West vs. South Solar Panel System Performance Winter Results - Actual Data

[@sciglassblower]

The most efficient design is to have some South-East, some South and some South-West. The panels will work at high efficiency at near 30 degrees so you don't have to point them East or West which will actually be less efficient because you will be loosing lots of production on these. I prefer to have more pointing South-West to collect energy late in the day especially on hot days because we have lots of mini splits running and one trailer air conditioner. The heat is worse late in the day and sticks around even after dark so late collection is crucial.

[@edwnorris]

Living in a more northerly climate, I've been wondering whether a ground mount at slightly more steep an angle than my latitude, with half the panels at about 30-40 degrees towards the East, and the other half 30-40 degrees towards the West. You'd lose production at noon in the summer, when it's hotter and more humid, and less productive anyway, and get more production in winter and closer to dawn and dusk, so a flatter, more even production curve across both the day and the year. More useful for heating with a heat pump, less wasted in the summer, and less clipping of the inverter, as well as a higher percentage of the inverter generally, so more efficient. Foolish? Or cost effective?

[@craigcarmichael5748]

@@edwnorris Some interesting compromises with different angles. First just the S. slope: I'm at 53.4 degrees N. and I put some panels on my S. slope roof at 18 degrees. The sun at noon on Summer solstice is still 30 degrees S so that's not optimum at any time of year. but COS 16 deg. is 96%. In winter however with the sun 76 deg. S. (14 deg. above the horizon at noon), COS 58 deg. is only 53%. And I probably lose considerably more to reflection at that steep angle. But there isn't much sun in the winter. If I want that bit of the 6-7 hours of low sun (when it isn't dark clouds anyway) I need to cut down the trees on my neighbor's acreage as well as my own. So I figure my optimum slope is around 45 deg. That's hardly any loss in the better 6 months, and still 86% capture in December. One other observation is that with the sun rising/setting so far north in summer, the sun is almost (if not actually) behind the panels at 45 deg. slope (still facing S.) in the earlier AM and later PM, while the flatter panels are getting more light. For orienting to more SE and SW, a steeper angle will catch more sun earlier/later in the day. At 60 deg. you'd still be getting 86% at sunrise/sundown, but they'd miss a good part of the day. At 45 deg. it would be 71% but you'd get a lot more later/earlier in the day. A still shallower angle will catch more of the day but less near sunrise/sunset. Sometimes I think of an arc of panels with (say) a 45 deg. sweep (more upright at lower latitudes), with the end ones facing heavily E/W and gradually more south at 45 deg. toward the center of the arc.

[@monkeysuncle2816]

OR 1: install a couple more inverters so there is NO clipping at noon, and be done with the whole shebang. 2: mount all the panels on a sun-chasing rotating mount.

[@crcurran]

I came here to say the same. Putting the three sets of panels in 90 degree increment is too extreme. It should be close to 25 - 45 degrees offset but taking into account ground based sun-blockage (buildings, tress, etc.)

[@christopherwilson5220]

Engineer 775 sets his up this way he referred to it as a flying v arrangement or somthing like that

[@sheriealfowler925]

Good information and well thought out. Maybe a southeast and a southwest side panels added to existing array might level out production without clipping but at an additional cost to system.

[@ProjectsWithDave]

Yes, I'm planning to set up a test rig to validate that hypothesis.

[@justinweatherford8129]

What about a southern facing half igloo shape?

[@Martinko_Pcik]

I would put west panels under bigger angle for winter because sun is lower plus the snow has harder time to collect on its surface. In my location, the optimal summernpanel angle is 30 degrees and in winter 60 degrees. There is also a lot of reflection from the snow on grounds so even vertically positioned panels work well

[@MattLesak]

Grew up in Ohio and this makes sense. Great explanation and it shows why doing your homework is worth it. I live in Florida now and getting solar on my home. Working with local company and they’ve shared great info that’s specific to our area. Biggest misconception about Florida is the amount of sun we get in the summer where I live. It clouds up and rains almost every day in the afternoon which impacts output. So adding more panels facing SE helps capture more power in morning when it’s clear.

[@ProjectsWithDave]

Good insight! There are tropical areas that cloud up and rain pretty much every afternoon. It pays to know the weather and sun patterns for your specific region and take it into consideration.

[@hcazonis]

This panel can put out close to 100 watts kzbin.infoUgkxOqI2yqX0XVrhR2BMJciTWrHJpG8FhJyg 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.

[@DansWay]

Awesome data-gathering and high production value Dave! Love your way of presenting the data. I know how much work it takes to put these videos together, both from the data gathering as well as the editing required. I have the exact same situation where I purposely clip in the winter. I even adjust my panels up in winter, and flat in summer, and I still get more power in January due to cold conditions vs. hot summer panels. I’m in So-Cal, so my angles are 32 in winter and 135 in summer so my elevation adjustments make a big difference. Thanks again for the data on the west facing panels as that is my next experiment as well. You might have already answered it for me with this video!

[@ProjectsWithDave]

Thanks, I appreciate the feedback! I'm glad the data was helpful for you. What method do you use to change your summer/winter tilt angle?

[@DansWay]

@@ProjectsWithDave I use IronRidge racking hardware which has adjustable leg segments as an option for tilted arrays on a flat roof. These aluminum tubes slide one inside the other to provide adjustability. For the summer I either slide them all the way down, or for some sections I remove them entirely to lay the panels even flatter. The problem with flat is they collect dust like crazy and the get really hot due to lack of airflow, so some angle is better than flat. I just released a 1.75 hour class for my company that talks about the fundamentals of solar and designing battery chargers. Don't know if you would be interested... mu.microchip.com in the Power Management section. You have to register, but it is free to do so.

[@monkeysuncle2816]

@@DansWay how can your angles be more than 90 deg off from each other? Are you burying the 135 in the ground? Or facing the 32 toward the ground? I'm new to solar, but shouldn't the range of angles be 0-90? "During the winter in the northern hemisphere, for example, the sun is low in relation to the horizon. In this case, for the solar panels to get their best performance, a steep angle of 60° is best. During the spring the best angle is 45°, and during the summer when the sun is high in the sky, it’s best to have a low tilt at 20°!"

