Vertical Solar Panels Are Out Standing | Hacker News Reader

Vertical Solar Panels Are Out Standing

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200 pointslxm170 comments

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.

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.

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...

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.

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

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

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.

Instead of mounting on a roof, maybe this should be used in place of fences.

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_c...

How they hold up to kid’s soccer balls tho?

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.

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.

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

if you put up just one row and don't mind the shadow

You mean like a privacy fence?

Sort of, but if you use it as a fence you'd need to ensure nothing casts shadow on it.

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.

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?

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...

Utah also.

https://diysolarforum.com/threads/plug-in-balcony-solar-beco...

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.

I don't understand what's different...

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.

I mean, if you can't backfeed, you might have stuff "on" in your home, but your solar might not be on that side so it's not doing you any good.

What a bizarre situation. So if you have extra balcony space, you are not allowed to generate more than 800W for your own use?

Perhaps it is an arbitrary limit picked out of concern for weight and / or live energy in a place normally meant as living quarters. Too much of either on a balcony would be a hazard, especially if everyone with a balcony was doing it simultaneously in buildings not really built with either in mind.

800w sounds low to me, especially on 120v in the US, but the rules may have been in place for older less efficient / bulkier panels in mind.

Mind you higher powers just need a licensed electrician to sign off and usually also have them permanently wire it in as those setups won't need an AC side plug so the costs of essentially a generator hookup over a fixed tie-in isn't worth it, and they require notifying the local grid. Might be that beyond 10kWp the grid can tell you sorry-capacity-not-ready (but the grid will have to fix that soon, there are rules) but yeah.

This is complicated legalese. "For your own use" doesn't technical exist, you are outputting your solar production into the main grid - and this is capped at 800W for grid (and house installation) safety and stability issues. You need a meter that can run backwards, but you have the right to demand from your electricity provider that they install one.

Bypassing the grid and using your own storage infrastructure is AFAIK not allowed in Germany (there are heavy taxes on electricity, that you would be omitting - similar as to how you technically are not allowed to make your own Schnaps at home due to taxing).

Last I read them, electricity tax was only applicable for sale and certain situations that involve transferring power across parcel/plot boundaries. An entity is allowed to generate it's own local solar power for own local consumption, and for that it's perfectly fine to rent/lease the equipment/panels but you can't just tax-free buy electricity itself outside some limited situations that are to allow e.g. an apartment tower to use solar panels as cladding to then sell the power to the tenants instead of forcing every tenant to lease their own electrically independent section of the facade.

You need me, an electrician, for bigger installation. 800W can be done by everyone and doesn’t require registration to grid operator and tests. Some people don’t mind having illegal 1600-2000W installations, never heard, that someone got fined for that. Generated energy (if not consumed) is not paid for anyway.

I think it's the plug-in part that is limiting the power. Most of these sets you just plug in to a existing outlet, not wired into the electricity panel. Feeding in 800 watt directly into the circuit allows you to draw more than the rated 16A 230 volt from that circuit without tripping the breaker. The ~20A you can manage this way is probably within safety margins of most installations.

Germany is a litigious country, with most of the things insured.

If people started plugging a 2kW grid tied inverter in a normal power socket - as is the case for balkonkraftwerk - houses would start catching on fire.

Nobody wants that. Yes, regulations are necessary for a safe and civil life.

You're not allowed to burn down "your" apartment building, because you didn't understand that its wiring was not designed for the extra load, or that overloaded wires get very hot.

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.

How well does a biphasic panel work mounted vertically on a light coloured wall at least a meter+ away (depending on panel size) ?

Just clad the wall between the windows (if any) in panels? Eases the wind loading that way as wind can't really get behind them anymore.

Think of them as (glass) fence panels with a convenient mounting frame. Just respect their dislike for partial shading from objects that are "near" (cast a hard shadow with wel defined borders relative to the cell/grid size on the panel), and it'll be fine. If they are arranged to have substantially different sun intensity and/or timing, run them through separate MPPTs or use "power optimizers" that do the same effort but without requiring more wires back to central than the simple "one single string of panels" has.

