Some feedback on the experiment: You need to capture the power output not just the voltage. The latter is likely determined by the number of cells, but it does not guarantee you that the panels sustain a similarly high current. I would guess that the polycrystalline panel has a lower output current. Efficiency also considers power not voltage ratios. So your experiment on the "performance" is incomplete and therefore misleading. It would be nice to have the complete measures.
yes. and it is even more complicated then that. you can't just change your multimeter to current and measure short circuit current. you have to measure the current and voltage at its Maximum Power Point (MPP) in order to get the power output. That is what an MPPT solar controller is doing when it charges batteries or feeds back into the grid. Also the cells are wired in series not parallel. each cell generates ~0.5-0.6V. x 33-36 cells in series = 18-22V.
Polycrystaline panels have a higher voltage & monocrystalline have a higher current. There are more variations.. Cloudy days has light coming from multiple directions, which could aid poly While mono holds slightly higher efficiency in higher temperatures Poly's higher voltages can also mean inverters can work longer (they have a minimum voltage above which they operate It mostly boils down to, if you have enough space go to poly, if space is not a constraint poly
I’d like to suggest that you collaborate with someone with expertise in this field, like an EE, who can help you develop a more complete testing procedure. I think it would make a great final product and realize the potential of what you trying to accomplish with this video. As others have pointed out, the voltage readings you are taking are essentially meaningless without additional factors included. Additionally, as others have pointed out, the panels behavior will be dynamic and nonlinear, so there should be plenty of nuance you can explore in your tests, which would make the comparison even more worthwhile. I really enjoy your content and I want this to be an encouraging suggestion.
This panel can put out close to 100 watts ru-vid.comUgkxOqI2yqX0XVrhR2BMJciTWrHJpG8FhJyg when positioned in the appropriate southernly direction, tilted to the optimal angle for your latitude/date, and connected to a higher capacity device than a 500. The built in kickstand angle is a fixed at 50 degrees. Up to 20% more power can be output by selecting the actual date and latitude optimal angle.The 500 will only input 3.5A maximum at 18 volts for 63 watts. Some of the excess power from the panel can be fed into a USB battery bank, charged directly from the panel while also charging a 500. This will allow you to harvest as much as 63 + 15 = 78 watts.If this panel is used to charge a larger device, such as the power station, then its full output potential can be realized.
Just found your channel and love your style - so funny to hear your thoughtful and serious data based review suddenly interrupted by the Rock....refreshing and enjoyable YT channel - subbed!
Lady, you are good in dispensing information the right manner. I always enjoy listening to you, Thank you. I have hesitantly been considering installing solar power generation.
The most important thing is the wattage output under test and under load, you can have 2 panels with 20v under test but one could be 2.5amps and the other could be 2.2 amps, voltage × amps = watts. For example you can have a 2 car batteries that are both 12v but 1 could have double the Watt hour output or an 12v alternator that produces half the amps of the other. So voltage is only a small part of how to determine what panel is best, next time plug each panel to a charge controller and add the same load and you will be amazed with your results as voltage is determined by circuit load. Im a fully qualified electrician and have had solar panel installation training
Another great informative video. I hope you will continue to offer solar panel videos as the solar panel industry/ products continue to progress. Thanks again!
Monocrystalline solar panels have the highest efficiency rates, typically in the 15-20% range. This high efficiency rate means they produce more power per square foot, and are therefore very space-efficient. Monocrystalline solar cells are more efficient because they are cut from a single source of silicon. Polycrystalline solar cells are blended from multiple silicon sources and are slightly less efficient. Monocrystalline solar panels are the most efficient type of panel compared to polycrystalline and thin-film options. Typically installed for larger power systems in commercial and residential properties. 0:05 [Architectural Digest; Forbes; Geotherm Hvac com; Unbound Solar]
Down the rabbit hole of solar, baaaaaahh. Just when I thought my questions were answered apparently there are a lot more questions, lol. One question I would like to have answered is how to tell which ones are cheaply manufactured and who isn't? I suppose a second question is, how good are those flexible ones? A third question is can you have a mixed bag of types and does it degrade efficiency if you do? Ok, don't want to be greedy with my questions. Thank you Belinda and other responders. I am glad I found your channel.
