in the NW there is a lot of collection from the back of the panels, similarly during winter months reflection off of white snow onto the back of panels is 10-15 % of the collected energy of those months.
@@r.b.l.5841 Interesting. You have done some serious homework. It is easy enough to figure out the best panel angle for single side solar panels, but bifacial panels appear to be a challenge. It appears that you made your rack assembly adjustable, so that you can change the panel angles for various seasons. That suggests you have a ground mounted system. Thanks for posting this information. I live in sunny AZ in the Phoenix metro area (in Peoria AZ) and I am going to install solar panels on my roof. I considered bifacial, but the added complexity of installing the panels at an angle on the roof is just not worth the trouble. This is especially true because newer panels have increased in to over 500 watts per panel. So I can install a 10 KW system with just 20 panels.. I think that using a Sol-Ark 15K hybrid inverter will allow me to capture most of the 10 KW output of the array and send it back to the grid, store it in a battery system and use it to power my house. Here in AZ, I would get enough power with a 10 KW array to power my house a week in just one day during the summer and still send power back to the grid. In the winter, it will still take approximately 1 - 1.25 days (theoretically) to generate enough power to power my house for a week. So essentially, I will not have an power bill at all. AZ pays approximately eighty percent back (of what I pay the utility company) in net metering, which is a pretty good deal. Your system sounds impressive. It would be interesting to see it.
@@franklong6269 I would not recommend bifacials for your set up, standard PV mounted parallel to your roof surface on fixed racking is much simpler to do, and if your roof slope is close to the same angle as your latitude north of the equator your golden. likely very little snow in Pheniox AZ too! (part of the reason my angle is steep is snow)
@@r.b.l.5841 Yes you are correct - 100%. You came to the same conclusion that I did. It just isn't worth the trouble to mess with bifacial panels in my situation. I would have problems permitting the rack bracing system if the panels were angled. And yes, here in the Phoenix metro area, it barely snows once every 30 years or so. So far this winter, the temperatures around my house have not reached freezing - though they have come close a couple of times. Thank you for sharing your hard-earned information.
As always, your videos are thoughtful, helpful and logical. I live in Northern Indiana, so I think many things apply also here. This is my year for investing into solar. BTW what is the angle of your ground array? Where there even steeper angles available in Ready Rack?
It's 30deg. That was the steepest angle they had when I installed it. I'm expanding my array right now and I found it's not hard to "cheat" it a few more degrees. Of course, that will affect the wind loading calculations slightly.
Thanks for the breakdown in real-world use. Ive seen a few builds where they use bifacials for carports and Pergolas. Any chance you will build one of those and show real tests for these use cases?
Thanks for the interesting video. I'm still experimenting with bifacial modules but I have two rows of modules so I'm wondering if I can tilt the back row to reflect light to the rear of the front row. I'll try it and see what happens!
Thanks this is very interesting but what nobody says is in a off grid setup when your battery is full it doesn’t matter what panels u have as you can’t use the power. Does it then pay to fit biracials? Here in S Africa there is about a 15% difference in price between mono and Bifacial panels.
The big advantage to bifacial panels it the increased performance in low light conditions when you need the boost. On cloudy and foggy days you will get significantly more production from bifacial panels.
How about a vertical mounted test with bi-facial panels. I would love to see the results as I have a possible application for this but I’m unsure if it is worth it.
What is the tilt angle of your solar array, Is it 35 or 40 or 45 degree? What do u think is the minimum tilt angle required to Not have snow stick to the panels, is 30 degree enough? I am thinking of building my solar array, Thanks! I think another thing you can do to maximize the bi-facial solar generation is to put like a 1 foot air gap between each solar panel column. So the sun light can go to the back side of panel easier. You seems to have unlimited space in your "backyard". So you can easily build another rack of array to have all the solar panel spaced out 1 foot.
My system is at 31 deg. If you can get your panels to 60 deg in the winter, you shouldn't have too much trouble with snow sticking. Make sure you have enough clearance under the panels to shed the snow.
The snow shedding is inaccurate if you look the other end shedded snow as well and there standard pannels I think it has to do with the fact that they are on the end and not cause there bifacials
Maybe you can't tell in the picture, but only the very top of the panels are clearing all the way across. The other end is not clear like the bifacial panels. There is a significant difference in snow clearing between the two styles of panels.
