If you’re mounting solar panels, everybody knows the drill, right? Point them south, angled according to latitude. It’s easy. In a video which demonstrates that [Everyday Dave] is truly out standing in his field, we hear a different story. [Dave] has a year’s worth of data in his Solar Panel Showdown that suggests there are good reasons to mount your panels vertically.
Specifically, [Dave] is using bifacial solar panels– panels that have cells on both sides. In his preferred orientation, one side faces South, while the other faces North. [Dave] is in the Northern Hemisphere, so those of you Down Under would have to do the opposite, pointing one face North and the other South.
Since [Dave] is far from the equator, the N/S vertical orientation beats the pants off of East-West facing panels, especially in winter. What’s interesting is how much better the bifacial panels do compared to the “standard” tilted orientation. While peak power in the summer is much better with the tilted bifacial panels (indeed, even the tilted single-sided panels), in winter the vertical N/S panels blow them out of the water. (Especially when snow gets involved. Vertical panels don’t need sweeping!)
Even in the summer, though, there are advantages: the N/S panels may produce less power overall, but they give a trickle earlier and later in the day than the tilted orientation. Still, that extra peak power really shows, and over a six-month period from solstice-to-solstice, the vertical panels only produced 77% what the tilted bifacial panels did (while tilted single-sided panels produced 90%).
Is it worth it? That depends on your use case. If most of the power is going to A/C, you’ll need the extra in the warmer months. In that case, you want to tilt the panels. If you have a steady, predictable load, though, having even production winter/summer might be more to your liking– in that case you can join [Dave] in sticking solar panels straight up and down.
These results probably apply at latitudes similar to [Dave] who is in cloudy and snowy Ohio, which is perhaps not the ideal place for solar experimentation. If you’re not an Ohio-like distance from the equator, you might find an East-West array is the best bang for the buck. Of course if you really want to max out power from each individual cell, you can’t beat sun tracking regardless of where you are.
Some of us live in the Southern hemisphere.. ;)
For USA people, there is only one country in the world. Their.
Nope, for them, the world is their country.
Nope, their country is shrinking every day.
the US is very consistent throughout and very large. we can’t take a day trip to a dramatically different locale like Europeans can.
I live in the gulf south.
Two weeks ago I flew to Las Vegas for a friends bachelor party.
I have a two day business trip to Portland on the books for the 15th.
and I just booked aa ski trip to colorado in November
the US is very inconsistent throughout and very large. we can take a day trip to a dramatically different locale like Europeans can, but it usually requires a cheap flight.
Whoa there, Leonardo. Ignorant people abound everywhere. About half of Americans travel externally. Many appreciate other places.
+1
Yeah how can people forget about the US military? They travel all over the world as you say.
“War is God’s way of teaching Americans geography”
Not mine, but first time I read it I couldn’t resist a good laugh, then from the 2nd on it made me think.
” [Dave] is in the Northern Hemisphere, so those of you Down Under would have to do the opposite, pointing one face North and the other South.”
Deliberate humor or not ?
Hopefully, they didn’t explain the East/West orientation for oriental hemisphere.
Either that or the author is an idiot.
I know which I’d prefer to believe.
+1 :-)
You can lead a horse to water, but you can’t make him laugh.
Thanks for brightening my morning, Tyler.
yea…I was going to post as well – ” is in the Northern Hemisphere, so those of you Down Under would have to do the opposite, pointing one face North and the other South.”
I think many bifacial panels have different power ratings for the two sides, so there is a side that needs to be pointed a certain direction.
Everything’s opposite in Oz :-)
that reads as someone who knows what they are talking about, and joked.
However the first para has me wondering about that: “Point them south, angled according to latitude. It’s easy.”
Should be, “Point them towards the equator….”
once you’re below the equator, just use a negative angle
Point ’em where the Sun is? …or take an average.
You still need to point one face south and one face north though..
One word: wind.
I’ve not watched the video. Keeping large sail like panels vertical in areas with high winds for 20 years will require some major anchoring and very deep foundations. And the risk of shadows across multiple cells from guy wires means that they can not be used.
I attached mine to a pre-existing vertical structure with large sail-like panels, a fence.
It really won’t be that bad unless you get very large – your average low effort built to a price housing estate fencepost is only foot or two deep in dirt, maybe a little rubble backfill and they last well enough, maybe not 20 years but a good while. Switch up to doing it properly with the concrete fenceposts…
Also just how high winds are you talking about? As the difference between panels mounted tilted or vertical on the ground for wind catching and forces on the mounts could end up being much tougher to survive with the tilted panels acting like an aerofoiil and actively lifting up while the vertical panels just create a dead air space.