Due to recent issues out there: calculate worst winter peak voltage and make sure there's a healthy margin to the peak allowed safe/no-damage input voltage to the MPPT/charge-controller/inverter.

Panels eat less of their own current at any given operating voltage, the colder they are. And winter mornings after soaking in night cold are worst case conditions for that as they had no time to heat up yet for the first minutes past sunrise.

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".

Just to be clear, this is only advantageous when compared to fixed solar panels, not solar tracking ones correct?

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?

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.

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.

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.

My next array is likely to be east-west vertical bifacials, as I need only a small amount of additional capacity in the summer, but could still do more in the winter.

We currently have:

- summer optimised array: almost flat, 15 degree, optimised for maximum power on sunny summer days, mostly runs our cooling

- winter/morning array. Points SSE, 65 degree incline. Gets great energy in the mornings, and on winter mornings. Performs surprisingly well in overcast conditions. Generates about the same power in midwinter and midsummer.

- winter/afternoon array. Same as the above, but SSW.

18kW total faceplate capacity, in reality we peak at around 5kW, but have that for about six hours of the day for 9 months of the year. Also means I can run three arrays on two MPPTs as the two tilted arrays are basically mutually exclusive as to when they make power.

The other reason for leaning towards vertical panels is cleaning. The flat panels accumulate a crust of crap (pollen, soot, dust) that cements on there fast, and requires vigorous scrubbing to remove. Kills 20% of the capacity unless I get up there with a broom every six weeks. The 65 degree ones I have not had to clean once, as stuff just slides off them.

That, and a pallet of bifacials is now cheaper than a pallet of monofacials.

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.

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

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

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.

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.

Even a vertical panel will sweep shadows across the fields. Many vertical panels sweeping many shadows will probably affect many types of agriculture.

> 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-pan...

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.

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.

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.

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.

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?

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.

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.

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).

> the need for space would be limited to a series of circles the diameter of the panel width.

Now your panels start shading one another.

Maybe I wasn't clear, but in the precise NS and WE configurations, there should be no shading.

As soon as you add moving parts to your setup costs and maintenance explode. It's usually better to just buy more panels instead.

Depending on where you live a system that allows to manually change the tilt of your pannels once per month could be nice. You get a free 5-15% boost, where I am in Europe the optimal yearly tilt is ~40 degrees, in peak winter the optimal tilt of ~70 degrees would shed snow much more easily.

You're right on motorized trackers though, way too complex and expensive to make sense for most people

> Depending on where you live a system that allows to manually change the tilt of your pannels once per month could be nice. You get a free 5-15% boost, where I am in Europe the optimal yearly tilt is ~40 degrees, in peak winter the optimal tilt of ~70 degrees would shed snow much more easily.

Yup, that's what I was referring to as a tilting mount in the original comment, a pivot and tracks to tilt the panels up/down to set them at whatever's optimal for your latitude and time period, or completely vertical if you're in a snow-heavy region.

The necessary engineering might not be worth it anyway, given current panel prices, unless space is a bit of a premium.

Moving parts? We're talking about something like a pipe that's a hotdog down hallway slip fit onto another pipe here. With zero maintenance that will still have a service life that exceeds several generations of panel.

Plus at least one motor plus sun tracking controller. All of that has to operate 24/7, all year.

Depending on your local climate, that has to be sun and rain proof. (Most Nema 7 "3D printer" motors are not waterproof... Ask me now I know )

Nothing a quick hack job can't solve for you, but if you want to sell it (and make sure your customers will be satisfied for decades) it quickly adds up in price.

You don't need a motor. You need a recurring calendar reminder to send someone out there to spin them all 2x per year at whatever day you determine to be the ideal crossover point where you want to switch between NS and EW.