[@DansWay]

I should clarify as we are talking about different angles. I should have said that the sun azimuth in the winter is 32 and 135 in the summer meaning that in the winter the sun comes up in the south-east at 32 (0 degrees is due south) and it rises in the north east at 135 degrees in the summer. I adjust my panels between about 5 degrees in summer and past 45 in the winter. The flat and hot panels in the summer only produce a little more sun than the angled and cold winter setup, even with a shorter day. If you really want to see how this all works, I have a class called Charging Batteries from Solar that I did for work. Check out mu.microchip.com and look in the power supply section for that class title. There is a chapter about MPPT Tacking that discusses this.

[@richardbrown6887]

@@DansWay Dan - Trying to be helpful, not harshly critical. In pretty much all the world, 0 degrees is North, not South. So your use of the opposite sense leads to much confusion about what you are really doing. Are you in the southern hemisphere, perhaps?

[@Thorsten_Wiegand]

Hi Dave. I have made a simmilar test with 2x 380WP Panels facing east and 2x identical 380Wp Panels facing south here in Germany. In the Summer the East panels really deliver full power in the early morning, as they already get full sun and the south panels produce around a quater of that, because they do inly partially get sun. In the winter the east panels perfrome really bad. In the morning they don´t performe much better than the south panels, because the sun doesn´t start east but south-east. Ad the rest of the day the east panels perform only 10% of the south panels. It gets better, if you change a angle of the east panels, leveling them up to almost a flat surface, allowing them to use the sun from all directing, even if they don´t get peak performance at a special time with that setting. I am using Hoymiles Microinverters (1x HM 700 und 1x HM600) for my panels. I have a monitoring device, that lets me monitor every single panel - similar to the solar edge system. You said, that with the microinverters, you would have to use 1 Phase, but that´s not true. You could use 3 Microinverter-Lines and connect each one to a different phase. For example, 10Panels with 5 Microinverters connected to Phase 1, the next 5 to Phase 2 and the rest to Phase 3. They have also inverters, where you can connect 4 Panels (but in this case 2 Panels share one MPPT).

[@ProjectsWithDave]

Thanks for the info. Sounds like you got similar results.

[@yankey4]

Grate video! Been working and living with solar for the past 20 years. Not seen someone show this so well. Will say on off-grid solar. It's nice to have that West power. In the mornings and late afternoon. This is when most peeps off-grid loads pick up. So having that power from the sun rather than pulling from the bank. Lets you have a smaller bank but still have the power when needed. Thanks for sharing. God Bless.

[@ProjectsWithDave]

Glad it was helpful!

[@Nifty-Stuff]

So glad Google finally showed me this video! I've been really curious about direction panels face. The calculations related to clipping are fantastic! It's all pretty complicated, and gets even more so when you factor in Time Of Use plans that (in some cases) may benefit from West-facing... but it would be great to layer that into your calculations!

[@ProjectsWithDave]

Glad it was helpful!

[@singlendhot8628]

Yet another extremely relevant and useful video. Well done!

[@arnecarlsson9740]

The microinverters are for grid tie instalations. They need to be connected to the grid at correct AC frequency to deliver power.

[@shrujanamsyama9940]

Even Dave is directly connected to the grid without batteries. So, in his case, it would have been advantageous to use microinverters. Even better would have been some Chinese inverter costing $1000 for 8kW as the panels don't face any shading and are continguous

[@sciglassblower]

We did stage our solar arrays from south to south west. Make use of the sun all day and especially late to reduce battery drain time.

[@simonclark8290]

I may have missed a comment to this effect but if you want more power in the winter and avoid clipping in the summer just angle the panels towards the lower sun so 30 degress from vertical for example. You may get even more output as panels are generally more efficient and colder temperatures and the steeper angle would discourage the snow to settle as much.

[@ProjectsWithDave]

Yes, a steeper angle does improve winter production, however, I thought I could improve it even more by adding panels East and West to take advantage of the "un-clipped" portion of the day.

[@simonclark8290]

@@ProjectsWithDave Yes. That's brilliant which is why I wanted to see what the outcome was. I've got some tree cover all around so it's always sub-optimal but I've got 22 on the roof and another 6 about to go up at 30 degrees off horizontal due south so it will be interesting. Your comments about East and West output on cloudy days were quite thought provoking as this is the weather condition I'd like most to improve the power over winter in the UK and it appears I can point them anywhere... maybe even North ;-)

[@awesomedee5421]

Great. I'm looking forward to the Summer data.

[@ProjectsWithDave]

Me too, I'm curious to see how different it is.

[@valeriooddone]

The panels should have an higher tilting angle for your case, in particular the ones facing east and west: - The sun is lower early and late in the day - you get more power in the winter and less in the summer - the panels remain slightly cooler in the summer, prolonging their life - The snow will not deposit on the panels, again improving the winter performance

[@ProjectsWithDave]

Yes, a steeper angle would probably also help in my case.

[@lotopy]

Thaks for sharing, in France the sun declination is also the same problem between summer and winter. I have installed 10 months ago 12x300W south, 6x400 west on the roof, and soon 6x400 east on the roof too.

[@ProjectsWithDave]

Nice!

[@shrujanamsyama9940]

Another excellent video with good analytics and calculations. I like this channel mainly because of the smart analytical and logical thinking with real world dataset instead of theoretical conjectures. Regarding clipping, the cheapest solution I see in your situation is to add 3 microinverters (3x$150) to the additional 6 panels while letting the 24 panels remain with the string inverter using an AC junction box ($150) to combine string inverter output and microinverter output. It should cost about $600. The only drawbacks to this is that it will need additional monitoring equipment at an additional cost to monitor microinverter output and also waste the money already spent on the 6 extra optimisers.

[@ProjectsWithDave]

Yes, I think the microinverter solution is a great way to expand at a low cost point. I'm going to do an installation with the micro inverters on my shed to try them out. I would not have done the west facing test array from a purely economical perspective, I did it to learn and share the results with the solar community.