I’m not as much worried about the posts, but the panel itself getting rattled to pieces with the wind. It’s a sandwich of glass with fragile wires in between, after all.
can’t say i’ve tried it but i’ve helped sling panels before and they are typically pretty mechanically stable. it’s tempered glass fairly well-anchored to the metal frame. so long as the frame is well-supported, installers can even put their weight in the center of the glass. what i’m saying is, i can’t hardly imagine it rattling. i know they’ll pull a post out of the ground but rattling seems unlikely.
What I’m worried is when the post or the panel inevitably comes loose, the panel will start to flap and flex with the wind, and that will grind at the mounting points and edges where the stresses are concentrated. The edges of the panel will chip or crack and delaminate, moisture gets in, and the panel is ruined after a couple years.
If they can’t take that they are not suitable for regular use at all – the very nature of them is to be pelted by hailstone, pulled at by high winds etc. They are not impervious, but they are really not fragile.
It’s one thing to be pelted by hails, and another when the entire panel acts as a sail in gusty winds and puts significant forces on the mounting points.
I expected installing them kinda like this https://en.wikipedia.org/wiki/Crinkle_crankle_wall?useskin=vector (zig-zag pattern) would solve (most of) that.
that’s true but anchoring is already the biggest part of installing panels independently of a building. when my electrician friend went into solar installation, he had to buy a bunch of digging equipment and now orders concrete in whole numbers of yards. he’s also gotten to clean up after people (and distribute free dented panels to his friends) from installations that were improperly anchored and blew over.
i mean if you think about it, an angled sail puts a ton of force already. a straight vertical sail is only marginally worse.
Just attach the solar panels to wind turbines, problem solved!
/jk
With that out of the box thinking, you’ve got upper management written all over!
” [Dave] is using bifacial solar panels– panels that have cells on both sides. In his preferred orientation, one side faces South, while the other faces North. [Dave] is in the Northern Hemisphere, so those of you Down Under would have to do the opposite, pointing one face North and the other South.”
It’s the same orientation.
Figured that was a joke, right?
whoosh
Welcome to the joke. We hope you like it here
1 ….. i thought it was a great joke (unless it was an error). Not nearly enough humor on Hackaday :(
Look up.
I couldn’t figure if this was a joke or if the panels had a “high illumination” side and a “low illumination” side.
Otherwise it’s a bit of a no-brainer that even if you’re pointing the extra ones away from the sun, twice the number of panels produces more power… imagine the benefit if you doubled the number of panels and pointed them all towards the sun!
bifacial solar panel cost less than twice a standard solar panel. So this experience proves they are actually better than a standard panel. For them to be economical depends on numerous factor, but at least, now you have a number to decide upon, if they are 30% better but cost more than 30%, it’s not worth it.
Unless you need reliable power output greater than can be achieved in the space you have otherwise – in which case they could be only 20% better and cost 100% more and still be worth it for some instals – not every solar instal has the same goals or available space.
For anther example you can get little micro MPPT inverters that go on each panel individually and get strung together for many many more points of failure but a system that is overall more productive in most cases – costs a fair bit though (at least last time I did any looking, which was some years ago), so I’d generally not suggest they are worth it even when your deployment would certainly benefit.
There are solar cells that have the current collectors embedded “sideways”, so the same panel can be illuminated from both sides. The original idea of those was to put a reflector behind the panel to bounce back any light that manages to pass through, but it was never economical to make them. There were some other problems as well, but I forget.
So there are true double-sided solar panels, though rare, and then there are those panels with cells on both sides.
It depends on the panel; it appears that [Dave]’s particular panel is indeed symmetrical, but I have seen panels with a “high” and “low” side.
I did intend that line as a joke, for the record.
Was the “outstanding” typo a joke too? Proof that he’s out in his field, standing? I chuckled, regardless.
Yes, that’s a very old play on words.
I guess this North/South or South/North orientation only really pays off in the snow. For most of the planet, you are wasting your time putting 50% of your capacity into permanent shadow.
Not totally true – Up here in Finland, during the summer the sun can be in the south from early morning to early evening and in the north the other side of the day.
I have two panels on the roof of a storeroom/workshop/shed with two panels, one facing due south, the other not-quite due north as it faces the big gap in the trees. Both panels are mounted vertically too.