Love your videos. Where do u recommend getting ground mount racking system and I ve seen Santan site. But what do you suggest now 2024. For panels and where to get. I’m leaning toward biracial. Also I’m located in Southern Maine(Portland)
Thanks! Here are some good sources for bifacial panels: projectswithdave.com/solar-panels/ For residential home size arrays, there are two ground mount systems I recommend, you can find them at the bottom of my components page here: projectswithdave.com/components/
G'day Dave, does your 150% theoretical maximum fail to account for heating of the back of the panel? Maybe 100% + 50% doesn't equal 150% ? It must be really nice to have good sun on a cold day, Aussies don't get many of those!
I don't think so, the snow on my panels slide down the same way actually the ones I painted the back with a dark brown latex color the snow melts 200% better
Painting the back side would certainly help in the winter. However, in the summer it will also increase the temperature. That will significantly reduce their output.
I have two methods for gathering data. One is using individual optimizers on each panel with my Solar Edge system. The other is using dedicated oversized microinverters from NEP. I then record solar irradiance data independently with a Fluke solar irradiance meter.
I know you've heavily detailed your build process, but I guess I didn't realize how far your array was from civilization. Does one of your videos have details on distance and setup? I ask because the best options for arrays for me are fairly far from my house, and I have yet to research how such things would be wired up. It would be helpful to hear what you're doing.
Hi, I have a roof flat roof which is mainly oriented to the south-east. It is around 26m2 in dimension. I was thinking of installing some of the bifacial solar panels on it. But to mount it totally vertically like [ I I I I I ] with microinverters. What are your thoughts on that? Tnx!
I would not mount them vertical. It would be very hard to manage structurally. If the roof is white and you mount them at a steep angle with standard racking, you will save cost and probably get better performance.
Theoretically it would be the same. However, I've seen data to show some benefits from installing them vertical. I am working on a test setup that places them vertical. I'll post the results when I have actual data to present.
There have been a lot of requests for this and I have been thinking about how to mange the wind loading. I don't know of a racking system to accommodate it, so I would have to make something for the experiment. It would need significant bracing to be sure.
@@ProjectsWithDave I’m only asking to see if you tested any out and because you video on an extreme wind day and you had overcast weather and ice covered panels. I’m planning on a system that will be located on the Mesa and I hear it can get windy there and it is in snow country at 6944Ft elevation.
Ha, 😂 in Australia 🌏🦘 we get about 5-6 kW per day per kW. Much more that your system. My home is grid connected to export what I don't use. And just in case. Tesla batteries make a huge difference too. I am looking to upgrade to 20 kW of bifacial Trina S+ on my North facing roof. I have two different types now and want then all looking the same. 30 years will see me out i think. 😊😊😊
![[TH] 2024 PMSL SEA W2D1 | Fall | ต่อเนื่อง ในสัปดาห์สอง](http://i.ytimg.com/vi/ElcO9uC_Dbk/mqdefault.jpg)
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Best place to purchase Bifacial Solar Panels: projectswithdave.com/solar-panels/
California State Policy NEM 3.0 Information:
NEM 3.0: what does it mean for you: t.sidekickopen60.com/s3t/c/5/f18dQhb0V1-gnj8dDTcYW39qybq2B9nMJN7t5XWPf2rmRN2zGJX-d0CtCW16gGF83Nsx19101?te=W3R5hFj4cm2zwW41RkQf1JylPtW49LlYL3zb1CvW3Fbt5S41RkwLW3_SP1B49M8XDW1G9VRH1Ld4CGW2fd0T14kCJp7F3H3c24PdkQ1&si=8000000022370865&pi=a1e716f6-023f-4c78-bd55-34cd5bc209a3
I can see the white landscape rock being a good idea with a bifacial. Especially on cloudy days.
Dave, Another great video, but that is NOT a blizzard!! I have a 20kwp array of bifacial panels and I have 6 feet of snow below my ground mount array. If you are really in snow country you need a 45 degree pitch to slough off snow. The tiny loss of power in summer is insignificant compared to winter days when you need it (as you say)
Yes, I should have said it felt like a blizzard. The temperature was -40deg F with the wind chill. I grew up in Alaska, so I've seen my share of snow. And I agree, 45deg would be a better angle even for my location which doesn't see all that much snow. My winter production is my weak production time even without considering snow shedding.
@@ProjectsWithDave Wind chill doesn't count ;)
That's funny, that's what I always tell my wife! That's what they always report in the news in Ohio, makes it seem more exciting I guess.
@@ProjectsWithDave We married the same woman..
I somehow missed this when it was published months ago, but here it is. I posted a remaining question about self clearing of snow on bifacial panels on steep winter angles below your bifacial video from July 2022 and just got my answer. Thank you so much for following through.