[@diatonicdelirium1743]

@@ProjectsWithDave How would you hook-up the output of those panels? Plug them straight into the grid as a 'negative' load? I guess you might if their combined output is low enough. I did some small experiments the other way around to test my wiring, and found that a continued load of 2kW (@240v) put quite some heat into the wires.

[@gutsymovies]

SUPER interesting video! You built the wood supports for the west-facing panels at 30 degrees to the ground same as the south-facing panels. Could you get some improvement in the west panels by tipping them up to 40 degrees or 45 degrees? I would think the sun is lower on the horizon later in the day and you could capture more direct sunlight onto the west panels this way.

[@ProjectsWithDave]

That seems intuitive, however it is actually better to flatten them out because they catch the sun earlier in the day. When the sun is low on the horizon it is also low intensity.

[@cynthiaayers7696]

Using a carpenter speed square you'll keep it directly squared to the Sun for maximum power income, no matter the time of the day. Laying them flat, serves little good. Been-there-done-that. Age 65. PS. Make sure there is no Shadow around the speed square. Perfect alignment.

[@monkeysuncle2816]

@@cynthiaayers7696 I think he meant FLATTER, not flat. So a lowER angle, but not 180 deg flat on the ground.

[@USA-GreedyMenOfNoIntegrity]

Great job neighbor!! I’m in Kentucky 38 deg lat. My 20.6 kw array (presently constructing) is at 45 degrees and my original 1.6 kw array is at 53 degrees up from horizon, facing 187 degrees magnetic or true south. I have 4 high eff heat pumps totaling 6.25 ton, so I need lots of power in the winter.

[@ProjectsWithDave]

Nice work!

[@ssoffshore5111]

Geothermal sounds like a good fit for you!

[@kassandrakimbrell2504]

We did panels in thirds, one array southeast, one straight south, and one array southwest, and found the very best results that way. Im in Oregon, so I dont really know how that set up would work in other areas, fyi. Here, that is simply the best results know matter what we tried over the years.

[@ProjectsWithDave]

Thanks for sharing!

[@bradquinn4161]

You might want to talk to more off grid guys. They have been running SW facing arrays(partial) for decades in order to minimize battery draw for as many daylight hours as possible.

[@daviddarnell8898]

If your goal is to fill up under the clipping curve on winter afternoons. Then the West panels need to be placed where they never shade your South panels and directly face the sun at around 4:30ish on Thanksgiving. This probably means moving the array a little north angling them around 30 degrees South of true West and lean them forward to at least 45 degrees or perhaps even 60 degrees, i.e. much more vertical to maximize afternoon sun from late November through late January.

[@brucemurray2520]

Great info. I remember from years ago an article in Home Power Magazine. A business owner installed a split array behind his building. He had half pointing lets say at 150 degrees and the other half at 210 degrees. This flattened the top off of the normal bell curve. In his case he needed the power mostly during business hours. He ended up with a lower but much broader peak output. Bet bifacial panels would provide really good performance in such a layout.

[@ProjectsWithDave]

Yes, I think bifacial panels bring a new strategy to the whole activity.

[@campbellsoup4910]

Dave Dave Dave! We need you running the country's solar department 🤔 really appreciate the information, great work 👍🏼

[@ProjectsWithDave]

Ha ha, thanks, I appreciate the encouragement. : )

[@shawnd567]

I have a western array on my roof in the upper Midwest. Snow is a big problem but it performs great in the summer with evening cooking and AC. A tracking system will always be the best way to go. 2nd best is south. 3rd is one array facing east and one west. 4th is facing west and last place is facing east. Most power is used in the evening.

[@ProjectsWithDave]

Thanks for sharing!

[@jessstuart7495]

I also have a Solar-Edge DC optimized system but with a 6.4kW inverter. My home in the suburbs is not aligned with the cardinal directions, and I don't have a really good south facing roof to mount panels. I have 12 panels pointed in a WSW direction, and 8 panels in a SSE direction. One thing I wish I had considered when deciding where to mount the panels was the daily weather. Where I'm located, we often get afternoon clouds, even on sunny days. Having some of my panels point in a westward direction, these afternoon clouds hurt my afternoon power production. Mornings are usually very sunny. You might want to look at some weather data on cloud cover and see if there is a significant difference between cloud cover at different times for your location.

[@franklong6269]

I give you credit for learning about micro inverters - it shows that you are intelligent and you are evolving. This is a very well-done video! As you note, had you used micro inverters that were properly sized for your panels, it would have cost you more but it would have solved most of your clipping problems. It would have saved you considerable time trying to fix your current setup. Also, micro inverters have verifiable longer service life and are more reliable. They generally have twice the service life of a string inverter, depending on which brand of micro inverter you are using. Further, if one micro inverter does go down, it only disables the panel that it is connected to. Some new micro inverters can be connected to two panels and a few can be connected to four panels, but it is economically reasonable to use one panel per panel when you consider that you can size the micro inverter to eliminate clipping in the panels. For example, with your system, your central 7.6 KW inverter cannot handle the peak sun hours from your 11.4 KW solar panels. Your 7.6 KW inverter costs in the $4500.00 with the optimizers. New micro inverters can handle up to 500 watt panels. They also tend to be more efficient than string inverters. So you would eliminate all clipping issues and the inverter costs would be approximately equal. Also, many micro inverters manufacturers provide software that allows you to track the actual power generation of each individual panel, as well as checking on the "health" of the panel. Your information in bi-facial panels is very useful. Thanks. This is an exceptional video - great job!

[@ProjectsWithDave]

Thanks! I did install a micro inverter system to start testing that solution. You can see the install here: kzbin.info/www/bejne/j2myeKuaf56Wi5o

[@bloodynorahvan2203]

Hi from the UK 🇬🇧 I learned loads from this video - thanks for putting it together!

[@ProjectsWithDave]

Glad it was helpful!

