[HN Gopher] Vertical Solar Panels Are Out Standing
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       Vertical Solar Panels Are Out Standing
        
       Author : lxm
       Score  : 98 points
       Date   : 2025-09-29 14:22 UTC (8 hours ago)
        
 (HTM) web link (hackaday.com)
 (TXT) w3m dump (hackaday.com)
        
       | dylan604 wrote:
       | Am I reading this correctly? Vertically they produce 77% compared
       | to 90% of the tilted panels? In what graph is the lower number
       | better?
       | 
       | Also: "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."
       | 
       | Isn't that the same thing? Is one of the sides specifically meant
       | to face the sun? Maybe I'm just not as knowledgeable about solar
       | panels, but what sunlight is being harnessed by the backside of
       | the sun facing panel? Are they catching reflected light,
       | otherwise, they are directly in shadow.
        
         | jszymborski wrote:
         | > Isn't that the same thing?
         | 
         | I had the same reaction. I noticed the top comment reading
         | "some of us live in the southern hemisphere" so maybe this was
         | a quick edit and not thought through?
         | 
         | Unless one of the sides of the panel is meant to face north,
         | but that doesn't sound likely
        
         | detaro wrote:
         | Bifacial panels usually have one side that's a bit more more
         | efficient than the other. The backside can catch reflections,
         | sky light on overcast days, ...
         | 
         | But it's usually more common to orient them east-west, so they
         | have peaks in the mornings and in the afternoon/evening, which
         | combines well with other solar panels that are mounted south-
         | facing, or might even just match your electricity consumption
         | pattern better.
        
         | msandford wrote:
         | If you look at the far right hand bar the B-N/S says 131% which
         | is the highest bar on the chart. So it's producing more than
         | the standard tilted slightly south orientation from what I
         | gather. The legend is a bit hard to read for sure.
        
         | petters wrote:
         | > Isn't that the same thing?
         | 
         | Yes, it's a joke.
        
           | dylan604 wrote:
           | If bifacial panels are made so each side is the same making
           | orientation not an issue, then sure, hahahaha (not really.
           | it's a lame joke). If there is a back side, then you
           | absolutely need to reverse the orientation depending on
           | hemisphere. It would be better stated that they need to be
           | pointed towards the equator. If these are literally
           | reversible, it seems like wasted money to me as one side will
           | never produce as much as the reverse does.
        
         | Workaccount2 wrote:
         | The hemisphere talk is a joke, the situation being shown off
         | here is one where there is snow in the ground, which greatly
         | increases the amount of sunlight hitting the backside panel.
         | 
         | This is also in January, when the sun in Ohio is very low in
         | the southern sky. So north/south oriented panels are much more
         | ideal.
        
         | Linosaurus wrote:
         | > Vertically they produce 77% compared to 90% of the tilted
         | panels? In what graph is the lower number better?
         | 
         | 77% of the 'normal orientation' per year, but the graph and
         | 131% value is for a day in winter (January 15 this year). At
         | least that's my read.
        
           | JumpCrisscross wrote:
           | I also believe vertical panels produce more than flat panels
           | in the mornings and evenings, thereby giving them anti-duck
           | curve properties.
        
           | dylan604 wrote:
           | So one day of the year is producing 131% yet still only
           | averages 77% for the year? Yeah, that sounds like a good
           | trade off. /s
           | 
           | I'm still trying to decide if the entire post is trolling or
           | not. Nothing about it sounds sane to me.
        
             | Xylakant wrote:
             | So your problem is that during summer, average solar
             | production is much higher than in winter in the first
             | place. So to ensure that you have sufficient energy in
             | winter, you can either overprovision heavily for summer use
             | (lots of flat panels facing south) or you can sacrifice
             | summer efficiency to gain winter efficiency - vertical
             | panels do that.
        
             | fckgw wrote:
             | It's not just about production, it's also about reducing
             | maintenance costs (don't collect snow, less dust build up
             | on panels) and land usage. If you can take that 77%
             | average, but maybe stick a couple more panels on land to
             | reach your energy goals in an overall smaller footprint
             | with less maintenance work, then maybe it's a good solution
             | to specific problems.
        
