7 ms·

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

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 1y ago
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 1y ago
  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-vertical-solar-panels-shine-in-norway/ https://cleantechnica.com/2025/09/27/bifacial-rooftop-vertic...
  - water-data-dude 1y ago
    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 1y ago
    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 1y ago
      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 1y ago
        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 1y ago
  Instead of mounting on a roof, maybe this should be used in place of fences.
  - jtr1 1y ago
    One thing Jenny Chase (longtime solar analyst with Bloomberg) likes to point out is that in many places, solar panels are actually cheaper than fencing materials [1] 1. https://www.ted.com/talks/jenny_chase_solar_energy_is_even_cheaper_than_you_think/transcript https://www.ted.com/talks/jenny_chase_solar_energy_is_even_c...
    - Scoundreller 1y ago
      How they hold up to kid’s soccer balls tho?
      - collinmcnulty 1y ago
        When I bought my solar panels, they showed me their test video of launching balls at them to simulate hail. They said you're toast if it gets to baseball size but below that you should be fine.
    - HankStallone 1y ago
      Unfortunately, she doesn't say what kind of fence she's talking about. The kind of fancy privacy fence people put up between yards, maybe; but I'd be impressed if they're cheaper than livestock fence, which is the context some people are talking about in this thread. A typical cattle fence (woven wire, steel posts, barbed wire on top) will cost about $2500 per quarter-mile right now for the materials. I'm not sure what a quarter-mile of solar panels four feet high would cost, or whether they'd survive the occasional cow rubbing on them. Neat idea, though.
thijson 1y ago
Vertical also doesn't take up very much real estate.
- scotty79 1y ago
  if you put up just one row and don't mind the shadow
  - namibj 1y ago
    You mean like a privacy fence?
    - scotty79 1y ago
      Sort of, but if you use it as a fence you'd need to ensure nothing casts shadow on it.
      - namibj 1y ago
        It's more that you have to manage shading to happen in a way that the module's structure and your array-combining wiring/circuit effectively contain the shading impact to be closer to proportional to the overall shaded area than to causing more catastrophic loss (an individual solar cell in a module will be wired/biased as a blocking diode that's merely photoconductive from the limited light it receives unless bypass diodes are integrated into the module). E.g., usage of power optimizers, modules/panels with cell&bypass-diode arrangements that work to effectively target and mitigate the shading patterns you experience (e.g. a wall getting shaded when the sun sets below the horizon formed by neighbor's roofs), and such. Partial-shading-tolerance designed modern panels will quite happily tank partial shading, and as long as you keep the shading aligned in the design direction of the panel you will have within ~30% of the usual efficiency (i.e., still like 14% instead of the usual 20%) relative to the remaining irradiation that your panel is still receiving after the shading took it's chunk. Just take care to ensure the shading conditions for all panels that are passively combined into an array are sufficiently same, or at least behave in a way that the modules can bypass effectively to not loose an unshaded panel's yield due to one panel in the group having some shade on it.
blackoil 1y ago
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 1y ago
  Germany allows apartment tenants to hang panels on their balcony and feed 800W for their needs. https://www.canarymedia.com/articles/solar/how-germany-outfitted-half-a-million-balconies-with-solar-panels https://www.canarymedia.com/articles/solar/how-germany-outfi...
  - toomuchtodo 1y ago
    Utah also. https://diysolarforum.com/threads/plug-in-balcony-solar-becomes-legal-in-utah-but-power-company-has-concerns-with-devices-currently-available.111602/ https://diysolarforum.com/threads/plug-in-balcony-solar-beco...
    - Scoundreller 1y ago
      Assuming they can’t/won’t/shouldn’t back feed, that’s a lot easier to do in most of 240V single phase land. In US/Canada, you gotta pick the side of your building’s circuit that your continuous loads are usually on.
      - actionfromafar 1y ago
        I don't understand what's different...
      - toomuchtodo 1y ago
        We're only talking ~800W 120V in most cases, so phase balancing is immaterial in this use case (in the context of balcony solar). Edit: For larger installs (many vertical panels, >1kw), agree that balancing and a dedicated circuit is likely more optimal.
dinfinity 1y ago
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".
- cman1444 1y ago
  Just to be clear, this is only advantageous when compared to fixed solar panels, not solar tracking ones correct?
  - Scoundreller 1y ago
    Absolutely but tracking is expensive relative to just throwing more panels at the problem. But shading is also a factor. If you want to get unobstructed sun across the whole day, you need to be built on a nice curve of a hill? Or build just a straight line of panels?
  - throwup238 1y ago
    Depends on what you mean by advantageous. Solar tracking setups are very expensive relative to a fixed panel one. They can produce more power per square meter via higher utilization but cost so much it makes more sense to just buy more panels if you have the space.