[@philippserrin8268]

Given that solar panels are now so cheap, the best “solution” may be to have half of the panels pointed approximately SE and half of them pointed approximately SW. The difference in the direction the two sets faced should be calculated so that the sum of the power generated by the SE panels plus the power generated by the SW panels adds up to the desired level of slightly above the inverter capacity. This angle would vary depending on the season, but depending on one’s seasonal needs, an optimum set of angles can be determined.

[@Controlly1]

I like this solution and it would help the self consumption which is a big thing here in Europe since we're getting peanuts for the power we put on the grid. Having a wider production window would be really beneficial!

[@deerswatter9561]

SE/SW would also help melt the snow.

[@randymch]

I really enjoyed the first ten minutes of this video and then I enjoyed the best nap of my life.

[@ProjectsWithDave]

Glad I could provide such a high value nap for you... : )

[@jacksonwhite23]

Looking forward to seeing the SW facing video!

[@ProjectsWithDave]

Great! Me too : )

[@chrisb9319]

This really comes down to whether your setup is grid-bound or an island and how much you get paid for kWhs put into the grid or how much you can practically use yourself. Here in Germany you currently pay a minimum of 30 cents per kWh and only get 7 cents per kWh you put into the grid (for new installations connected in 2022). So our main concern is to use as many kWhs ourselves and pushing peak production from noon to the morning and the afternoon has a much greater effect than simply producing as much energy as possible since we're not able to use all of it.

[@ProjectsWithDave]

Yes, understanding your own unique set of circumstances is very important to developing the right system for you.

[@fredpinczuk7352]

If you are all ready clipping power in January, can't imagine the out come in June-July-August without the micro-inverters.

[@CyberlightFG]

If you use 2 inverters with 2 mppt trackers, clipping could be reduced by connecting 1 string from the east array and one array from the west to the same inverter. They can both work at full power. Or just use one big inverter with 2 mppt

[@diyrenewableenergyelectron4996]

I like the winter solstice breakdown in this video. I was thinking about this and realized that most days are cloudy anyway, so the gain from facing south is minimized over east or west. I’m looking to mount panels on my East/West facing roof and was concerned about winter production but I think weather and clouds will impact output far more than the direction the panels are facing.

[@magyardeutschusa]

Nice. My roof is 15 degrees east of south. On a sunny day, a west less15 degrees south facing panel produces as much as a panel facing south plus 15 degrees east. In summer, this is especially beneficial at countering the afternoon air conditioning load. At 15 degrees, solar kicks in a little earlier, but extends later in the day during peak power consumption (especially summer).

[@mentality-monster]

Great video, thanks. Love that you're called "Every Dave" and you're using polynomial equations in excel!

[@ProjectsWithDave]

Thanks : )

[@MarkRose1337]

That's the first time I've seen data for south vs west/east solar collection. It was interesting to me that the extension of power into later hours was so short. That tells me in more northern latitudes, say 50 to 60 degrees, where the sun cross a smaller arc of the sky, entirely south facing panels will be even more optimal for winter. This was useful. Thank you.

[@ProjectsWithDave]

Thanks!

[@NorthMatt92]

Thnkyou for the information, by far the best breakdown of this I have seen. And thankyou for including the data/math. Definitely going to help with my array.

[@ProjectsWithDave]

Glad it was helpful!

[@meganwinters5163]

I have to agree with the bi facial array statement; More light being absorbing from sub optimal angled sun light, equates to a overall broader "non-clipped" power curve. This is why I love my bi facial array ❣️ also the fact that I can still garden underneath them is a huge plus in my opinion. Subscribed & awaiting more experiments! Thanks again 🙏 I appreciate all your hard work!

[@ProjectsWithDave]

Nice! I like the idea of bifacial panels with a garden underneath. I'm sure that helps a lot with mitigating the intensity of the sun during the heat of the day.

[@meganwinters5163]

@@ProjectsWithDave it really does! Agrovoltaics is such a great symbiotic relationship. Albeit "lower light plants are grown" (you'd be surprised if the vast varieties) they respirate water from too much sun light, cooling the underside of the panel. Panels help with moisture retention in the soil which leads to less overall water usage in the garden. Ultimately, I get better power creation and food to eat 🌄🥗😊🙏. I'm a Happy camper!

[@SpeedyC3]

best video i have ever seen i freaked out every move that was awesome!!!

[@rayopeongo]

How about the tilt of the panels? The sun is higher in the summer and lower in the winter. If you tilt the panels more steeply, I see a few benefits. One, they will maximize production in the winter from your fewer hours of sunlight, when you presumably don't usually get as much power as you need. Two, they will shed snow more easily. Three, because the panels are not optimally tilted for the summer sun, there might be less clipping in the summer. I also assume that you generate more power than you need in the summer because of the longer hours.

[@ProjectsWithDave]

Using the PVWatts calculator ( pvwatts.nrel.gov/ ), it appears west facing arrays perform better at my latitude with a shallow angle. It captures more of the light earlier in the day when the sun has a higher irradiance.

[@kennethhansen9860]

Dave, Have you considered the angle of the panels with respect to the ground? In the winter, the sun is lower on the horizon, and therefore at a decreased angle to your panels. Maybe having them set at 45 degrees might give you greater output. Then go with 10 se, 10 south and 10 to the west. Just a thought.

[@ProjectsWithDave]

A little steeper angle would probably meet my needs better, but it would be difficult for me to make that change now.

[@mikebroom1866]

I have a LOT of E/W facing roof and not much south over here in indiana. Optimistic goal is to utilize both, but cost is very high, especially with used decent panels in short supply right now. Definitely looking forward to more data.

[@ProjectsWithDave]

If you want help, I'm sure EnergyPal can help you determine if solar makes sense for you. You can connect with them here: energypal.com/everyday-dave

[@DaveM-mp6yu]

You might also try tilting the east west panels closer to vertical to pick up sunlight at close to 90 degrees in the winter. Good info thanks.

[@jhfl1881]

I think your SW idea is a smart one. SE might not pay as well, as mornings are colder and it may take much of the morning to burn frost or fresh snow off the panels before the system is up to speed. Splitting the system I would hope might limit summer clipping too. We will stay tune to this cliff hanger!