This is hugely helpful information Dave, and will definitely influence my choice of panel, it's location and how they are set up...
Many of the comment are also helpful in this regard...
I wouldn't have spaced my pannels for shedding, but this is obvious once pointed out... 👍
Glad it was helpful!
Ive been on YT since the beginning and rarely subscribe to anything, but this content is gold:
I subscribed.
Thanks to your previous videos I purchased bi-facial panels for my ground mount and while I have not load tested I am confident it was the right choice so keep that info coming thanks.
Glad to help
DAVE, GREAT RESEARCH!
WE APPRECIATE YOUR SOLAR PROJECTS AND RESEARCH!
I'm picturing SW and SE oriented sets of bifacial panels. The SW group can also get some morning sun on the back and the SE group getting evening sun on the back.
Awesome analysis of BiFacial solar systems!
Thanks, I'm working on an analysis of vertically mounted bifacial panels now. It is going to be even more interesting.
Nice, look forward to seeing the vertical analysis. This is a video I did on BiFacial solar fencing vertical ..
th-cam.com/video/yDIUzC4xqFI/w-d-xo.html
Bifacial Solar Fencing- Radical Transformation in Solar Energy Systems & Regenerative Agriculture
Adding reflective under the bifacials would be the first thing. Next, I would probably raise any fixed mount bifacial higher off the ground to allow more light in, especially from the front. Your test bifacials appear to be about 26" above the ground, it would be better if they started at a minimum of 42-48". You might consider mounting any future bifacials over a thin concrete slab and make sure you use white not gray Portland cement. Also, use a mounting system that doesn't have any supports directly under the panels rather using edge mounting between panels on the long side would be superior. Higher= more light & better cooling.
It might be fun to test the bifacials in a vertical mount (like a fence) with the panel front facing east or west. Just decide whether you want the highest peak in morning or afternoon, either way no clipping! Expect amazing results with this one, especially in the snow.
I am planning my new system and will be ordering 32ea. 400W bifacials in the next few days. It will be 2 arrays of 16 panels each with 1-axis auto-tracking and tool free tilt adjustment. Still undecided on inverter and tracking controls though.
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thanks im definitely going to have to buy a pallet of bifacials when i do an array.
the natural snow melting effect is well needed here.
I would put in some heating rope on the back sides. The stuff we use to keep pipes from freezing. You wouldn't need much and the bifacial panels can run them bootstrapping the array.
There are more efficient or lower power ways of warming the panels but all the same concept.
While rewatching this video I noticed at 3:28 (in winter snow) that the bifacial end of the array is shaded by those two trees. The low winter sun angle means you should top those trees 10-12' before next winter.
With bifacial panels and snow I have gotten better results at a steeper angle because they shed snow faster and the back side can get more light at a steeper angle.
Yes, if you are in a climate with a lot of snow I would recommend an even steeper than mine, which is at 30deg.
One tip. It is better to shorten cables for energy efficiency than to roll them into a circle. The rolled up cable works like an inductor and hinders the transfer of AC power. It is also better just to make them go back and forth than in a circle if that is an option.
These cables are carrying DC power not AC. I did an analysis on the loops with my son, you can watch it here: th-cam.com/video/i7vHEHB3a-M/w-d-xo.html
Hello from a 5% viewer. I live in south central Montana and this winter had a issue with my system going over voltage. I have 250w used panels and when the temps dropped into the double digit negatives my system shut down due to going 1 volt over the inverters max. Only had this when it was 0 or colder and clear skies. My fault, i didnt work our the math on the panels to include the change in voltage as temps dropped. Simple fix disconnect one panel from the string. I always enjoy your experiments and have learned a lot, and it has saved me time and money in the past so thank you for sharing your experiences with us.
Thanks for being one of the 5%! Thanks for your comment on temperature effects. Panels see their highest voltages in cold temperatures, and bifacial panels have an even greater delta in low temperatures.
Good video! I live in the Arizona desert and have a vertically mounted array pointed directly to the west. On overcast days, I get more productivity in the morning, due to diffusion of light in the clouds. So, I expected your results. Remember, a cloud layer will act as a light diffuser.
Thumbs up 👍 interesting everyone is looking for plug and play. Very good project. Thanks 😊
still think straight up [vertical] on there side and stagger back like a set of stairs. you should get a reflection from front of second or third row on to row in front of it. plus lets more light thru. yes on a shiny wall back 10 ft or more. plus space both sides of each row. less snow more reflection win win. bifacials at there best in cold snowy and cloudy days. keep up the good vids 👍👍 would still work good in late and early longer summer days with sun low NE and NW. shiny ground in front and under array to. and better wind flow around panels. maybe a vertical wall behind with regular panels
I think there are a lot of unique solutions that could be achieved with bifacial panels, but racking systems have not caught up with the technology yet.