    - cman1444 1y ago
      I meant advantageous in that the anti-duck-curve of these panels would only be superior compared to the duck curve of a fixed panel. But that it would be inferior compared to the (what I presume is) the very high peak of the regular-duck-curve of a traditional solar tracking panel, since the "tails" of the curve should be similar at sunrise/sunset. But I see now that solar tracking seems to have fallen out of favor due to the economics of how cheap panels are.
  - Loic 1y ago
    The economics changed, it is now cheaper to put more panels East/West than having tracking ones as the tracking hardware is expensive. The tracking panels have the advantage to be put vertically in case of heavy hail.
lawlessone 1y ago
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.
sandworm101 1y ago
Only at lower latitudes. In the high north, the better config is vertical but one-sided in a V pointing south. Ideally then, one panel is face-on during the long sunrise, the other during the long sunset. Compare to at the equator where one side of a two-sided panel is facing the sunset/rise. This opens the interesting prospect of hinged vertical pannels that could be adjusted for the season, opening up the V in winter and closing it in summer
- nick49488171 1y ago
  Bifacial panels are almost as cheap as single panels though, at least when I look at clearance panels. Does that affect which is better?
layoric 1y ago
Not having snow accumulate on the panels definitely will be contributing to that gain since a bunch is lost on more horizontal panels in those parts of the world due to a layer of snow sitting on top for quite some time after the event. One big trade off/risk is a large vertical panel essentially becomes a sail in high winds.
littlecranky67 1y ago
4. they can be setup in places where flat-mounted panels are not an option, like agriculturally used fields. Veritcal pannels allow livestock and/or food production on those areas, while preserving access for tractors and machinery. A vertical panel has infinite higher efficiency that a flat-mounted one, if a flat-mounted one couldn't be constructed due to floor requirements.
- dotancohen 1y ago
  Even a vertical panel will sweep shadows across the fields. Many vertical panels sweeping many shadows will probably affect many types of agriculture.
  - SideburnsOfDoom 1y ago
    > Many vertical panels sweeping many shadows will probably affect many types of agriculture yes, and sometimes it's a positive effect. source is e.g. https://theconversation.com/how-shading-crops-with-solar-panels-can-improve-farming-lower-food-costs-and-reduce-emissions-202094 https://theconversation.com/how-shading-crops-with-solar-pan...
  - jojobas 1y ago
    A lot of crops actually yield better in partial shade and are grown in open fields as shading is more expensive than the yield penalty.
  - namibj 1y ago
    Unless you're planting energy crops like corn or canola, that aspect tends to be still net-positive even if perhaps a bit of the solar yield has to pay off a minor reduction in crop yield. Notably though grazing pasture mostly doesn't complain and if mounted suitably (IIUC low enough density and high enough start above the ground), it can co-exist with effective nature preserves.
- ratelimitsteve 1y ago
  this is an instantiation of my favorite problem-solving maxim that I learned in spirit as a boy scout: "Doing something suboptimal is almost always better than not doing something optimal." When my scoutmaster said it it had a few more four letter words and smelled like cherry brandy, but it was still true.
masklinn 1y ago
I strongly recommend watching Dave’s entire video, it’s really extensive and interesting. Notably while the N/S bifacial have an amazing showing in sunny winter day with ground snow (as well a significantly higher resilience against snowfalls), the year round testing he did shows that the performance crater in spring, with half the performance of standard inclined panels, and none of the morning / evening advantages of E/W bifacials. In the end, the N/S verticals have a worse year round production than every other setup, and significantly worse than standard, but if you live in a location with a fair amount of winter snow and can swing (heh) it a tilting mount could be an interesting configuration for winter.
- nobrains 1y ago
  What if we do vertical bi-facial panels, mounted on a rotating circle that rotates to align the panels with the sun (north-south or east-east or in between) depending on the time of the year. Wouldn't that be the best of all worlds right now?
  - masklinn 1y ago
    On a theoretical basis yes but a tracking array gets a lot more expensive, and a lot less reliable. The rotating circle also takes a huge amount of ground space.
    - paduc 1y ago
      If you put the panels in a diagonal (NW - SE), and you rotate each panel on its vertical axis, the need for space would be limited to a series of circles the diameter of the panel width.
      - jmkd 1y ago
        No expert on the topic but surely a manually rotated system achieves the benefits of tracking without the overhead of installation and maintenance for an automatic system. As long as the panels are easily reverted to default position when no one can go and rotate them through the day (thinking domestic setup in the garden). Plenty of people have gardens and land that is tended to multiple times through the day anyway (for gardening, animals, workshop activity etc).
DanielHB 1y ago
> 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. I guess you also don't need to remove the snow from the panels?