[@DavidCheok]

When you are on the equator, the sun rises and sets NE/SE or NW/SW depending on the time of year. Its a whole different ball game.

[@raullasvegas]

I was wondering this same thing. The issue is to maximize collection on bad days. If I have sun in the morning, or evening, would the angled panels work better. Can you get more consistant collection with the angled panels. The 90 degree east/west wouldn't be something I would do but 45 sounds like a better number. You also put your west panels to the west of your array. Put it on the east of your array. Have the east facing panels on the west of the array. I feel if you did the U that way, snow wouldn't be as much of an issue, and if you had bifacials, they would work better.

[@UBAYBE]

What about a 45 degree SouthWest facing? What if you had "Mirrors or light dircors" to move light towards the panels in the am and pm, and not during the noon clipping time? What if your panels are all on rotating trackers?

[@chrisspy1226]

awesome and thanks! I don't understand why you don't clean snow, especially from West array

[@ProjectsWithDave]

You can see why in this video: kzbin.info/www/bejne/rIqWgaicr7WIpKs

[@Zorlig]

Glad you are discussing doing the V shape array towards the end, I think that ends up being best and hopefully you'll be able to show that later with data! If you are just doing grid tie.. go with a larger inverter and everything south facing if you really want to not clip. Panels are so cheap, might as well clip. From what I can see.. having panels facing directly to the sun where it comes up/sets apply more to off grid systems where you want to limit the chance of having batteries run empty. It seems like the degree of a V maximizes that, which is what I plan to do. Like you say, plenty of power in the summer, so optomize for the winter!

[@jeffsteinmetz7188]

Good data! Question: If your objective is to catch later afternoon sun why not have a steeper angle on the west facing panels?

[@ProjectsWithDave]

It's counter intuitive, but steeper angles on west facing arrays tend to reduce the output at my latitude. When the sun is low on the horizon it also has lower intensity.

[@danielnicholls6868]

would 4 bifacial panels two facing east two facing west but straight up and down should work even better. worth a try

[@ProjectsWithDave]

I think the bifacial solution brings a whole new element to the equation. I would like to get some and see the impact.

[@TheyCalledMeT]

i wold not have chosen 90°, that was definitively too much, i would pick something like 45° +- a little and do the same with south eastern facing panels but you put out an interesting observation pointing to a problem most people won't be aware of untill it hits them and offer a very pragmatic solution for it EDIT: ahaha .. you came up with the same solution at the end of the video :) edit2: i would steepen up the the SE and SW facing panels a little since they will face the sun while rising/settling not being on it's peak

[@Jamesvandaele]

What I want to see is a vertical setup utilizing the snow reflection with a few with standard angles.

[@isettech]

Highly recommend making the panel connection changes after dark to have the panel voltages off while making changes.

[@ProjectsWithDave]

Yes, I'm sure that is a safer approach. Thanks

[@danielnicholls6868]

sun is lower in east and west plus snow reflection will add more power.plus less snow on them.

[@litnoregrets7551]

I love this video. So technical and so interesting. Thank you for making this.

[@mdonau81]

please watch out for "voltage blocking" MC Electrical has a good video on the Problem, with only 3 optimizers it will be hard to get the necessary voltage for the inverter. the +-45° (SE/SW) setup is imho the best compromise and can run a cheap string inverter with 2 MPPT

[@ProjectsWithDave]

The three panels is only for testing purposes, I'm watching the voltage to make sure I'm not clipping the West array. It hasn't been a problem so far. As you said I think a string inverter with a V configuration SE/SW would be a nice solution.

[@tomrausch7014]

Caveat…I know NOTHING about solar, but what you say makes sense. I wonder what your solar panel output would be like IF you could make the west facing panels flip able, that is face the east in the morning and west in the afternoon. Gone would be the snow issues in the afternoon. It doesn’t seem to be a huge engineering problem if you manually flipped them.

[@ProjectsWithDave]

I like the idea, I hadn't thought of that. However, I wouldn't want to take the time to do it manually and at this time I am avoiding automation. I think bifacial panels would be a simple way to "flip" them. Thanks for the idea!

[@tomrausch7014]

@@ProjectsWithDave Too bad I really like to see that OR a electro mechanical west/east flip system that stores panels vertical at sundown until just before sunrise to keep snow off so panels can start collecting photons without having to warm up and melt off snow. I wonder what the amps made for the system would be then. Hmm, seems the old grandfather clocks used a weight system to run that didn’t halve to be wound every day. If it could be figured out with some kind of cam system and windup weights it might work. My father back in the ‘60’s pre-computers came up with a plastic cam that cycled a machine on and off saving the company money and earning him and mom a trip to Hawaii. Though I believe solar may be the way to go in the long run, it seems like it’s not there yet. I’ll subscribe and see what other ideas you do.

[@ookinekko]

Great video Dave! Lots of nice data

[@ProjectsWithDave]

Thanks!

[@hiyahDotNet]

In FL we tend to have clear mornings and afternoon thunderstorms during the summer so east turns out to be slightly better than west, all other things being equal.

[@ProjectsWithDave]

Makes sense, pays to know your own weather patterns. The average daily data that is used by online calculators doesn't take that into account.

[@testthewest123]

I wonder if just using some batteries and bigger inverters is more prudent. The total production drop off is pretty big for the west facing panels.

[@ProjectsWithDave]

Batteries and smaller power ratio's significantly increase the payback period of the system.

[@plnthrd]

I started a similar situation on my system and it works great in the winter....I doubt it will do much in the summer though

[@jantschierschky3461]

Well I live in western Australia, Perth. Have a 2kW system. Average production in winter (we have no snow, but is our wetseason) 9kW/day, in summer Average is 14kW/day. Problem here it can get very hot so even on a sunny hot day I get 14.4, however if moderate can get 16kW. My panels only face north (southern hemisphere), when I renew system I will also get panels east and west.

[@ProjectsWithDave]

Thanks for the info! Sounds like heat is a significant factor for you.