Suggestion: brush the snow off all the panels!
I estimate the value of brushing off the snow in this video: th-cam.com/video/vY3PufzPUnI/w-d-xo.html
Unless you live off grid and need the power, it's not worth the time. If you live where there is a lot of snow, you should have your panels at a much steeper angle so it sheds on its own.
Ok - you answer my question in another video - great info man.
Space out the bi facial panels. Like 1 foot all around to catch reflected sun from behind. Then test 2 foot or more. Single sided panels didn't need spacing that's why they are mounted really tight together.
What is the price difference between the normal panels and bifacial? You have established here that bifacial are better in some applications, but even a rough price comparison is needed. Great video as always, looking forward to the next one.
Totally depends on where you buy it from, brand, size, etc. I've seen certain bifacials a lot cheaper than mono facial panels.
I got my bifacial panels for less than the cost of conventional panels through a clearance sale at SanTan solar. I have a few good sources with great pricing on my website under solar panels. Here's a link: projectswithdave.com/solar-panels/
You can can pay a slight premium and still come out ahead. I discuss the calculation in this video on bifacial panels: th-cam.com/video/1SXNjsSsmq0/w-d-xo.html
Love your content on solar man. I am planning out a solar install and am working on figuring out all the permitting and utilitiy contracting aspects of it at the moment. I am an electrical engineer so the system design part is easy but time consuming. You mentioning putting a pond behind the bi-directional panels gave me an idea of putting a small ground mount system by my koi pond. Thank you and keep up the great content.
I suspect, you will see some benefit from the reflection. I don't know how much exactly but I have talked to installers that will adjust estimated output when solar is installed near water do to an expected boost in production.
You are doing VERY good work.
Thanks!
The cheapest way I could see to improve output at night would be to install lights at your panels that stay on through the overnight, especially with a good reflective underlayment.
Solar powered lights that would be charged during the day would give back approximately 15% of the energy released and allow you to have lights on the panels for service during the night.
subscribed!
I'm your freind from diysolarforum who was asking weird questions on FLA batteries.
very soon I'll be upgrading to 550*2 bifacial solar panels, and based on my location I need to decide their height and inclination. 550w + 30% as the brand claims, they are also half cut. Brand claims them to be 22% effecient cells.
Thanks!
Cloudy day performance is more important for off-grid systems that are drawing down batteries. Sunny days are more likely to top the batteries off.
Exactly!
Thermal panels should light up uv diodes that can feed the bifacial panels. INDOOR bifacial panels are in newsfeeds this week. We need videos on them.
Nice! I've been thinking about replicating this somewhat using cheap used panels by putting panels on the north facing side of my roof.... On clear sunny days those panels won't see much benefit, but on cloudy days suddenly I would have double the panel area to soak up the diffuse light from the clouds. This would only be worthwhile if I get another very good deal on panels though. Last time I bought 110x 230W panels for $55 each. I would happily put the same panels on my north facing roofs if I got a similar deal.
Cheap panels give you lots of flexibility you didn't have in the past. If you are looking for more production in low light situations, and the only place you have to put them is on the north side, then this might be your only option. However, don't expect them to produce very much.
@@ProjectsWithDave for sure, I'm not expecting too much if I go that route, just some help with potential shortfalls on cloudy days. I have a small machine shop full of CNC machines so going solar will be my approach to getting 3 phase power, as that is not available locally. I bought 24kw of used panels to go on the south facing roofs, it will be interesting to see how it works out! I'll be using the grid as a 'charger' as well, but prioritizing solar input, and using both to keep approx 20kw/h of batteries topped up so they can be used in case of outages.
We get lots of power flickers and outages here, which is not a good environment to be trying to run CNC machines! I'm looking forward to getting the system online.
I have vertical mounted 6x465w panels 2790w, dark clouds and rain 460w, overcast 780w, summer 1800w no white rock easy 30kw a day 3 arrays np, winter snow and sun 3414w and an undocumented sighting of 3700w. By sept I have 4 arrays, and this quoted array will be the weakest of 4. 2790/ 3255/ 3255/ 3630. I may have to shade the 3.6 slightly if it hits 4500w. Best part snow for 120 days and I never saw snow on any panels, it has been 10 months and now notice slight power loss due to dirt.
Excellent 👍
HOWdy P-W-E-D-D, ...