The panels can be stayed in their correct positions by a trash tire or whatever buried in the ground with two chains poking out to clip to the panel corner.

None of this is rocket science. This is all stuff that has been proven out over the past 200yr of fence and gate construction.

Similar could be used for changing between tilted and vertical though you'd need more material.

Panels have warranties of 25 years.

A pipe on a pipe will last close to 100 if you don't screw up the details...

vertical panels also kinda work as fences and aren't that much more expensive (actually might be cheaper...)

This. I am seeing this more in Austria and makes sense since a solar panel is really one of the most mass produced fence panel size things in the world. By choosing them you are also guaranteed replacement panels in the same dimensions compared to buying some random fence panel

Over the long term, there might be less wear and maintenance on either configuration. I'm guessing the vertical panels wins there.

> 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?

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.

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 100£. (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.

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.

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.

You mean something like feeding a grid fed inverter an artificially generated wave form from a Raspberry Pi and some relays or something?

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.

The hardest part of that is regulatory compliance on whatever interlock you have installed that prevents you from connecting mains to your backup.

The most common solution to that is a switch that goes through fully disconnected in the middle, and I've even seen a sliding metal plate used that interferes with at least one or both circuit breakers.

You need a home backup battery with a transfer switch, specifically one that accepts solar input. There are a bunch of off-the-shelf solutions out there.

Or you unplug your fridge from the wall and plug it into your inverter, with or without battery backup. Or you just leave it plugged into your APC UPS. I think cheaper ones than this US$60 2000W inverter exist: https://www.temu.com/ar/-2000w-inversor-de--con-pantalla-dig...

In the US they cost a lot more, but they still exist; there's a 750-watt unit at Horror Fright for US$70: https://archive.fo/1pzdK

I thought the generators phase differently with the movement of the engine vs the type of inverter you nened for use with batteries. I do agree it should be trivial.

You can, you need something to form frequency if it isn't coming from the grid and you very much need to synchronize when grid frequency comes back or your equipment will generate expensive smoke and noise.

> and costs about a tenth of what a self shaping inverter costs

I'm using a Fronius GEN24 Plus (10 kW) which can be used off-line/off-grid (called 'Full Backup', to use it you need some extra switching gear between the inverter and the utility hookup, which gear that is differs from country to country) and provides single-phase power in its default configuration (they call it 'PV power', basically a 3 kW single-phase connection which comes alive when the utility hookup goes down). While this inverter was slightly more expensive than the Chinese alternatives the difference was more in the range of 30%, not '10 times'.

Are there any systems offered that don’t have all the extra switch gear but just provides a socket you can plug something into? I figure people would be happy plug their fridge/freezer in manually to tun during the day and charge some stuff.

Or is that what you’re suggesting with the Chinese inverters?

https://www.myenergi.com/product/libbi-battery-storage/

The extra switching gear is needed for a utility hookup to ensure the inverter does not feed power into the utility hookup during a power-out. If the inverter is only to be used in island mode - without a utility hookup - such switching gear is not needed. You need to configure the inverter for island mode and you'll want to connect battery storage - this is a hybrid inverter which can be connected to one or more high-voltage (150V-510V) batteries - to power the system when the sun is down/low/obscured.

There are Chinese inverters which support island mode as well, my reason for choosing a European manufacturer is not related to this type of functionality. He who controls a large fleet of inverters can control the grid - and bring it down. I prefer to keep sole control over what my inverter does and do not allow it access to the internet, keeping it on a separate wired network (wireless access to the inverter is disabled) which is only accessible by a dual-hosted container on the server-under-the-stairs. It is through this container that I control the inverter and extract data for power management purposes - turn on heavy loads when the sun is doing its thing and/or imported electricity prices are at the lowest rates for the day. While I could (and would) do the same with a Chinese inverter I'm not convinced that would be enough to keep third parties from accessing the device though either some embedded 2/3/4G, LoRa or similar device.