Havoc 1y ago

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 1y ago
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-vertical-solar-panels-shine-in-norway/ https://cleantechnica.com/2025/09/27/bifacial-rooftop-vertic...
- water-data-dude 1y ago
  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 1y ago
  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 1y ago
    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 1y ago
      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 1y ago
Instead of mounting on a roof, maybe this should be used in place of fences.
- jtr1 1y ago
  One thing Jenny Chase (longtime solar analyst with Bloomberg) likes to point out is that in many places, solar panels are actually cheaper than fencing materials [1] 1. https://www.ted.com/talks/jenny_chase_solar_energy_is_even_cheaper_than_you_think/transcript https://www.ted.com/talks/jenny_chase_solar_energy_is_even_c...
  - Scoundreller 1y ago
    How they hold up to kid’s soccer balls tho?
    - collinmcnulty 1y ago
      When I bought my solar panels, they showed me their test video of launching balls at them to simulate hail. They said you're toast if it gets to baseball size but below that you should be fine.
  - HankStallone 1y ago
    Unfortunately, she doesn't say what kind of fence she's talking about. The kind of fancy privacy fence people put up between yards, maybe; but I'd be impressed if they're cheaper than livestock fence, which is the context some people are talking about in this thread. A typical cattle fence (woven wire, steel posts, barbed wire on top) will cost about $2500 per quarter-mile right now for the materials. I'm not sure what a quarter-mile of solar panels four feet high would cost, or whether they'd survive the occasional cow rubbing on them. Neat idea, though.

thijson 1y ago

Vertical also doesn't take up very much real estate.

scotty79 1y ago
if you put up just one row and don't mind the shadow
- namibj 1y ago
  You mean like a privacy fence?
  - scotty79 1y ago
    Sort of, but if you use it as a fence you'd need to ensure nothing casts shadow on it.
    - namibj 1y ago
      It's more that you have to manage shading to happen in a way that the module's structure and your array-combining wiring/circuit effectively contain the shading impact to be closer to proportional to the overall shaded area than to causing more catastrophic loss (an individual solar cell in a module will be wired/biased as a blocking diode that's merely photoconductive from the limited light it receives unless bypass diodes are integrated into the module). E.g., usage of power optimizers, modules/panels with cell&bypass-diode arrangements that work to effectively target and mitigate the shading patterns you experience (e.g. a wall getting shaded when the sun sets below the horizon formed by neighbor's roofs), and such. Partial-shading-tolerance designed modern panels will quite happily tank partial shading, and as long as you keep the shading aligned in the design direction of the panel you will have within ~30% of the usual efficiency (i.e., still like 14% instead of the usual 20%) relative to the remaining irradiation that your panel is still receiving after the shading took it's chunk. Just take care to ensure the shading conditions for all panels that are passively combined into an array are sufficiently same, or at least behave in a way that the modules can bypass effectively to not loose an unshaded panel's yield due to one panel in the group having some shade on it.

blackoil 1y ago

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 1y ago
Germany allows apartment tenants to hang panels on their balcony and feed 800W for their needs. https://www.canarymedia.com/articles/solar/how-germany-outfitted-half-a-million-balconies-with-solar-panels https://www.canarymedia.com/articles/solar/how-germany-outfi...
- toomuchtodo 1y ago
  Utah also. https://diysolarforum.com/threads/plug-in-balcony-solar-becomes-legal-in-utah-but-power-company-has-concerns-with-devices-currently-available.111602/ https://diysolarforum.com/threads/plug-in-balcony-solar-beco...
  - Scoundreller 1y ago
    Assuming they can’t/won’t/shouldn’t back feed, that’s a lot easier to do in most of 240V single phase land. In US/Canada, you gotta pick the side of your building’s circuit that your continuous loads are usually on.
    - actionfromafar 1y ago
      I don't understand what's different...
    - toomuchtodo 1y ago
      We're only talking ~800W 120V in most cases, so phase balancing is immaterial in this use case (in the context of balcony solar). Edit: For larger installs (many vertical panels, >1kw), agree that balancing and a dedicated circuit is likely more optimal.

dinfinity 1y ago

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".