             | adgjlsfhk1 wrote:
             | If you had a solar panel that produced half as much power
             | as regular, but produced power at night that would be a
             | massive win. This is a less extreme equivalent. It produces
             | less power than a normal solar pannel, but it produces
             | power at an important time (when regular solar panels don't
             | produce much power).
        
         | dessimus wrote:
         | The graph confused me for a moment, but then realized the graph
         | is showing the winter with SNOW on the ground, not the general
         | case. So in the winter the vertical panels produce more power
         | than tilted panels in very specific conditions and depending on
         | how often that occurs, it may make up for the loss in
         | efficiency during other times of the year. I'm guessing the
         | vertical panels gain some advantage of the sun reflecting off
         | the snow and into the vertical panel that the tilted panels do
         | not, especially when the sun is at low angles to the horizon.
        
       | xnx wrote:
       | It's such an interesting optimization problem. Maximizing annual
       | production isn't the only goal. It's also about: never running
       | out of power, having surplus power when useful, minimizing
       | installation cost, minimizing maintenance cost, guarding against
       | dust and hail, minimizing use of land, etc.
       | 
       | Approaches range from straight vertical to flat on the ground:
       | https://erthos.com/earth-mount-solar/
        
         | goda90 wrote:
         | Earth mounting reminds me of when I used to daydream about
         | autonomous, mobile, solar panel factories to cover huge swathes
         | of sandy desert with solar panels. I doubt the mobile factory
         | thing would ever make sense, but autonomous installation would
         | be really cool.
        
           | toss1 wrote:
           | Combine it with the desert reclamation efforts finding
           | success pushing back the Sahel, and it could be amazing
        
         | colechristensen wrote:
         | The cost is now at the point where we don't care so much about
         | actually using every watt and when we do need more watts at a
         | particular time we add more in "inefficient" configurations to
         | supply it.
         | 
         | Whole industries are going to pop up to take advantage of the
         | intermittent very cheap electricity. Also there will be a
         | competitive balance between the cost of storage and the "cost"
         | of non-optimally aligned solar panels.
        
       | simpsond wrote:
       | Utility scale fields tend to have single axis trackers which can
       | optimize output. They are expensive though. I wonder if a manual
       | rack that could lock at 30 or 90 could work and be cost
       | effective.
        
       | marcodiego wrote:
       | Come on: "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."
       | 
       | That is not the kind of thing I come here for.
        
         | YcYc10 wrote:
         | I'm assuming that's a joke, but who knows.
        
           | magicalhippo wrote:
           | As Dave has shown in previous videos, bifacials are not
           | symmetrical, and the backside produces less power under same
           | conditions. So N-S would be different from S-N orientation.
        
       | wzdd wrote:
       | In their field?
        
       | gorfian_robot wrote:
       | I read somewhere (maybe in Dave's youtube comments) that the
       | price of fencing is high enough that some folks have used
       | bifacial vertical solar panels as a fence.
        
       | floatrock wrote:
       | Article doesn't give a whole lot of context, but there's two key
       | innovations here:
       | 
       | 1. Bi-facial solar panels: can take in sunlight from either end
       | 
       | 2. Mounting bi-facials vertically so they can take in sunlight
       | from both directions.
       | 
       | I've been hearing experiments about these for a few years now.
       | There's three main benefits to the vertical arrangement that
       | could, given certain situations, make it more economically
       | valuable:
       | 
       | 1. In places with high-albedo snowy winters, this arrangement can
       | boost winter production, which if you have snow, tends to be the
       | energy-heavy time of year.
       | 
       | 2. Keeps panels cooler. Panels lose efficiency when they get hot,
       | and by having them vertical, they can run cooler. Losses in less
       | direct sunlight are somewhat offset by efficiency gains from
       | cooler operations.
       | 
       | 3. More power during shoulder periods (anti-duck-curve).
       | Especially in places like California that have high solar
       | penetration, prices for excess energy are minimal during peak
       | solar activity. Vertical arrangements give more power in the
       | morning and evening, which is when traditional fields are just
       | ramping up or ramping down. Thus, even if you're making less
       | power overall, you can be making _more valuable_ power by having
       | more production during these ramp-up /ramp-down periods.
       | 
       | Unclear how much of an effect these counter-acting forces
       | actually add, but I understand solar developers are looking into
       | these arrangements.
        