[@jantschierschky3461]

@@ProjectsWithDave absolutely, it can make 2-3kW difference, Days over 40C, best temperature seems to be up to 27C, than it can do even 17kW in a day

[@williamlabarre4755]

How about power inclining? Optimize the facing angle to the sun with an essentially bottom placed hinge, tilting to provide a normal surface to the sun during the day. Could always be combined with the results of your panel facing study.. guess ultimately an actuated panel covered igloo shape..

[@Dave5843-d9m]

Why not use a smaller array that follows the sun? Alternatively mount it on a track that slowly turns. The turning speed can be timed from 45 degs East to 45 degs West over 12 hours.

[@csf1757]

As I have read, nowadays more panels = cheaper than fewer panels with motors. And, the motors break or need adjustment regularly.

[@guytech7310]

My recommend for a test is to create a chevron with the array, such that half of the panels face south-south-east (perhaps at a 10 to 20 degree angle) and the other half south-south-west. I believe this would flat out the production curve & provide over all more power per day. The issue is that having the panels face dead west is that those only producing power for just a few hours per day. You could try a small chevron using 2 or 4 panels in front of your main south facing array to see if it helps. Besides clipping I see the battery bank capacity. Once they fully charge, any energy your not using for your load just gets wasted unless your dumping excess into the grid. If you can increase to total hours the array is generating power it might be a better option. With more hours of production but at a reduced peak power, the power can be use longer to power your load & still charge your batteries with less unused power generated. This might also help with weather, for instance if you have a lot of overcast during part of the day, the extended hours might allow you to collect more power if the overcast isn't present in the morning or afternoon. Also with Chevron layout I think it will address the snow melt issue since its more likely to melt quicker.

[@ProjectsWithDave]

Thanks for the proposal.

[@masterdebater8757]

I like this idea very much if i had the issue the content creator has it would be for me 15degrees either side of 180degrees (due south) so half at 165degrees and half at 195degrees but i think that would be a bit to much total loss. If "pvwatts" calculator is accurate. (0.o) Maybe break angle 4 times at 7.5 degrees each and get best of all seasons and not get the clipping. Depending on the system maybe he could use the DC side and install another load maybe a project using a DC/DC convertor and small battery bank for a sort of hobby anything to divvy off some of the VA before it gets to the invertor. Maybe a dump load water heating set up on a timer with another timer set for charge cycle right when the clipping normally happens. My gears are turning lol.

[@serevinvukele8046]

More panels are cheaper than adding a battery at the moment. Just for comparison the UK is at 50+ degree latitude whilst Ohio is at 40 so you are in a better position than others.

[@Llyrana7]

To 22:30 - why don‘t you put 2 Arrays (east + west) not on swiveling / rotating basements? You could rotate them in the winter both to the south and to east/west each in the summer to harvest more sun energy…

[@EthanTheBarton]

As a telescope enthusiast I am definitely reminded of how a equatoral mount works and how one could take that concept and adapted to solar array setup... But I think it would be cost prohibitive.

[@peterbreis5407]

Don't need anything as expensive as a precision telescope equatorial mount. Anything that rotates will do, a plate on ball bearings or a simple car wheel as base would do, moved very slowly by a highly geared small electric motor controlled by a small light detection panel. At the end of the day, it would hit a switch that sends it back to the morning position. Given the small gains to be made by eastern/western orientations, the setup would gain more by having a seasonal tilt to point perpendicular to the sun. The benefits of that are easy to calculate, entirely predictable and require very simple mechanics with only a tiny motor to make it work. Ideally you would use a large thermal mass, like water or masonry, within the building to store heat/coolth, gathered however you want, then use a heat pump from that to run air conditioning or heating to balance variations.

[@ChristopherGaul]

Great video. I learned a lot and got some good ideas for my own projects. One question. Since you're in a northern latitude, why not face the extra panels southwest rather than straight west? I would think facing them straight west would only make sense for a near equatorial installation. Oops, should have waited until the end before I started typing. Glad you caught it too. Really hope you do test southwest as well and show us that data! Thanks!

[@brianb9410]

Very well done Dave!

[@cowboyboots9901]

Now what happens when you rotate 2 panels South/East and 2 panels South/West. You cushion the losses during peak Southern light and pick up dawn and dusk light

[@TallTexasGMan]

This is very interesting and helps justify the reason for solar tracking arrays. One thought, you likely need to have the West panels nearly vertical so they capture the long rays of the sun. Just a thought.

[@ProjectsWithDave]

More vertical actually reduces the performance because it captures less of the light earlier in the day.

[@TallTexasGMan]

@Projects With Everyday Dave Yes that is true, but if you want to capture the setting sun. During a time where your primary panels are not capturing peak efficiency, use these to boost the capture.

[@Birchall88]

Have you considered adjusting the pitch on the west facing array? Increasing the pitch slightly compared to the south facing array may increase the direct solar radiation absorbed. I will be interested in the effect of facing the array SW (and SE) rather than due west. I suppose the balance depends partly on your usage load distribution.

[@ProjectsWithDave]

Historical data shows a flatter angle produces more energy for the west facing array. I'm grid tied, so my load is essentially constant.

[@echoeversky]

What would be the impact if all your panels were actively solar tracking? How much cost would that take and how much more efficient would your panels be?

[@ProjectsWithDave]

Tracking is more efficient but also much more expensive. It's more cost effective to just add more panels.

[@DigitalArchmage]

have you also considered not facing due west, but southwest? There may be a more optimal direction to point the panels for the unclipped regions.

[@Nevir202]

Okay, but what if you made this small array attached to a winch on the western most side? In the morning lift the bottom up till they are facing east, flatten them around noon and drop them back to west facing in the afternoon lol.

[@ipvisioncctv]

Thanks for sharing . 👍 I did also the same and to be honest the matter about consuming that extra at the time we start cooking or things like this I better this orientation. Thanks

[@AramisWyler]

This is a great video, ty. I'm going to have to go through your channel to see what drove you to make these decisions. My first thought was to wonder why the clipped power wouldn't go to battery, as it would not need inverted. But now I see that there doesn't seem to be a batter bank involved here at all. So I'll go look at your other videos and see what's up.