cman1444 1y ago
Just to be clear, this is only advantageous when compared to fixed solar panels, not solar tracking ones correct?
- Scoundreller 1y ago
  Absolutely but tracking is expensive relative to just throwing more panels at the problem. But shading is also a factor. If you want to get unobstructed sun across the whole day, you need to be built on a nice curve of a hill? Or build just a straight line of panels?
- throwup238 1y ago
  Depends on what you mean by advantageous. Solar tracking setups are very expensive relative to a fixed panel one. They can produce more power per square meter via higher utilization but cost so much it makes more sense to just buy more panels if you have the space.
  - cman1444 1y ago
    I meant advantageous in that the anti-duck-curve of these panels would only be superior compared to the duck curve of a fixed panel. But that it would be inferior compared to the (what I presume is) the very high peak of the regular-duck-curve of a traditional solar tracking panel, since the "tails" of the curve should be similar at sunrise/sunset. But I see now that solar tracking seems to have fallen out of favor due to the economics of how cheap panels are.
- Loic 1y ago
  The economics changed, it is now cheaper to put more panels East/West than having tracking ones as the tracking hardware is expensive. The tracking panels have the advantage to be put vertically in case of heavy hail.

lawlessone 1y ago

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.

sandworm101 1y ago

Only at lower latitudes. In the high north, the better config is vertical but one-sided in a V pointing south. Ideally then, one panel is face-on during the long sunrise, the other during the long sunset. Compare to at the equator where one side of a two-sided panel is facing the sunset/rise. This opens the interesting prospect of hinged vertical pannels that could be adjusted for the season, opening up the V in winter and closing it in summer

nick49488171 1y ago
Bifacial panels are almost as cheap as single panels though, at least when I look at clearance panels. Does that affect which is better?

layoric 1y ago

Not having snow accumulate on the panels definitely will be contributing to that gain since a bunch is lost on more horizontal panels in those parts of the world due to a layer of snow sitting on top for quite some time after the event. One big trade off/risk is a large vertical panel essentially becomes a sail in high winds.

littlecranky67 1y ago

4. they can be setup in places where flat-mounted panels are not an option, like agriculturally used fields. Veritcal pannels allow livestock and/or food production on those areas, while preserving access for tractors and machinery. A vertical panel has infinite higher efficiency that a flat-mounted one, if a flat-mounted one couldn't be constructed due to floor requirements.

dotancohen 1y ago
Even a vertical panel will sweep shadows across the fields. Many vertical panels sweeping many shadows will probably affect many types of agriculture.
- SideburnsOfDoom 1y ago
  > Many vertical panels sweeping many shadows will probably affect many types of agriculture yes, and sometimes it's a positive effect. source is e.g. https://theconversation.com/how-shading-crops-with-solar-panels-can-improve-farming-lower-food-costs-and-reduce-emissions-202094 https://theconversation.com/how-shading-crops-with-solar-pan...
- jojobas 1y ago
  A lot of crops actually yield better in partial shade and are grown in open fields as shading is more expensive than the yield penalty.
- namibj 1y ago
  Unless you're planting energy crops like corn or canola, that aspect tends to be still net-positive even if perhaps a bit of the solar yield has to pay off a minor reduction in crop yield. Notably though grazing pasture mostly doesn't complain and if mounted suitably (IIUC low enough density and high enough start above the ground), it can co-exist with effective nature preserves.
ratelimitsteve 1y ago
this is an instantiation of my favorite problem-solving maxim that I learned in spirit as a boy scout: "Doing something suboptimal is almost always better than not doing something optimal." When my scoutmaster said it it had a few more four letter words and smelled like cherry brandy, but it was still true.

masklinn 1y ago

I strongly recommend watching Dave’s entire video, it’s really extensive and interesting. Notably while the N/S bifacial have an amazing showing in sunny winter day with ground snow (as well a significantly higher resilience against snowfalls), the year round testing he did shows that the performance crater in spring, with half the performance of standard inclined panels, and none of the morning / evening advantages of E/W bifacials. In the end, the N/S verticals have a worse year round production than every other setup, and significantly worse than standard, but if you live in a location with a fair amount of winter snow and can swing (heh) it a tilting mount could be an interesting configuration for winter.

nobrains 1y ago
What if we do vertical bi-facial panels, mounted on a rotating circle that rotates to align the panels with the sun (north-south or east-east or in between) depending on the time of the year. Wouldn't that be the best of all worlds right now?
- masklinn 1y ago
  On a theoretical basis yes but a tracking array gets a lot more expensive, and a lot less reliable. The rotating circle also takes a huge amount of ground space.
  - paduc 1y ago
    If you put the panels in a diagonal (NW - SE), and you rotate each panel on its vertical axis, the need for space would be limited to a series of circles the diameter of the panel width.
    - jmkd 1y ago
      No expert on the topic but surely a manually rotated system achieves the benefits of tracking without the overhead of installation and maintenance for an automatic system. As long as the panels are easily reverted to default position when no one can go and rotate them through the day (thinking domestic setup in the garden). Plenty of people have gardens and land that is tended to multiple times through the day anyway (for gardening, animals, workshop activity etc).

DanielHB 1y ago

> 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. I guess you also don't need to remove the snow from the panels?