I installed the panels on a barn I built in 2019 and installed the inverter in 2022 - long before my suspicions about the potential for such covert control channels were 'proven' [1] so my initial caution turned out to be justified.

[1] https://www.reuters.com/sustainability/climate-energy/ghost-...

I seem to recall almost two years ago when I was getting info on a possible solar install, we had the options of LG batteries or Powerwall, and one of the specific points of difference that the more expensive (and larger capacity) Powerwall battery install provided was stated to be power when the grid was down.

I can't speak to the accuracy of that, as I was speaking to a salesperson and I didn't go forward with the project so don't have any personal experience to add.

Please don’t spread misinformation. Every current Chinese inverter (Sungrow, Goodwe, you name it) can provide emergency power with or without installed battery. My all PV installations (10-20 kWp panels with 10-30 kWh batteries) provide emergency power for whole house. Battery has lower power than the grid connection, but clients agree to don’t charge their EVs during blackout. Starting cost 10000€ for 10 kWp panels and 10 kWh battery if installation is easy on single flat roof.

I have a rebranded kstar inverter which has a "backup" output and I had the electrician wire that output to 6 sockets around the house for fridge, well water pump, and internet connectivity. When the grid is on, the backup is fed by the grid. When the grid goes off, the panels deactivate and the backup is instantly (like a UPS) powered from the 5kWh battery. I can then manually switch off the grid connection to the inverter and re-activate the panels. It should be enough for backup loads more-or-less continuously although I should buy a better fridge and a winter storm might need us to reduce water consumption and disconnect internet.

Biggest disadvantage is that we don't have central heating during powercut - would require more invasive rewiring and more power than I care to draw from inverter with single battery. But gathering around wood stove and telling stories by candlelight is nice, eh?

It's just a matter of buying the right equipment. If you buy the wrong inverter, it just switches off when the grid goes out. You need some device that detects that and can disconnect from the grid (to prevent power going out to the grid) and then power the house. This is called islanding. Not all inverters support this. The ones that don't will switch off when the grid goes out. In addition to that, you might need a physical switch or transferring device that takes care of making sure no power leaks to the grid in case of an outage. Setups without this require inverters with anti-islanding that will switch off if the grid power drops.

Outages are rare enough here in Germany that few people go the extra effort and cost to install the necessary equipment. But with the right equipment (which is available if you go look for it), you can definitely get this installed. In places like Australia, outages are more common and it's generally not that costly to upgrade your setup to support proper islanding and it's more common for people to design their systems for this.

Of course people if feel compelled to prepare for WW III that might be a good motivation. On the other hand, we'll have bigger issues if it comes to that.

Alternatively, you can get a plug-in battery with solar input and AC outlet for pretty cheap. In normal times, the battery is only connected to an AC socket, and tries to balance out my daily usage (includes a power usage monitoring device in the breaker box). If/when the fan is hit with brown stuff, I can plug a few of my solar panels into the battery directly (they are now wired to my basic inverter without island mode), and then I still have some backup power.

It is not a solution for everyone, but redoing all my electricity hook-up, getting a whole-house battery and a three phase backup option would easily cost 20k. And it would cost a tonne of space, cause all this battery and inverter stuff needs to be close to the main connection (where I don't have space). The solution I chose was only 1200 for a 2kWh battery with built in inverter for 4 panels. And the battery is actually portable, I could technically use it for camping. Output is limited to 1200W AC from battery, or 2000W AC when there is enough solar input. To me spending 1200 Euro to have some electricity in case of WW III (or some significant sabotage) felt worthwhile

>A comment that I heard recently is that in some places using solar panels is literally cheaper than using wood panels for fences.

...that might have been my comment. Or someone else repeating it. I was wrong, I misremembered "in X years solar is projected to be cheaper than wood panels for fences". X being, IIRC, maybe 3 years?

The point still stands, but the fact doesn't. Not til ~2028.

At 45°N 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.

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/

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/

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.