I enjoy your presentations partially because you seem to present a considered and largely unbiased point of view with the information that you have on most subjects... the fact is that as humans we are all biased and discriminatory. It's hardwired into us as an integral part of our survival skillset and even if we are mindful of it and try to mitigate the effects on our choices it still has some influence on our perceptions, feelings, thoughts, actions etc. it's clear that you at least try and it is appreciated. I am of the belief that Experiments are rarely complete failures so long as something is learned from them. That which is learned may not always be what you set out to discover in the first place but thats the universe for you so we just have to deal with it. I make no claim to a scientific background 🤓but I can be awfully pedantic and certain things stick in my mind and one is that an ideal, sucessfullly thought out, planned and executed experiment should be repeatable and be consistant in it's structure subjects and conditions in every aspect especially when the exercise involves a direct comparison of two or more defined products, items, systems and the data that is expected to be collected is likely to be diverse and from that diverse data, expected to provide an actionable conclusion. If my understanding is correct, in this case you were exploring the various costs involved in production of those products, the installation of those products, not so much the care and maintenance of them but you did cover their performance overall. The defined periods of time and the conditions involved on those products however were not as well defined and to my world view which I am told can be overly simplistic, your experiment was more of a fact fishing expedition. It didnt quite cut the mustard where one or more of the aforementioned examination points were concerned. The conclusions left me uncertain. The presentation suceeded in that I'd want to research more on the subject to gain a workable understanding on the subject but I'd be hesitant to base a "to buy or not to buy" decision on those findings🧐... You still get a thumbs up and a smiley face 🤩because I'm a fan but...
One of my favorite topics! I somehow missed the other video, will watch it shortly. Love that you got working units to show, then I forgot whether mine are mono or poly, and want to go back to my carwash video to check, but I've gotta get to an appointment first.
I'd love it if you did a review on thermal solar energy collectors like an evaporative tube array!!! I do a lot of work with storing solar thermal energy for greenhouses and I love your reviews!!!!
One of the screens shown in that manufacturing video is fascinating. Due to the doping, the semiconductor junctions are not just light -> electricity. If you supply a forward voltage to the cell, it lights up. This is very dim, but can be seen in very low light with a long exposure camera. You can use this to see how well the soldering worked, check for cracked cells in a completed panel, etc. Great video as always!
With the voltage test you have mostly measured the number of series semiconductor junctions. There are definitely elements connected in series, or you would never get far beyond 0.7V, most likely around 0.6V, since every junction is also a silicon diode limiting its output voltage, but not limiting the harvestable current. Indeed for the mono-si panel with 33 series junctions, 0.6V*33 = 19.8V which tracks closely with your experiment. The poly-si panel with 36 series junctions should top out at about 21.6V by the same paper napkin math, which is by no means exact, but experiment is also within this bound. There also should be bypass diodes in the panel, external to the solar cells, to allow a partially shaded assembly to still produce some output. In order to account for this and several other factors, solar regulators use MPPT or "maximum power point tracking", applying the optimal load impedance to the panel or a homogeneous array depending on the output. Ultimately, unloaded test is of no meaning, you really can't determine their power without both a regulator and a battery or consumer that can take as much power as you're able to harvest.
You do need to measure both voltage and current to compare those panels, and preferrably use a MPPT solar charger as the panels might have different load curves.
Your channel is simply amazing, very informative and interesting as well. Love the hilarious clips, and your accent is very beautiful. Your video on shipping container scam drew me in, and was eye opening. Somehow your totally correct and logically sound arguments were hurting people's feelings over their hardset belief of saving the planet one shipping container at a time. LoL
To be clear, the power output is rated at 50W. This means that if one panel measured 14v and the other measured 20v, they would have a current output of 3.57A and 2.5A respectfully. The number of cells is irrelevant as it it more important as to whether they are connect in series or parallel. When the cells are in parallel, the voltage stays the same but the current increases for each cell added. When the cells are in series, the current stays the same but the voltage increases for each added cell. If you had 10 cells rated at 5v (volts) 1A (amps), you could connect them to get 5v at 10A or 50v at 1A. Ultimately, both systems would output a consistant 50 watts of power regardless of how you connected them, you won't get a penalty or benefit for either configuration, you just use which ever is most useful for your application. Neither cell configuration would be outputting more power than the other.
excellent video. maybe should have showed current while doing those voltage tests. the industry says mono is the way to go but when i saw many youtubers getting 105 watts out of poly thats where i put my money. i bought 4 rich solar 100 watt poly panels, wired them in series and rand that over 60 foot of 16 gauge wire and the max output was 398 watts. but my power production sucks bad in over cast days, so i bought 4 rich solar mono panels to test and use, but they haven't made it out to the yard yet.
Thank you for your efforts in presenting this information. Just to let you know, measuring only voltage does not give the power output of a panel. Just as measuring RPM only does not give the power output of an engine. A lawn mower engine at 2000 RPM, and a big truck engine at 2000 RPM do not both produce the same amount of power. With engines you also have to measure torque at load in order to calculate horsepower. With electrical generators including solar panels, you also have to measure the amperage at load in order to calculate Watts. I recommend people interested in solar to buy two panels, and four 6 volt golf cart batteries along with a 12 / 24 volt charge controller. With this equipment you can learn about series, parallel, and series parallel wiring by wiring it up as a 12-volt system, or a 24 volt system. Then you can take your bedroom Off the Grid! By the way, photovoltaic cells produce approximately one half of a volt each at load, a little higher unloaded. So each of those panels cells must have been wired in series.