Thanks for the COMPARISON
COOP
the WiSeNhEiMeR from Richmond, INDIANA
...
So much wind. 😊 That is also energy...
Just more expensive to capture....
But if you have so much... its a waste if you have the space and velocity... still expensive is a deterrent. Thanks for the reply @@ProjectsWithDave
I too am Dave in Ohio. Really enjoy your measurement at real world useage. I have a small shed with solar, so I am new to the system but it always produces even with snow, but not enough to recharge the batteries. Use this system to recharge my ryobi 40 volt batteries and a golf cart that pulls 20 amps during charging.
Nice! Be careful, once you start producing your own power it gets addicting. 😀
So switch your panels from your shed to your ground array if they make no difference with the standerds being up there. Consider using a litle bit of energy from the bifacials to heat the standerds
Great video
Bifacials offer lots of options, vertical is one that we'll be trying.
I plan to do some testing on vertical solutions. Sounds promising.
Man that’s super fascinating. Thx for testing
Thanks for the hard data... Pretty much confirmed what I had assumed would happen! Especially the Bi-Facial Panels shedding the snow much faster!
My three arrays totaling 34kWp are at 45, 55 (facing SW after watching your prior video😊), 65 degrees. The two steepest are QC 475W G10’s. The steeper arrays shed snow quicker or at 66 don’t even collect it to begin with.
Great 👍
friend made little lake oround solar panels water helps reflect
Bifacial Panels shine the cooler it is.. As they hate heat...I spray water on them in the Texas Summer time to cool them off. Then they put out more then the rated power using Renogy 220 watts. I have no idea how others perform...
When the sun is actually behind the bifacial panels they really stand out compared to regular panels.
Yes, I think they actually look much better. In my case I see the back side of the array from my house, the bifacial panels are a much better look.
Great work, Dave. We're STILL planning our ground mount w/ batteries, but you may have converted me from the REC Pure Rs I had my eyes on.
Thanks!
Thanks! By the way, I'm not trying to "convert" anyone, just sharing what I learn as I go with my actual data. My goal is to give you data to process through the filter of your specific situation so you can make the best decision for you.
Great content, thanks for the work and inspiration to do it myself.
I might be late to the party but if you had a steeper winter angle you would have better results. Also less snow collecting or staying on the panels.
Yes, If I lived in an area with more snow I would use a much steeper angle.
Have you tried installing the PV modules in a horizontal position? The diodes in the PV module will allow the production of energy even if the module is covered on the bottom side.
The new bifacial panels are half cut giving the same effect, but that's a good idea for standard panels.
Dave: you should do a video on dump load energy storage. There are a few US companies distributing storage heaters (popular in Europe), but I think they have applicability in the US for solar dump load devices on those days when your batteries are full and the sun is shinning ..
That's a good idea, I'll keep it in mind. Thanks.
Dave, you are doing some great work here. Very good data. I am working on compiling solar data as well. I have an Enphase system that I installed myself and I am looking at possibly building another array inground for testing all sorts of combos. Just curious about what state you are in? Ohio? Keep up the awesome work!
Thanks! Yes, I’m in Ohio. Enphase is a nice product, but every time I look at it, I end up using something else because the cost is so high.
@@ProjectsWithDave I moved from Central Ohio to Central KY last year. What software are you using to gather per panel data? It looks similar to my Enlighten App used on my microinverters.
I use SolarEdge for my main array and NEP's system for the shed.
Thanks Dave. This is very helpful. I have bifacial panels in west Michigan and I have to say I'm disappointed that they don't do better on most cloudy days. I keep wondering if my design is not optimal. I still have more research to do. But it's good to know that your data says I made the right decision to go with bifacial panels.
Cloudy days just don't produce very much power. If you had conventional panels, you would be even more disappointed. You made the right choice in panels if it's a ground mount.
@@ProjectsWithDave Thanks Dave, I was trying to compare my solar output with yours as I wonder if I did something wrong with my set up. On my cloudy days I only get about 800w from my 9200w array which is a ground mount with all 460w Blue Sun bifacials. That is not even close to the 2000w the video shows that your array is producing in that snow storm. Could the difference in latitude make that much difference? Yes, there are cloudy days and there are CLOUDY days but I am judging based on what your snowy cold video shows. I also have to say that I'm not sure about my sunny day output where the most I have seen in 8000w with the panel angle set to perpendicular to the sun and that day was very cold. I have only been running since October. So I do wonder how they will do in the summer considering solar gain versus panel efficiency losses due to temperature. I am considering some kind of reflective surface behind the panels for next winter. Also, I put gaps between the panels in my array to increase the amount of light getting behind the panels.