         | Havoc wrote:
         | The one gotcha is that roof mounting for vertical is a bit of a
         | headache & the structural support is often precisely the wrong
         | way round.
        
           | bryanlarsen wrote:
           | This is an interesting application; it sounds like they've
           | worked through a bunch of those issues:
           | https://cleantechnica.com/2025/09/27/bifacial-rooftop-
           | vertic...
        
             | water-data-dude wrote:
             | Interesting that they list wind as one of the places where
             | vertical panels have the advantage - my intuition would
             | have been the other way around, with angled panels doing
             | better in windy conditions. Wind uplift isn't something I'd
             | have even thought about.
        
             | Havoc wrote:
             | I meant more on a classic home with an A-frame like roof.
             | 
             | Don't think it's a coincidence that the demo vid they're
             | showing off is a flat factory roof
        
               | estimator7292 wrote:
               | Yeah, I mean the peak of such a roof is the only
               | practical place for it. I'd say this style of mounting is
               | simply not appropriate for all types of roofs, and that's
               | not exactly a _bad_ thing, just geometry
        
               | jasonwatkinspdx wrote:
               | Yeah, and the mounting would need to be robust enough to
               | withstand the panels acting like a sail in storm winds.
               | 
               | I think it'd be interesting to look at how these might be
               | colocated with crops.
        
           | giantg2 wrote:
           | Instead of mounting on a roof, maybe this should be used in
           | place of fences.
        
         | thijson wrote:
         | Vertical also doesn't take up very much real estate.
        
           | scotty79 wrote:
           | if you put up just one row and don't mind the shadow
        
         | blackoil wrote:
         | Can they be used in apartment. We don't have roof space but can
         | hang them vertically from balcony. Bi-facial won't work but
         | what about mono-facial?
        
           | aitchnyu wrote:
           | Germany allows apartment tenants to hang panels on their
           | balcony and feed 800W for their needs.
           | 
           | https://www.canarymedia.com/articles/solar/how-germany-
           | outfi...
        
           | te0006 wrote:
           | If you have a south (or SE or SW) facing wall without much
           | shadowing from nearby buildings or trees, vertikal mounting
           | does work OK. Do not expect to reach the panel's nominal Wp
           | rating though, output will peak at 50-70% of that. But panels
           | are cheap - if there's enough room, just overprovision
           | twofold. Just take care to buy an inverter that is OK with
           | such a bigger configuration. And vertically mounted panels
           | will generate more power off-season than tilted ones.
        
         | dinfinity wrote:
         | The anti-duck-curve is actually really, really pronounced for
         | east-west mounted bifacial panels.
         | 
         | The panels still don't generate any electricity at night of
         | course, but other than that the output is an almost perfect
         | inverse of the conventional equator-facing angled mounted panel
         | output.
         | 
         | Just search for "bifacial solar panels graph".
        
         | lawlessone wrote:
         | Living north western Europe, a good chunk of the year the sun
         | is basically only coming from the side most of the day
         | (nightmare for driving btw).
         | 
         | This might work a lot better.
        
       | jws wrote:
       | At 45degN latitude, I keep mine nearly vertical year round. I
       | used to adjust them 4 times a year for more optimal production.
       | There are issues beyond angle of incidence. Being nearly vertical
       | keeps the snow off in the winter. In the summer it reduces the
       | cleaning required (it's a sea bird rookery, so that's kind of a
       | lot). Beyond that, the telemetry needs are constant year round so
       | if the panels can cover the needs in the winter, then summer is
       | no problem.
       | 
       | My current strategy for small installations when you have an
       | equator facing wall or fence is slap the panels on it and be done
       | with it.
        
       | hunterpayne wrote:
       | This setup almost certainly took more carbon to make than it will
       | ever replace. This is usually true anywhere it snows regularly.
       | There are a couple of exceptions, but unless you are above 7000ft
       | of elevation you are just making the problem worse. This guy
       | should donate this setup to someone in Mexico where it would make
       | sense.
        