I would be interested to know the comparison of how the output degrades over time (0y, 1y, 5y, etc). I also think you could spend more time on factors like: a. panel failure (availability of replacements, as an incentive to buy from an established “premium” brand) b. future increased efficiency as the technology improves (a deterrent against buying a very premium, top-performing model today) c. the efficiency of the two panel types at different angles (assuming most people have a static mount, is there an advantage to one type throughout the day/year? In other words, can you make up the cost difference of the mount is not optimal? d. does the pairing of micro inverters vs. a string inverter change the overall system comparing the two types of cells?
I like your videos. A couple of comments on this one though: Voltage is not output. The number of cells in series matters for voltage, but not for current, and power is the product of both. For a reasonable comparison, you are really looking to measure the maximum power point under operating conditions, including your partial shading. Just measuring voltage output does not tell you too much about the energy that they will produce. Just like measuring the pressure out of a water spigot does not tell you how much water you can get out of it in a given time. The power out is a function of the voltage and the current, so you need to monitor both simultaneously under loads to get an accurate picture of its power output. Some solar controllers, used mainly for battery charging drop the panels output voltage to just above the battery and the current at that voltage is what gets through to the battery. The panels you had there are basically configured for 12V battery charging applications in that the voltage will be high enough from the panel to push current into a 12V lead acid battery under most circumstances. Panels for such purposes generally have open circuit voltages under daytime solar insulation of between 17 and 22 V or so so that the voltage of the panel is high enough to push the current through to the battery. Other more sophisticated controllers monitor the voltage and current outputs of the panel or panels and calculate and hold the panel at the maximum power point, the voltage at which the panel generates the most power, and that power is converted to a voltage just high enough to push it into a battery, or an inverter to push back to the grid, depending upon the application. Solar panels designed for grid tie applications often have more cells in series and much higher output voltages, and are also often strung in series to voltages near 600V or even 1000V as at higher voltages you can move more power over a given size of wire with lower losses as the power lost is equal to the square of the current divided by the resistance of the conductor and the current is much lower with panels in series as compared to connecting them in parallel at lower voltage. The ability to use thinner conductors with lower loss makes solar installations cheaper.
When you blocked the sunlight from the panels with the paper and the towel, i wondered what wavelengths the panels absorb as the paper and towel may let some wavelengths (such as UV and IR) through.
Great video as always, except for the final statement about brand quality - lacking any evidence or quantitative data. Are lower prices a factor of volume or corner cutting? Are lifespans really reduced, because I don't see that (friends who install fields of solar see consistent failure rates pretty much irrespective of brand)... I would love it if you explored that more deeply.
Very good video, factual and interesting at the same time that is hard to pull off, so really well done. One thing which is also important is the average lifespan of these solar panels just as some added information, if their life span differs ofcourse. Love your videos, im here for more.
@@BelindaCarr Good information, but "useful life" is a fairly ambiguous term. What is the diminishing return in that 25 year "useful life"? That will affect the economics of a marginal, at best, investment. When the government subsidies are removed in the next few years it will be an even more marginal if not sketchy investment. To date, the group benefiting the most from the existing solar technology is the manufacturer. Payback, maintenance, diminishing performance all point the advantages of spending the money on a "super" insulated structure vs. alternate and inefficient energy products. Could you do, a study on the benefits of using efficient conventional systems, i.e. heat pump, mini-split systems, water heated via heat pump coupled with structure that incorporates R-50 plus walls and roof? An effective air seal plus a system using high R-factor and thermal mass combination will be a century long + investment rather than an expensive solar panel system and we haven't even gotten into the additional cost of the electrical wiring needed to make solar(or wind) practical.
More energy release is crucial so polycyrstalline is better especially when inclined. If it were like sunflower mode that is movement facing Sun will give more better output.
You could probably do a whole series on diodes and dump loads, the changing environment of feed-in tariffs, and the separate factors which govern the value of storage or production.