The system works very well.
No it can’t. Even in northern hemispheres, the sun rises from the east and sets to west. If you’re up above the arctic circle where the sun never sets, it starts from north, circles around to south, and then goes back north. In either case, at 6 AM the sun is shining from east, 12 AM it’s south, and 6 PM it’s west, 12 PM or midnight it’s in the north.
If you calculate where the sun would be at 9 PM in July in Helsinki, it would be about 6.5 degrees up from the horizon north-west, and when it’s so low in the horizon the light is passing through a lot more air, which makes the direct brightness about 20% of what it would be in the middle of the day. The light has to travel through hundreds of kilometers of air and whatever is suspended in the air, like water vapor and air pollution, which is why sunsets are red.
For the same reason, when the midnight sun is in the north, the actual direct brightness is reduced to 2-3%. So, if you place the panels north-south, any time the sun is facing the panel from north-west through north, to north-east, between 9 pm to 3 AM, it would be too low in the horizon to actually do much.
I mean, northern latitudes. There’s only one northern hemisphere.
OP said “only really pays off with snow” and “putting 50% of your capacity into permanent shadow”, which is not correct as alloydog pointed out- anywhere north of the equator between the spring and fall equinox the sun will rise north of straight east (90°) and set north of straight West (270°), the effect being more exaggerated the further north of the equator you are. I’m in MI, USA a little north of 43° latitude, at the summer solstice the sun rises at 56°NE and sets at 304°NW and the sun spends >6 hours per day north of straight east or west, with over half that at greater than 15° above the horizon, meaning you’ll still get reasonably good production. All in all it means for at least 4 months out of the year a north facing panel would receive ~1-3 hours per day of sunlight at a good production intensity. I’m sure that would be even more exaggerated at 60° north latitude in Helsinki.
Mind that the panels don’t get full power when the sun is off-normal from the panel. This is because of shading by the collector wires and partial reflection inside the glass, total reflection off the glass, etc. Essentially, the panel has a “viewing angle” with some percentage points loss of efficiency for every hour the sun is offset in angle. This is in addition to the fact that the panel covers a physically smaller area towards the sun when it’s at an angle, and therefore receives less power.
So when the sun is north of east or west, it has to be far enough north to face the panel or it just won’t do anything, but the further north it goes the lower in the horizon it gets, so that won’t help you either.
So, of the 1-3 extra hours that you might catch, most of it will be at low intensity or from a bad angle, so it may not contribute more than 5% extra output per day.
Not really – the scattered light that will reach the shadowed panel is still meaningful amount of energy capture and the cost of the panel itself is almost nothing compared to all the other costs – the mounts, the inverters, and the usually required planning permissions and qualified electrician ends up being the lions share of the cost.
So while you don’t get the same return on investment as if you could mount it pointing more to the sun on the panel alone it will still be a meaningful gain for relatively little cost, so if you have the money for more but not the space or money to cover a wider area with primary oriented panels…
not watched video either, but the graph that is visible indicated a january day, when the sun would be very low in the sky
You won’t believe it, but in 12 minutes of video there’s (gasp!) more than one graph
I would try adding a mirror for the back side.
The show did ;)
Snow, … auto correct
That same YouTube channel has other videos where he tried exactly that.
well. im curious how this scales without making a interesting high building in the process. I saw a similar experiment here in the netherlands in passing by to my work place, but i have no idea what the conclusions were.the group of panels were quite close together, so only the non obstructed panels would have a optimum effect.
i have two 500wp panels installed like a short fence. around 1000kwh/year with peaks at 4.6kwh/day. Setup costs euro 400,- including inverter (with wifi)
I’d like to see more data on this idea, not just one sunny day in January. For example, how do the orientations compare on cloudy days with more ambient sunlight?
If only there were a 12 minute video linked at the end of the article with dozens of graphs of different days throughout the year appearing in it 😜
The main problem with vertical – apart from the wind – is you’d need a nice empty farm to put them in..
I suspect vertical would also work better at a higher latitude..
I’m in Aus close to the tropic line – so in summer the sun is straight up – and what I’ve done is put panels on the east, west, and north. So at the spring equinox I get power from 6am till 5.30pm. And from 8am till 4pm more power than I can use..
If only we could have a breakthrough in batteries I could get rid of the grid…
No you can’t. (At least, not without changing your life habits). To get rid of the grid, you’d need to install panel at an exponential growth and it’s unsustainable. See https://www.construction-physics.com/p/understanding-solar-energy for a computation example.