Combine it with the desert reclamation efforts finding success pushing back the Sahel, and it could be amazing

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.

So far we dont have any industries popping up, other than battery storage. Intermittent power means unused capex some of the time which means the thing needs to be cheap. Is there a category that fits?

It's not a new industry but just time based running of water heaters and water pumps is a common usage and was doing timed usage for decades before renewables was a thing, so they just need to adjust their timings.

Seems that some steel production is suitable.

Labor costs remain the limiting factor for me. The numbers only work out well if I DIY most of the work, despite being in one of the two or three most expensive electricity markets in the US. Like, the panels could be free and it'd barely change this, the labor's so expensive.

The other discouraging part is that as I understand it it's tricky to build the systems out a little at a time, e.g. start with five panels and no battery, add another five panels and batteries to the mix a few months later, add another ten panels another year later, stuff like that, without ending up with a lot of duplicated equipment and kind of a mess of an installation.

While they're more expensive, microinverters help a lot with having a more flexible install plan a few panels at a time because you just buy one inverter per panel. Also helpful if you have shading issues where a little bit of shade won't ruin a whole string of power generation.

Especially if you're not trying to achieve an off-grid/backup solution, microinverters keep your install and additions simple.

https://enphase.com/store/microinverters

Also, when you start small you don't need or have any use for a battery. Produce less than you consume or be happy with a little bit of waste and you don't need the complexity of a battery.

There are plenty of well planned paths towards a slow accumulation of pieces and features.

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.

> 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

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.

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.

> Isn't that the same thing?

Yes, it’s a joke.

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.

You're assuming that the bifacial panels have their faces pointing north/south; they can also be highly effective oriented east/west, so that they maximize power production in the morning and evening.

(Also: if the panels do have a "preferred" orientation, you can offset that by installing them in an alternating pattern, or at random.)

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.

> 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.

I also believe vertical panels produce more than flat panels in the mornings and evenings, thereby giving them anti-duck curve properties.

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.

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.

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.

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).

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.

One overlooked factor is that as well as getting cheaper, panels are getting more efficient. Commonly installed modules are about 50% more efficient than a decade ago.

Just lots of little tweaks continue to add efficiency, even as they are getting cheaper via lots of other little tweaks.

If you installed a panel today, and assumed a bad case panel degredation over time, then the new panel would be as efficient as the decade old panel was on install even after 40 years of use.

If you assume the new panel has good degredation performance it'll outperform the 2015 panel at install time until roughly 2135!

Or to tie it to the current article, vertical panels installed today outperform perfectly pitched panels from 2015.

There are physics-based limits to how high the efficiency can get with one material, but people are already selling modules with extra layers that work around that limit.

I did some analysis on this recently with a load of simulations. If you ignore the sunlight bouncing back from the surface (and I suspect this might still be the case if you don't ignore it), then the best orientation that maximises winter generation is to have the panels pointing towards the equator and tilted to directly face the Sun at its lowest point at noon in winter. Pointing them lower down (like vertically) reduces the generation. If you're reasonably far from the equator then this is still fairly close to vertical, probably good enough for snow to slide off them.

If you're close to the equator, then vertical North-South panels will generate very little indeed.

We need more data on bifacial performance in order to simulate the performance. I've done some experiments with vertical bifacial TOPCon panels, and the lower production vs 45-degree tilt seems to be offset by the lower mounting costs.

I run a solar company, and for ground mount systems the cost of the frames and foundations is more than the panels. With vertical PV it doesn't matter if power production is maximized, what matters is return on investment.

I wonder how much extra work is required to make a vertical panel stay up in a 200kmh cyclone (hurricane for the Americans, typhoon for the Asians)? I saw a flying cow once during Cyclone David, and that wasn't a particularly strong storm. I guess they could be attached at the sides to some other strong structure, but doing that without getting shade on the panel could be tricky.

need a slab of concrete and some steel to attach the panels to that. probably a lot in dollar terms.