BC, The static voltage test is not measuring anything useful because there is ~zero current and therefore no power. Having them spin a fan or pump water and then measuring the power by simultaneously measuring voltage and amps would be more interesting. Timing the pumping a gallon of water alternating between the two panels would be an interesting test of Useful Power! ⚡ Hooking them up in opposition and seeing which one detonates first might be fun to watch! 💥 If you break one, Nuke a fragment in your ex's Microwave to see if you can create Plasma. 🔥
Open circuit voltage is what you measured and that is mostly proportional with the number of cells as all cells are connected in series and they are basically a diode and so have a voltage drop of 0.6 to 0.7V mostly dependent on cell temperature. The current is the one that is proportional with the amount of light. Unfortunately this smaller panels have fake ratings in most cases like the Renogy max power point voltage of 18.3V (just 33 cells) is not true an inflated to make the panel look better in terms of efficiency and rated power. The Rich Solar panel has more realistic spec so will likely be correctly rated at 50W. If you want to compare Mono with Poly crystalline panels the take large 60 cell panels from one of the top 5 or top 10 manufacturers as those panels will have correct specs as they are sold in huge volumes representing likely close to 80% of world production. Today there is no more than about 1% difference in efficiency between mono and poly and also almost no cost difference as the solar cells are a fairly small part of the total cost of the solar panels. Cost amortisation for solar panels is lower than $0.02/kWh making them the lowest cost energy source thus the reason I use solar PV to fully power my offgrid house including heating.
Great channel! I would be interested in a comparison at different times of day. I watched a comparison of 2 different kinds of solar panels on another channel a while back, i am assuming it was poly vs mono. He found that while 1 produced more energy at peak, the other produced more energy off peak. I believe his conclusion was that the 1 that produced more energy off peak(higher angle of incidence) produced the most total energy.
you shouldn't be measuring voltage but Watt's to test the capacity of the solar panels. Every solar panel will basically deliver its nominal voltage is 'some' light falls on it, even with indoor lights for example. However, it does not mean they will deliver the rated power in that situation
Your percentage of efficiency is off you need to check out the big companies that produce solar and look at their spec sheet it's a lot better than what you said in the video. Like for example check out Canadian Solar website, they just came out with I knew solar module in the earlier part of 2020 and their percentage is a lot better then what you are talking about. Actually there's a lot of things you got wrong but I'm just focussing on one.
You have to draw current from the panels to do any sort of useful test. Measuring voltage has no indication of power output. It's like comparing a D size NiCad battery compared to a AAA alkaline battery. The D size will have a lower voltage than the AAA size, but will be able to output much higher power.
I wonder why silicon ingots aren't cut longitudinally, for less wasted material and panel area. Obviously longitudinal wafers would vary in width, but all would be cut down to smaller standard cell widths anyhow.
Beyond the grain orientation of the crystals determining cut angles, longitudinal cuts never equal precision no matter what the material (wood, metal, plastic, silicon, etc.) Longitudinal cuts always incur greater thickness variations as materials flex under their own weight and precision is reduced the closer the cut is to the end since the material at this point is "floppy" as its only held on by a small sliver of material. This may not matter that much with wood or even some metal item that will be milled more precise, but silicon wafers depend on that precision.
@@bdwilcox Hmm, not clear why flexing would be an issue, with decent work-holding. But if length of cut is a problem, we can cut the ingot into shorter chunks before longitudinal slicing.
@@nelumbonucifera7537 Take a look at the "stack of pancakes" silicon deposition pattern in figure 13.10 here: link.springer.com/chapter/10.1007/978-3-319-48933-9_13. Now image cutting through that longitudinally with the resulting flex and vibration. It's like making an axe handle whose grain goes across the handle; any lateral force and it cracks.
i have both the poly runs cooler under the Texas sun during summer, thus sustaining a higher output longer. Mono runs noticeably hotter by 1pm output starts dropping.
The voltage output of an energy source does not determine its power value; the amount of current that the source produces is central to its value because it is the current that is actually being stored. The voltage is indicative of the resistance value being experience and this is inversely proportional.
Good video, however I would be interested in knowing output power vs angle to the sun. If poly is less angle dependent for stable output, then I would not need to have adjustable mounting angle for consistent power output in higher latitudes.
So is the 3 day cooling to minimize the amount of crystals in the panel? I know that that is what happens when you cool metals more slowly and wonder if that is what happens with these panels as well
Interesting video, thanks. If you do another panel video, you might mention that so-called 12V panels are really 18V. Go to Amazon and you'll see that the 12V and 18V panels for sale have similar specs - open circuit voltages of 20-24V and maximum power point voltages of 18V or so. The 12V mis-label possibly comes from the use of the panels to charge 12V batteries, but they really are 18V panels.
A better measurement would use 2 meters and a load. One meter for the current and the other for the voltage. Perform a power calculation. A load is very important or the measurements have no qualitative meaning. I did enjoy your video.
I don't think there's much of a difference anymore. They cost roughly the same per watt and are roughly the same size for the same rated output, so I don't know if mono panels are measurably more efficient anymore. In fact in comparison videos poly panels often outperform monos. If you correct for surface area, they perform basically the same. Mono panels may degrade a little slower. In this video only volts were measured, but if you measured total power my guess is they would be very similar.
These are the same result that I've seen on another channel. Unfortunately, I didn't see either video before I bought 1,600 watts of monocrystalline panels.