Moment by moment production is not as reliable as long term data. Compare the output of your system over a a period of months against the predicted output by a calculator like PVWatts ( pvwatts.nrel.gov/ ). This will give you a better idea of how close you are to your systems true capability. Cloudy days can vary significantly in intensity. My cloudy day output can vary from 8kWh for the day to 23kWh. Density of the clouds makes a significant difference. Also keep in mind the online calculator is an average for a period of many years. My monthly output varies significantly from year to year as well. My lowest output for the month of January was 0.46Mwh and my best year for January was 0.819Mwh. It's very weather dependent.
@@jakejoeep23 Are you getting more than 9200W on a sunny day?
@@davidb.5544 Not so far. Just 8000w on the best totally sunny cold winter day.
Would be really interesting to see vertically mounted, east-west-facing bifacials. Snow shedding solved, and cheaper mounting hardware..
Where have you found cheap vertical mounting racks?
You should tack some house wrap behind the array to see if that helps. You have a black background, might affect?
I have Qcells bifacials just sitting on the ground in the snow waiting for spring to be mounted. They really do hate the snow and kick ass on sunny days with lots of reflected energy. I’m kicking myself that I didn’t buy more when I had the chance.
I wouldn't stress about it. I'm sure there will be opportunity for something new and exciting to expand with in the future.
That would be my summer angle. With my adjustable mount I'm almost vertical for winter solar collection.
Do you have bifacial panels? What latitude are you at? What winter angle gives you the best output? Thanks!
The snowy test didn't seem quite fair since it didn't look completely snow covered (100% albedo) and there was no snow under the lower row bifacial. Many areas would have the ground even under that lower area completely snow covered from blowing snow which would have helped the lower bifacial panel out. Would also help if you mentioned the angle the array is at and your latitude since that would also directly affect the output.
Unfortunately, we don't often have the combination of snow and sun where I live. So, I have to work with what I get. Hopefully, it is at least relevant data you can use to extrapolate to your situation. If I get a better snowfall next year, I can gather more data.
@@ProjectsWithDave Your results would be dramatically different. Deep snow with full sun is blinding. It didn't look bright at all in your clip. The sun was penetrating through the snow, plus all of the exposed grass (and obviously gravel).
Awesome reporting!!! They didn't have biface panels when I was buying solar.... I guess I just have to buy another array....
Sounds like enough justification to me! 😀
What an AWESOME CHANNEL! Thank you Dave for doing this. I am looking to jump into solar at my property. Im rural like you. I want to do a 2 axis tracking system, do you have any input? Im in Wisconsin so this video was very helpful on Bifacial output and snow clearing value. Thank you
Thanks! My input at this time is that tracking systems are not likely to pay for themselves and I would only use one if I had limited space. If you want more power it would be cheaper to just add more panels.
Thanks for the videos
Great review! I am no expert with bifacial panels, but I have seen some solar panel designs install the panels at a 90 (vertical) angle. This would minimize the shading of the snow by the panels and maximize the amount of sun to both sides of the bifacial panels. It would also allow the panels to shed snow more efficiently. To be clear, part of the reason for the vertical mounting was to allow easy access between the panels for agriculture farming. So the vertical mounting may not be the most efficient orientation for bifacial panels, but it would be very interesting to see if it produced more power in both summer and winter seasons. Just a thought.
At 49-degrees North Lat, my bifacials are angled 72(from horizontal) during Nov-Jan, then 60-degrees until end of April then 30-degrees unit end of October. This gives me the best total over the year, and yes during those summer months when the sun rises in the NE and sets in the NW there is a lot of collection from the back of the panels, similarly during winter months reflection off of white snow onto the back of panels is 10-15 % of the collected energy of those months.
@@r.b.l.5841 Interesting. You have done some serious homework. It is easy enough to figure out the best panel angle for single side solar panels, but bifacial panels appear to be a challenge. It appears that you made your rack assembly adjustable, so that you can change the panel angles for various seasons. That suggests you have a ground mounted system.
Thanks for posting this information. I live in sunny AZ in the Phoenix metro area (in Peoria AZ) and I am going to install solar panels on my roof. I considered bifacial, but the added complexity of installing the panels at an angle on the roof is just not worth the trouble. This is especially true because newer panels have increased in to over 500 watts per panel. So I can install a 10 KW system with just 20 panels..