> 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.

Nice example of hacker humor.

We've researched sun tracking vs fixed angle installations deeply in the early 2000s. Our conclusion back then was that sun tracking was not worth it for us mainly because we could not produce it both cheaply enough and make it reliable over the projected lifetime enough to not eat the additional profits from the better yield of tracking.

The bi-facial vertical solution seems to be similar in spirit. Forgo the theoretical additional advantage of better angles for higher reliability (no sweeping required).

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.

A newish solar farm near here has fixed panels https://maps.app.goo.gl/DCw7DfNb5bDTRu1E9

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.

They also better resist bad weather, like hail

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.

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

Solar panels are cheap. A single mirror that size likely will cost more than the panel itself.

Why would it be? All you need is an aluminum PVD or plated piece of plastic with a protective coating. Should be pretty cheap.

Coroplast and aluminized boPET should be a perfectly adequate mirror.

I’m not sure I am understanding how 77% is totally awesome if tilted panels produce 90%, but could the vertical panel efficiency not be improved by putting some reflective material at a tilt towards the vertical panels?

Also, couldn’t the tilted bi-sided panels also have some reflector send light to the rear side?

How do vertical panels handle wind loads?

Two axis panels put themselves vertical on high winds, but facing perpendicular to the wind direction. So it depends on the wind direction.

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.

Could it be feasible to have a program where you purchase solar panels on some farm somewhere and then whatever their power output is you get discounted on your electric bill?

Residential solar power is never going to take off. Everything I’ve seen about it is a scam: you finance a massive purchase and then you pretty much spend the next 30 years paying for panels that you can’t take with you when you move and you can’t even sell the home while it has a lien from the solar company. And on top of that you spend so much money it takes forever to break even anyway. Pointless.

And the panels ruin the aesthetics of your house! Fuck this.

If you could have your panels mounted remotely far away then you don’t care what they look like and you can even move to a new house and still reap their benefits. You could even buy more panels than what your house or apartment could fit.

What's the advantage of the end user financing this? If it would be a good investment for an individual, surely it would be an even better investment for institutional money.

The funding of the solar panels would be distributed across lots of smaller players instead of requiring heroic amounts of capital from a few organizations. Why would an institution invest in panels if the return is purely in watts?

But who knows, I’m not a financial engineer so not sure if this works well.

How simple can steerable panels be made? Obviously mechanical steerage introduces weak points. Nothing is without cost.

Pivot mounts stopped making sense when panels were around $10/watt. They're around $1/watt now. Don't bother.

so if you want to capture both early morning and late afternoon sun, and maximise return during the peak of the day, simply install more panels, some upright, and some at the right slant to achieve your goals?

>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.

I'm sure that they mean there's a side A and a side B in some way that I don't quite understand but boy howdy does this sentence seem meaningless absent its context.

How well do they handle wind loading?

This is my main concern too.

The next question is what is the cost and difficulty of creating the foundations necessary to handle the worst wind you can expect?

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?

Looked like a lowest 6% boost in the winter, but more in the summer. Likely makes sense as panel prices decrease.

The rule of thumb is that bifacial increases production by 35% for a 10% cost increase. YMMV.

snow is acting as a mirror. Won't have the effect on green gras.

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.

I am excited to be here while you experience your first pun!

Still need the explanation of what pun I'm missing, but looking forward to seeing what you come up with :)

There's a standard joke about a farmer who wins an award because he is "outstanding in his field". This is a variation on that: https://explainthejoke.com/2022/08/28/above-and-beyond/

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)

In their field?

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.

I'm assuming that's a joke, but who knows.

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.

They're out standing in the field. ...I'll let myself out.

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.

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.

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...

Congrats!

Very short term thinking. How will it improve if no one tries?

Reminds me of the critics of digital photography circa the year 2000.

This might have been correct 30 or 40 years ago, but energy payback time for solar panels has been only a few years since at least the last millennium.

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