         | AnotherGoodName wrote:
         | You need to back that up with genuine analysis and proven
         | studies.
         | 
         | The reason i say this is that in some parts of the world
         | capitalist things like building renewables to make or save
         | money is politicised as a left or right wing issue with people
         | arbitrarily for or against purely on that bucketing.
         | 
         | The politicisation is stupid and doesn't even align well to any
         | traditional left/right political divide other than 'at one
         | point in history they fell on one side or the other of the
         | issue' so now they are stuck there. It's interesting with the
         | perspective of someone who's experienced a different countries
         | right/left wing politics which have completely different views
         | on various issues. As in there's often no reason for such
         | things to be in either side honestly. In fact for certain
         | things that never got politicised in the USA such as battery
         | storage the red states are leading the world in grid connected
         | battery installation rates since it's so profitable and the
         | topic has avoided being bucketed into a left/right category all
         | the while blocking offshore wind farm installation which has
         | been bucketed as such.
         | 
         | Anyway due to this politicisation you cannot just post 'this
         | renewable initiative doesn't work' without honest analysis to
         | back it up. This would need to include the massive drop in
         | solar power and battery prices that have occurred recently.
        
         | wolfram74 wrote:
         | I'm juggling a baby approaching lunch time at the moment, so I
         | can't go into too much depth on this paper[0] I found 40
         | seconds ago, but the conclusion seems to think that solar panel
         | EROIE in siwtzerland is somewhere between 7 and 10, which as a
         | proxy for carbon intensity, /probably/ means it will actually
         | result in net carbon reduction.
         | 
         | [0]https://www.sciencedirect.com/science/article/pii/S030142151
         | ...
        
           | Implicated wrote:
           | Congrats!
        
         | mixmastamyk wrote:
         | Very short term thinking. How will it improve if no one tries?
         | 
         | Reminds me of the critics of digital photography circa the year
         | 2000.
        
       | malchow wrote:
       | In addition to bi-facials starting to work quite well, HNers may
       | be interested in a rising class of ultra-low-mass material that
       | has come out of work at Stanford and Intel in transition-metal
       | dichalcogenides (TMDs) (e.g. for MoS2, WS2, WSe2, etc.).
       | 
       | It turns out these enable a very high specific-power PV cell that
       | adds another even more attractive production curve behind what is
       | happening in vertical bi-facials. See e.g.:
       | 
       | https://ee.stanford.edu/frederick-nitta-koosha-nassiri-nazif...
       | 
       | https://www.arinna.xyz/
        
       | jillesvangurp wrote:
       | A comment that I heard recently is that in some places using
       | solar panels is literally cheaper than using wood panels for
       | fences.
       | 
       | I'm not sure how true that is of course but it does make you
       | think a bit. The optimal place where to put solar panels
       | increasingly is becoming "wherever you can afford to". If
       | vertical space is what you have, why not use it?
       | 
       | People in apartments don't have access to roofs. But they might
       | have balconies. Balcony railings can fit a few solar panels
       | usually.
       | 
       | You can buy solar panels for use on balconies in the supermarket
       | in Germany. They only generate a few hundred watt. But that can
       | add up to close to something like a kwh per day if you get a lot
       | of sun on your balcony. At 40 cents per kwh. That's 12 or so
       | euros per month. I pay about 70 per month currently. And I can
       | get a couple of balcony panels for something like 200-300 euros.
       | And I might get some money back on those even. The idea with
       | balcony solar is that it might offset part of what your fridge
       | uses. You simply plug it into a wall socket and your fridge takes
       | that power instead of from the grid. All safe and approved
       | equipment, the inverter cuts the power if there is no grid power.
       | 
       | I haven't done this (my balcony faces east and only gets a few
       | hours of sun in the early morning). But it's easy to see how this
       | could work.
        