I think that using a Sol-Ark 15K hybrid inverter will allow me to capture most of the 10 KW output of the array and send it back to the grid, store it in a battery system and use it to power my house. Here in AZ, I would get enough power with a 10 KW array to power my house a week in just one day during the summer and still send power back to the grid. In the winter, it will still take approximately 1 - 1.25 days (theoretically) to generate enough power to power my house for a week. So essentially, I will not have an power bill at all. AZ pays approximately eighty percent back (of what I pay the utility company) in net metering, which is a pretty good deal.
Your system sounds impressive. It would be interesting to see it.
@@franklong6269 I would not recommend bifacials for your set up, standard PV mounted parallel to your roof surface on fixed racking is much simpler to do, and if your roof slope is close to the same angle as your latitude north of the equator your golden. likely very little snow in Pheniox AZ too! (part of the reason my angle is steep is snow)
@@r.b.l.5841 Yes you are correct - 100%. You came to the same conclusion that I did. It just isn't worth the trouble to mess with bifacial panels in my situation. I would have problems permitting the rack bracing system if the panels were angled. And yes, here in the Phoenix metro area, it barely snows once every 30 years or so. So far this winter, the temperatures around my house have not reached freezing - though they have come close a couple of times.
Thank you for sharing your hard-earned information.
Good information when considering my next purchase.
Glad it was helpful!
put shiny aluminum sheets behind the panel to reflect the most light.
great information, thank you.
Glad it was helpful!
As always, your videos are thoughtful, helpful and logical. I live in Northern Indiana, so I think many things apply also here. This is my year for investing into solar. BTW what is the angle of your ground array? Where there even steeper angles available in Ready Rack?
It's 30deg. That was the steepest angle they had when I installed it. I'm expanding my array right now and I found it's not hard to "cheat" it a few more degrees. Of course, that will affect the wind loading calculations slightly.
Sinclair Designs ground mounts offer a seasonal adjust option you might want to check that out.
I'm familiar with that system, it's a good option. I link to it on my components page at the bottom: projectswithdave.com/components/
Thanks for the breakdown in real-world use. Ive seen a few builds where they use bifacials for carports and Pergolas. Any chance you will build one of those and show real tests for these use cases?
I've considered it... but, it will be a while before I get to a project like that.
Hello, friend! This is Phoenix from Amerisolar. Trusted Global Solar Module Manufacturer Seeks Cooperation
You can find my business contact information on the "About" page of my TH-cam channel.
Thanks for the interesting video. I'm still experimenting with bifacial modules but I have two rows of modules so I'm wondering if I can tilt the back row to reflect light to the rear of the front row. I'll try it and see what happens!
Let me know if you see any benefit from that.
Thanks this is very interesting but what nobody says is in a off grid setup when your battery is full it doesn’t matter what panels u have as you can’t use the power.
Does it then pay to fit biracials? Here in S Africa there is about a 15% difference in price between mono and Bifacial panels.
The big advantage to bifacial panels it the increased performance in low light conditions when you need the boost. On cloudy and foggy days you will get significantly more production from bifacial panels.
👍👍👍👍
The problem is that mirors should be 5 times bigger than bifacial panel!
How about a vertical mounted test with bi-facial panels. I would love to see the results as I have a possible application for this but I’m unsure if it is worth it.
I've had that request more than once. I'll have to investigate it when I have some time.
What is the tilt angle of your solar array, Is it 35 or 40 or 45 degree? What do u think is the minimum tilt angle required to Not have snow stick to the panels, is 30 degree enough? I am thinking of building my solar array, Thanks!
I think another thing you can do to maximize the bi-facial solar generation is to put like a 1 foot air gap between each solar panel column. So the sun light can go to the back side of panel easier. You seems to have unlimited space in your "backyard". So you can easily build another rack of array to have all the solar panel spaced out 1 foot.
My system is at 31 deg. If you can get your panels to 60 deg in the winter, you shouldn't have too much trouble with snow sticking. Make sure you have enough clearance under the panels to shed the snow.
@@ProjectsWithDaveoh, it is only 31 degree. I thought it is higher. Thanks for the info
Mica rock
The snow shedding is inaccurate if you look the other end shedded snow as well and there standard pannels I think it has to do with the fact that they are on the end and not cause there bifacials
Maybe you can't tell in the picture, but only the very top of the panels are clearing all the way across. The other end is not clear like the bifacial panels. There is a significant difference in snow clearing between the two styles of panels.
Love your videos. Where do u recommend getting ground mount racking system and I ve seen Santan site. But what do you suggest now 2024. For panels and where to get. I’m leaning toward biracial. Also I’m located in Southern Maine(Portland)
Thanks!