[@ChuckD59]

Thanks Dave. I'm in the process of speccing a 17-20 kW ground mount array right now here in upstate NY. Your deep dives into the solar system's workings has really been a big help. I'm just gonna throw this out there, something that crossed my mind watching you; would a bowed rack be the ideal? Putting aside the challenge of building one for 40+ panels, I couldn't help wondering how that would perform. Thanks for sharing your work.

[@ProjectsWithDave]

Good question. Aside from the complexity of building such a rack you have to consider the type of inverter setup that would be required to take advantage of such a system. A string inverter would not do well with every panel putting out a different amount of power. You would need to use optimizers or micro inverters for that so that each section that faces a different direction is controlled separately. Creating a V with one section facing SE and one facing SW or even SSE and SSW would give you much more freedom in inverter choices and dramatically reduce the racking complexity and probably give you a better result. The curve setup will still be overpowered at noon. Hope that helps.

[@ChuckD59]

@@ProjectsWithDave Yes, the electrical bits are what I'm not clear on. I'm going with either micros or optimizers since we will have about a 200' run to the house. and AC travels better than DC. Thanks, and nice work!

[@ProjectsWithDave]

You should be able to make it 200' with 240VAC, but you want the highest voltage you can get to reduce your losses. You should be able to achieve 400 to 500VDC with a good string inverter. Higher voltage means lower current for the same amount of power. P=V*A

[@James-os6uk]

Great video! I am still a solar rookie with 24 panels currently and another 12 I will be installing this spring. Look into the APsystems Qs1 Microinverter. You can connect 4 panels to each one and they are quite inexpensive. They clip at 300 per panel so 1200 over all. I run mine with 320w panels.

[@ProjectsWithDave]

Thanks, I'll check it out.

[@vincentrobinette1507]

one thing to consider, is that solar panels degrade based on the total insolation over their lifetimes. By avoiding clipping by moving them to a different angle, you're increasing the calendar life of the panels, reducing the total levelized cost of energy. You will get more energy from the panels over their lifespans, it will just take longer to get it. In my case, I'm gong "roof top", so I really don't have control over the angles. I'm running an enormous 16,200 watt array, 27 panels facing east, 27 facing south. (300 watt, 72 cell polycrystalline panels) I'll be connecting each 9 panels in strings, to my continuous scan maximum power point tracking circuits, 3 strings East, 3 strings west. All panels in each string will be on the same plane, I'm NOT using DC optimizers. What I'm looking for, is a longer charge cycle with less current, on my Lead Acid battery array. (67 kWh) That will help with the charge acceptance efficiency, and allow better absorption charging. I'm choosing not to use optimizers, because, with all panels per string on the same plane, I don't feel that optimizers will give enough extra output, to pay for themselves over the lifetimes of the panels. They may not even make a big enough difference, to cover their own electrical losses. I would only recommend them in situations, where some panels may be shadowed by features of the roof, or trees, or utility poles/lines. That way, you lose part of one panel, not the whole string! In my system, the MPPT's will merely keep the current flowing, and the anti-parallel diodes in the shaded panel will just merely bypass it. I'll get lower voltage at the same current, effectively losing only the one panel. I'm going grid autonomous, NO grid back feed. I can draw from the grid when necessary, but, cannot send excess back. That's why the huge 24 hour battery.

[@ProjectsWithDave]

Nice system!

[@MattOGormanSmith]

Your data is valuable for people planning a roof installation, but with all your open space I would invest in a ring roller to make a circular rail and have the whole array tracking the sun in alt and azi. Some metalworking skills would vastly reduce what you're spending even on static frames.

[@creatorgutz3376]

Rather than having additional panels (plus supports) facing east and west, wouldn't it be more efficient to use two axis tracker?

[@ProjectsWithDave]

It might be the most efficient use of solar panels, but it would not be the most efficient from a cost perspective.

[@AvocaSingleTrack]

You should try it more Southwest instead of dead west ...and the sun is at a lower angle later in the day . Your angle looks like you should tip them up a bit higher.

[@ProjectsWithDave]

You can watch the SW update here: kzbin.info/www/bejne/gGjbn4xuaaibZ6c

[@Paul-cj1wb]

Yes, place 3 panels facing SW an angle (45 degree or close to it) rather than straight West. But why not also place 3 facing Southeast to max your morning output in the winter like others have suggested? Just capture the extra juice in more cheap LiFo batteries for cloudy days or charge your EV if you have one?

[@ProjectsWithDave]

In this video, I was just testing out the concept using west facing panels. In my latest update on the project, I show an "optimum" case of facing panels SSE and SSW. You can see the results here: kzbin.info/www/bejne/gGjbn4xuaaibZ6c

[@Paul-cj1wb]

@@ProjectsWithDave Just saw it. Thank you for letting me know. Nice video. Only saw the SW facing extra panel. Can't wait till you add the SE facing panel(s) and the more angles to see the results of those tests. It's great how people like you show this so that more and more people can see they can do it for themselves. Not sure how far you are from a main road, but I can see people like you adding a little more solar (well, more than a little) and cheap LiFo batteries and install their own EV chargers for rural communities and make a little money on the side as EVs begin to take over. I remember seeing this farmer in England who had a 2MW wind turbine installed in his farm and supplied all the extra energy for his community/small town at half price. With his turbine and their solar plus some batteries, it was all the community needed. He financed it, cost around 2 million, and within a few years (forget how many) he had made all the money back. In fact, in the old days, some people would install gas stations on their property to accommodate those rural communities with less access to gas stations to made money on the side.

[@ProjectsWithDave]

That's an interesting and fun idea! I don't think it would work in my location, but I can see how that could become a strategy for getting additional charging stations around the country. Someone should setup some type of franchise for people to collaborate on that idea.

[@prospermandizadza6595]

I would say you geeked it out really well. Nice video.

[@ProjectsWithDave]

Thanks!

[@a..d5518]

That was one very informative video, thank you for all your work. I know this is late to the game, but, with all the data you have, would building an array on an arc from east to west, with a slight angular change every 2 panels, with the south facing being groups of 3 or 4, be the way to go for a new build? Especially in the same scenario that you have with the array being at ground level as opposed to a roof mounted system. I realize that would require more precision when placing your uprights, and that there would be gaps at the bottom of each grouping as they continued around the arc. Just thinking as I type...