Odds are your personal life hasn’t seen an energy consumption increase in decades (for the established industrialised nations anyway) – the modern computer/phone/TV is generally at least one of better and more efficient and usually both. Your AC/HVAC systems in a nation that actually needs them have likely improved in efficiency too, even if its just better building standards like adding insulation and replacing old very leaky windows etc.
So as an individual the only thing you need to get off grid is an energy storage capable of smoothing out the supply and demand curves and an array of solar large enough to have captured enough energy – which is a balancing act between the two as over the longer weather cycles your solar array doesn’t have to be generating enough every day for that days use if the energy stockpile is large enough, or if you have enough generation capacity you can technically ditch the battery concept pretty much entirely as even on the worst day a PV panel is generating something, add up enough of that something to match your demand and you only have to worry about overnight energy storage – which for some folks means effectively no worry at all, as you are asleep, don’t need AC, with the door closed your fridge/freezers will stay suitably cold (you’d probably need the chest type that holds the cold air in better and perhaps to overdrive them a touch during the day), and your essential devices all have internal battery anyway.
Obviously I don’t think either extreme actually makes much sense, and honestly think a grid connection is usualy worth it – your otherwise wasted generation capacity can be sent to other (be nice if you got paid better for it, but even if you got paid nothing its a net gain for your society and you can be on the receiving end of others generosity while you are under the storm cloud)…
But to get rid of the grid connection as an individual isn’t all that impossible.
Terence Eden did some math
https://shkspr.mobi/blog/2025/09/how-big-a-solar-battery-do-i-need-to-store-all-my-homes-electricity/
Interesting read, and rather inline with expectations. Small European homes just don’t have the roof area to pack enough panels on for the battery to get sensibly small to be good all year as a rule. Though I’m certain it can be done – I think just a Vehicle 2 house capable car and charger would be enough for us here in a small European home, might need two cars worth for good measure (as assuming most of the time one car would be home overnight in particular is safe, where falling back to just the existing tiny house battery too often…).
We do have a really good location for solar generation which really helps with reliable output across the year though – roof is very south facing and in two parts – so the upper roof is at a better angle in the winter while the flatter one is actually quite good for peak summer (neither are of course solar tracking level of optimal nor were they actually designed with solar generation in mind, its just how this old house happened to get built and extended).
Not however got years worth of logs to look at (not got round to setting up logging so all I have is the bills), so this is largely just guess work looking at instant consumptions and generations whenever I bother to across the year to help paint the fuller picture.
yes I can, I only need storage. I’m in the tropics – I don’t need the grid at all (at this time of year) from 6am till past 5pm, I just need enough stored for overnight.
I even get more power than I can use on cloudy days – again would only need a battery for overnight/ smoothing.
The only days I don’t get enough aggregate power is heavy clouds and rain all day… So again, need a battery big enough..
How much power are you using? I have ~60kWh of LiFePO4 battery storage that takes up ~44cm * 74cm * 108cm, total cost was around 4000USD for the batteries. That with ~10kW of panels has been enough to allow me to never need grid power throughout the year at ~1200kwh usage per month, and I’m in snowy cloudy Michigan USA.
Tell us more: Are you heating with gas? How many ft^2 etc.?
I grew up in Michigan and have always maintained that if solar can work there year-round (with its maritime climate and semi-arctic winters) it will have crossed some sort of tipping point.
While I agree that all the energy sources you use in the house matter in a discussion of this sort of thing most of the time when strictly talking electricity its not really relevant – Even if you are still using gas for something does it really matter to the value of a solar install to you?
I’d have to argue some gas power in use is not relevant at all, as long as you are not going ‘all solar electric grid free’ by paying yet more money on infrastructure and your gas bill to move onto using the petrochemical generator for most of your needs – you already had a gas tank/pipe and have been using it for heating/cooking/hot water, those bills probably don’t change, as your electric bill goes away (or even turns into getting paid) unless you really really want to go the extra mile. At least not immediately – as to do all costs more money, and likely a good amount of it – about the only cheap option to add on to your solar install is an immersion heater for your hot water (which is probably just a smart controller that dumps the excess solar energy your setup generates into the existing immersion heater backup to reduce the need for gas). Moving to ground source heatpump at the same time is likely too expensive to stomach in one sitting for most folks, but probably required if you want to turn solarPV into heat in most places.