Here are some good sources for bifacial panels: projectswithdave.com/solar-panels/
For residential home size arrays, there are two ground mount systems I recommend, you can find them at the bottom of my components page here: projectswithdave.com/components/
Could you use a space blanket behind the bi-facial solar panels to reflect more light? Or aluminum foil?
Did you test a West oriented panel? Would get more light from the backside and produce from early morning, with a max in the afternoon.
I plan to do some further testing with bifacial panels in various orientations in the future.
G'day Dave, does your 150% theoretical maximum fail to account for heating of the back of the panel? Maybe 100% + 50% doesn't equal 150% ?
It must be really nice to have good sun on a cold day, Aussies don't get many of those!
You can see how I came up with those theoretical numbers in more detail in this video: th-cam.com/video/1SXNjsSsmq0/w-d-xo.html
What about mounting a mirror underneath the panels?
And how they perform in rainy cloudy winter?)
👏👏👏!
I don't think so, the snow on my panels slide down the same way actually the ones I painted the back with a dark brown latex color the snow melts 200% better
Painting the back side would certainly help in the winter. However, in the summer it will also increase the temperature. That will significantly reduce their output.
have you tried to put a reflective material under the solar panels like aluminum foil?
Not yet.
how would a 1 foot space between the panels affect performance, ie letting some light get through to the back of the panels.
It would improve performance, but it would complicate the racking.
How do you get info on each individual panel in your system? IE. watts, etc.
I have two methods for gathering data. One is using individual optimizers on each panel with my Solar Edge system. The other is using dedicated oversized microinverters from NEP. I then record solar irradiance data independently with a Fluke solar irradiance meter.
I know you've heavily detailed your build process, but I guess I didn't realize how far your array was from civilization. Does one of your videos have details on distance and setup? I ask because the best options for arrays for me are fairly far from my house, and I have yet to research how such things would be wired up. It would be helpful to hear what you're doing.
It all has to do with shading... You can get a computer program to analyze shades...winter house shade, and near by tree shade throughout the year...
Yes, this install video has most of the detail: th-cam.com/video/_xA6qOwnYbM/w-d-xo.html
Hi,
I have a roof flat roof which is mainly oriented to the south-east.
It is around 26m2 in dimension.
I was thinking of installing some of the bifacial solar panels on it. But to mount it totally vertically like [ I I I I I ] with microinverters.
What are your thoughts on that?
Tnx!
I would not mount them vertical. It would be very hard to manage structurally. If the roof is white and you mount them at a steep angle with standard racking, you will save cost and probably get better performance.
@@ProjectsWithDave thanks! 😊
has anyone sugested the obvious, mount the pannel vertically ?
Yes. I plan to test that once I get some time in my schedule.
Is the optimum angle for a bifacial the same as a conventional panel?
Theoretically it would be the same. However, I've seen data to show some benefits from installing them vertical. I am working on a test setup that places them vertical. I'll post the results when I have actual data to present.
Have you tried a biracial panel mounted vertically to collect both east and west light?
There would be extreme wind load on that configuration.
There have been a lot of requests for this and I have been thinking about how to mange the wind loading. I don't know of a racking system to accommodate it, so I would have to make something for the experiment. It would need significant bracing to be sure.
What will be the result if I install Bificial panels on L2 stand?
Ground arrays have the best performance for bifacial panels. From what I've seen, the higher they are off the ground, the better they perform.
Whats the result in hot summer day bifacial vs conventional
I plan to collect some of that data this summer.
Maybe time for a wind generator?
I haven't found one that makes sense to install. Feel free to make suggestions.
@@ProjectsWithDave I’m only asking to see if you tested any out and because you video on an extreme wind day and you had overcast weather and ice covered panels. I’m planning on a system that will be located on the Mesa and I hear it can get windy there and it is in snow country at 6944Ft elevation.
Why u put too far from home????? 😅😅😅😅😅
this video is like 1/2 commercials
Ha, 😂 in Australia 🌏🦘 we get about 5-6 kW per day per kW. Much more that your system. My home is grid connected to export what I don't use. And just in case. Tesla batteries make a huge difference too. I am looking to upgrade to 20 kW of bifacial Trina S+ on my North facing roof. I have two different types now and want then all looking the same. 30 years will see me out i think. 😊😊😊
Nice! It's much easier to justify solar in Australia.
Subscribed. Good video. Deliver or ill unsubscribe
Here is the bifacial roof result: th-cam.com/video/mzqjCsZKUYQ/w-d-xo.html
Dude, buy a coat.
Get some power optimizers