[@ProjectsWithDave]

Ha, that's funny, you think just like me. I thought about the same thing, however as you said the structure would be complicated and would have gaps at the bottom resulting in a very inefficient layout. After some thought, I abandoned the idea based on practicality. Thanks for the idea!

[@a..d5518]

@@ProjectsWithDave I was pretty sure that idea had crossed your mind as well, thanks for your reply. Look forward to seeing your ongoing results. Of course, the solution to this quandary would be wedge shaped panels, with the narrow end at 60% the width of the wider end. Again, just a mental exercise. Stay Safe Stay Well

[@ApemanMonkey]

@@ProjectsWithDave Gaps actually help lower the wind loads, plus you seem to have enough space ;)

[@rustyloads1361]

Off Grid I run a 9,000 btu ductless mini split 24/7 July thru November at sea level in southern AZ. It takes 2-3kw to start it and 1.5kw to run it full tilt. Overnight is the tricky part. I have a diy lifepo 24v 700ah, univ. of youtube battery set up, cobbled together that runs the AC and three compressor fridges overnight. I use ten 265w panels facing east to catch the morning energy and get a jump on the day. Ten facing south to help catch all the midday energy and ten panels facing west to catch every last drop of energy before night. Thats 30x265w for almost 8000watts of pv. Seems like a lot but used panels are cheap or use to be when I bought these. This pv set up easily runs the AC and recharges the 700ah battery on cloudy days. Chemtrail days are a problem, that shite really blocks the pv energy.

[@ProjectsWithDave]

The nice thing about used panels, is it can make economic sense to place them in a less "efficient" orientations to broaden your input time throughout the day.

[@rustyloads1361]

@@ProjectsWithDave Ya it can. My Victron 150/100 charge controller, max’s out at 100 amps. If I set up all 30 panels facing south, solar energy is wasted and I cannot recharge the batree bank AND run the load. By facing 10 East, 10 West, and 10 South, I can capture most all the available solar energy, run the load 24/7, and recharge the 24V 700ah batree bank. Side note: As an experiment I hooked up all 30 panels, all facing south, to the batree bank bypassing the charge controller. It charged very efficiently, best ever. I did have to baby sit it when batree voltage reached near capacity 28v-29v so I could cut off panels. In effect, I became an unlimited amp, manual charge controller. Cheers

[@chickeandtech]

You have all the space possible to make an installation with solar tracking panels that track the direction of the sun constantly and rotate with it... you could produce even more energy and clip even more compared to the fixed mode.

[@ProjectsWithDave]

Yes, I just don't want to invest in a tracking system, it won't pay for itself in a reasonable amount of time.

[@taylormills08]

Fantastic video. A lot of work involved. I think you might be best off to split them evenly on two racks. One slightly southwest and one slightly southeast. Looks like your system is working fine though.

[@ProjectsWithDave]

Thanks! You're right my system works fine as is, I just can't help but try and see if I can make it better : )

[@jonasgranlund4427]

Really good and interesting presentation. One thing to consider could be to have everything in South and an inverterer that just barely handle the full load and see how inefficient that larger inverter is during the periods where the sun is less then half of inverters output.(how many kwh will you loose per year compared to the clipping that is happening now). I am thinking of buying a solar system now, but I am thinking about maxing out solar from panels towards south and have a battery storage so I can use the power when I need it and also sell back to grid during the most costly hours. But even if I DIY a LiFePo4 battery it is quite a bit more expensive with a battery solution.

[@ProjectsWithDave]

Right, it is very hard to make any battery solution pay for itself. If you are doing batteries it is likely because you want to have emergency backup or a strong desire to be off grid.

[@VarroTigurius-u1f]

Or you could take a small number of panels and put them on a suntracker stand to always collect their peak power.

[@TheZinminjr]

This is a dumb question because I’ve just gone down the solar rabbit hole in the past 48 hrs: 1. Why didn’t you simply buy a DC battery large enough (piggy back 2) that could store all your “clipping”? 2. Since you have so much land: why didn’t you install (DIY) dual axis solar tracker for $100 for maximum coverage on your original?

[@ProjectsWithDave]

Batteries and trackers are both expensive relative to the power saved or produced by them. There is no $100 tracker for a 10kW solar array. The most watts produced per dollar spent results in the shortest payback period. My system payback is less than 6years.

[@kirbythomas5468]

What if you add another inverter and put half of the panels on each one would that reduce the clipping and allow you to optimize the overall output?

[@ProjectsWithDave]

Another inverter would recover the clipped power, but the goal was to minimize new investment.

[@DennisMarwood]

What about a mount base that could be rotated? Then adjust it monthly. It would need to cost less than additional panels I suppose.

[@ProjectsWithDave]

Exactly, the cost has to be less than more panels and it usually isn't.

[@kkarllwt]

Ask a garage to save some throw away wheel bearing sets from some larger cars. The may be shot, but you are only going to move then 15 degrees a few times a year.I assume you can weld, or know someone who can.

[@workwillfreeyou]

Great Channel for solar Dave! I've seen a plant near me that has their panel "Track With The Sun". I'd think this would be worthwhile. Your thoughts? This technology is probably getting cheaper by the day.

[@ProjectsWithDave]

Tracking technologies are getting cheaper and better, but so are solar panels. I haven't seen something yet that I thought would be worthwhile for the residential user unless you were very limited in space.

[@m88k]

Are the west-facing panels due west? I'd think peak generation would have you angling them somewhat southwest.

[@ProjectsWithDave]

Yes, they are due West, and at least for the winter, SW would be better according to the data I have collected so far.

[@m88k]

@@ProjectsWithDave Yeah, I wrote that up before getting to the end of the video. Have you played with the NREL pvwatts calculator at all before moving panels around? It'll produce handy predictive hourly numbers based on a nearby measured insolation pattern.

[@ProjectsWithDave]

Yes, I use it a lot. It's a great tool!