Yes, I’d do that in a heart beat if it was available in Aus. But like most things we pay a “Australia Tax’ on things ie we are a small market, a long way from anywhere, and that is without local taxes.
60kWh of battery here would cost 10 times what you have suggested – if it was the price you are suggesting I would have a lot of batteries… Put a link to where you got them from (though I’m sure they won’t ship to Aus..)
Although a joke, the backside of the panel is less effective, so the panels should indeed be oriented the other way around south of the equator.
I am curious to try a bifacial up here in the snow, but in the winter the sun never rises above the horizon, so it would be spring/fall for me (think northern part of alaska)
But how about the wind issue ?
It will collapse with the first storm…
Dispense with the north side and re-enforce the panel appropriately.
Not if you anchor it properly.
Most of our environmental monitoring stations use solar-panels mounted vertically and have ground anchors hammered about 75 cm into the ground. In 13-years, the only ones that have fallen over have been hit by mining trucks.
see above + ZigZag pattern
Solved problem, just look to privacy fences that don’t collapse in storms.
I still see fences collapsing, except the one made of hole…
How hard is it to just write, point the solar panels in the direction of the equator with the angle being proportional to your distance from it? That is the formula isn’t it, for a standard install?
Writing is easy, it’s the remembering that is hard. Also, That is only “the formula” if you have experience installing in both sides of the equator, otherwise it’s always been one or the other. I understand why you are miffed but please understand that it’s on of those, “oh, yeah, you’re right,” type of things that you don’t think about until someone says it.
So, should you point to the equator or with the angle? 🤣🤣🤣
Proportionate from what to what?
How hard it is to not tell two contradicting things in one sentence?
A study from Aarhus University from this year, looks into the same topic:
https://www.sciencedirect.com/science/article/pii/S2772427125001664?via%3Dihub
Whos going to be the first person to mount them on their roof like this? :)
Record-breaking: World’s largest vertical solar rooftop built in Norway https://share.google/sUdmzOLJLucS1lKtc
‘share.google’
Good luck with that.
Putting 6kw onto a 4 in 12 slope steel roof facing directly west. I’m in central Florida, and the hottest part of the day is the afternoon. I get full exposure of the panels from sun-overhead to sunset. I do see a problem mounting the panels vertically – we get hurricanes here, and when we do, every fence gets knocked flat on the ground. There’s also a problem with wind-blown debris for ground mount vertical panels. They aren’t impact glass, so even if the solar fence stays up, the panels will likely be damaged. Putting them on the roof gets them away from the ground. There’s really no one size fits all solution, you have to figure out what is best for your particular location and situation. Cost of the system will be around $4,000+/- all up and will provide power to run my house, my hangar, and charge a to-be-bought electric car. Breakeven without the car is a bit over three years, with the car it could be a bit over two years. Designed the system in about three hours using Chatgpt, it gave me part numbers, wire sizes, best inverters to use, breaker size, panel layout, the works. Building inspector was flabbergasted, said he’d never seen such a well thought out system.
Was the building inspector also a chatbot?
That last line from sounds like it’s Tr*mp talking.
Talking of the issue though: if they stand up you can hinge them down maybe and put some wood panels on them if a storm is coming, like you do with the windows.
Or make them wheeled and roll them in storage.
Not sure if any of that is practical and cost-effective though.
When it comes to surviving hurricanes I’d suggest no matter where you mount them the risks of damage if you leave them out unprotected are very high, and probably similarly damaging – a solar fence falling flat probably won’t be harmed by the fall as the panels are way tougher than you’d think. But the hard sharp heavy debris hit which could happen to any of them…
So if you want a solar install at all part of your hurricane prep I’d think aught to be doing something to ensure you have power on the other side. For a solar fence that is at ground level make it easy to simply remove and stack those panels in your garage/hallway or somewhere similarly protected. On the roof probably too difficult to do anything much if you didn’t design the whole setup with a way of protecting it in mind, as you don’t want to be on a roof trying to take your panels down in the pre storm but still high winds…
Well, there is one type of fence that can withstand a hurricane… When do you think we’ll welcome the new era of chain link solar?
My only gripe is that [Dave] appears to have put the panels close enough to each other that they’re in danger of shading each other at certain times and skewing the data.
Otherwise it’s great to see some solid data rather than the usual mix of either super optimistic marketing BS or anti-renewables FUD that permeates the internet.
So do reflectors help?