         | wiredfool wrote:
         | Quick look near here -- wood panels are ~50-99eur for .9->1.8m
         | x 1.8m fence panels. I've priced out 550W solar panels (which
         | should be about 1x2M) for about 100PS. (Both retail, but
         | different countries (ire/uk))
         | 
         | So, not price parity but also only about a factor of 2 or so.
         | On the other hand, Ali Express panels are about half that UK
         | price at a 10 panel quantity, with unknown shipping.
         | 
         | I'm kind of eyeing the concrete block wall in the back garden
         | currently covered by a hedge.
        
         | childintime wrote:
         | Sadly in Germany you mostly miss out on one big advantage one
         | often gets in sunny countries: power during outages.
         | 
         | That said, WW3 terrorism acts may change that. It could be wise
         | to have at least some backup.
        
           | somat wrote:
           | Almost no private solar installations give power during
           | outage, for the most part they use something called a grid
           | tied inverter. This uses the power grid to shape the waveform
           | and costs about a tenth of what a self shaping inverter
           | costs. the unexpected downside, no grid, no power.
           | 
           | I have yet to find conclusive evidence if it is possible to
           | use a small full inverter to drive grid tied inverters, that
           | is, have the grid off capability of a full inverter with the
           | cheap cost of a grid tied inverter. It sounds reasonable, but
           | I don't see anyone doing it.
        
             | giantg2 wrote:
             | You mean something like feeding a grid fed inverter an
             | artificially generated wave form from a Raspberry Pi and
             | some relays or something?
        
               | jvanderbot wrote:
               | I don't see why you can't flip a giant switch to go from
               | grid to home power. It's not automatic, but this tech is
               | well established for gas generator cutover in factories
               | and remote homes.
        
       | balderdash wrote:
       | How do vertical panels handle wind loads?
        
         | otherme123 wrote:
         | Two axis panels put themselves vertical on high winds, but
         | facing perpendicular to the wind direction. So it depends on
         | the wind direction.
        
       | scotty79 wrote:
       | I wonder why 30 deg was chosen. If you want to maximize energy
       | production in the winter they should be installed more vertically
       | so that for most of the winter the angle between the sun rays and
       | the panel is around 90 deg.
        
       | lacoolj wrote:
       | Is the title (here and on the article) supposed to say
       | "outstanding" as in "amazing! wonderful!" or is it deliberately
       | "out standing" as in ... standing...out...actually, I don't even
       | know if this is a valid phrase.
        
         | k2enemy wrote:
         | I am excited to be here while you experience your first pun!
        
           | lacoolj wrote:
           | Still need the explanation of what pun I'm missing, but
           | looking forward to seeing what you come up with :)
        
         | NortySpock wrote:
         | That's the joke, both are valid uses of the phrase and sound
         | alike.
         | 
         | "My scarecrow is the best in the business! He's out standing
         | (outstanding) in his field!" (i.e. a field in a farm, or in his
         | area of expertise)
        
       | vzaliva wrote:
       | bifacial panels indeed produce more electricity. but does it
       | justify the cost increase? simply speaking if bifacial panels
       | cost 2x, do they produce anything close to 2x electricity?
        
         | mixmastamyk wrote:
         | Looked like a lowest 6% boost in the winter, but more in the
         | summer. Likely makes sense as panel prices decrease.
        
         | bryanlarsen wrote:
         | The rule of thumb is that bifacial increases production by 35%
         | for a 10% cost increase. YMMV.
        
       | fortranfiend wrote:
       | They're out standing in the field. ...I'll let myself out.
        
       | giantg2 wrote:
       | Why not mount the double sided vertical panels edge towards the
       | sun with a mirror panel on each side? Add some passive cooling
       | channels between the panels, or even boost it with a small fan. I
       | would think that might result in even better gains instead of
       | having one side wirh full sun and the other eith indirect sun.
        
         | corysama wrote:
         | The same source (Dave) has a video from a year ago on vertical
         | panels with horizontal panels.
         | https://www.youtube.com/watch?v=xD1MT-ek05w
        
         | turtlebits wrote:
         | Solar panels are cheap. A single mirror that size likely will
         | cost more than the panel itself.
        
       | jiehong wrote:
       | They also better resist bad weather, like hail
        
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       (page generated 2025-09-29 23:00 UTC)