I've been wondering for a while if vertical solar panels on the sides of buildings might make sense. Today (for no reason that I know of) I started wondering if might even make sense to put panels on parts of a building that don't directly face the sun at all.
That's what lead me to this particular article, which examines the efficiency of putting panels on north facing roofs.
I explored the vertical panel idea in a blog post last year: http://curtisb.posthaven.com/the-solar-garage-door. I don't know if that idea would work, but I was trying to imagine an application of the idea so absurdly simple that a startup could easily use it to bootstrap into a more lucrative market.
> parts of a building that don't directly face the sun at all
Bifacial panels (where one side faces the ground) are almost on the market for solar plants. The ground is generally light colored sand, which is great for diffuse light, so they see ~30% extra insolation for the same silicon.
Generally, you don’t run out of roof space before meeting a 2 story buildings energy needs. On taller buildings installation costs would be significant, coupled with lower effects and it’s more viable to put them just about anywhere else.
The garage door is a rather complex place to put them as their are a huge range of styles and you would need to either fit the opening and replace the mechanism, or design a door for each existing type sold. On top of that wiring up solar to your house is the tricky part not putting something on a roof.
I think it should probably be noted that this analysis is for grid-attached solar, not grid-independent. For the first, you're generally not going to care about the seasonal power profile (you get paid the same for a kW in June or January) and so the north-facing array's production being more heavily loaded into the spring and summer months won't matter. But if you're trying to actually power your house, you probably want all the power you can get in the winter months. Optimizing for minimums, not totals, if that makes any sense...
With the price for solar-panels falling exponentially (1/2 every ~6 years), north facing tiles even in the most extreme examples will become profitable in a few decades or less.
Good rule of thumb is that the best production per panel ratio to get the most utility consumption offset (so you drop to the lowest tier) will return the most savings.
Shaded or North facing panels in the northern hemisphere are almost never worth it. Put what you can on the south and look into a better AC unit, new windows, LEDs, and insulation first.
You've been downvoted but I also noticed the "northern-hemispherism" (to coin a word) in the title. It does get a bit tedious for those of us who live in the southern hemisphere.
It’s not just the charts, “In Minneapolis, a 10/12 pitched roof that is perfectly north-south will have a 57% penalty between the south-facing and north-facing modules.”
Really, you should not complain if you’re badly skimming an article.
This probably applies more to homes with an East to West facing pitch, but I find it really odd that it isn't standard issue to have a track system that moves the solar panels from one side of the roof to the other. A simple track and something basic like a garage door motor would allow the panels to be in a more optimal position throughout the day.
Slightly off topic, but why is there so much discussion about fixed rooftop solar compared to a ground based system with tracking? Seems to me a ground based system would be easier and safer to set up, easier to keep clean, and easier to keep in an optimal position, even if it didn't have tracking. Why have this tight coupling to the roofing system?
It develops that tracking systems are expensive, heavy, and take up a lot of space.
In fact, so much so that the tracking systems rarely make sense with modern panels. You would usually be better off spending the money, weight, and space on more fixed panels than messing with the tracking systems.
For urban residential I wouldn’t give up any area of my small plot of land even if it provided all my electricity and the installation was given to me for free.
A ground based two axis tracking mount that can take the wind loading of six 360W 72-cell (2.0 x 1.0 meter each) panels costs more than the panels. Foundation, concrete, pole, mechanism, etc.
It is much more economical to just buy more panels and mount them at a fixed angle.
[+] [-] curtis|7 years ago|reply
That's what lead me to this particular article, which examines the efficiency of putting panels on north facing roofs.
I explored the vertical panel idea in a blog post last year: http://curtisb.posthaven.com/the-solar-garage-door. I don't know if that idea would work, but I was trying to imagine an application of the idea so absurdly simple that a startup could easily use it to bootstrap into a more lucrative market.
[+] [-] chris_va|7 years ago|reply
Bifacial panels (where one side faces the ground) are almost on the market for solar plants. The ground is generally light colored sand, which is great for diffuse light, so they see ~30% extra insolation for the same silicon.
[+] [-] Retric|7 years ago|reply
The garage door is a rather complex place to put them as their are a huge range of styles and you would need to either fit the opening and replace the mechanism, or design a door for each existing type sold. On top of that wiring up solar to your house is the tricky part not putting something on a roof.
[+] [-] specialist|7 years ago|reply
The south facade of Phoenix's downtown library has adjustable horizontal louvres. Make them out of solar panels for a power and shade two-fer.
https://en.wikiarquitectura.com/building/Burton-Barr-Central...
https://en.wikiarquitectura.com/building/Burton-Barr-Central...
https://en.wikipedia.org/wiki/Burton_Barr_Central_Library
[+] [-] throwsway2525|7 years ago|reply
[+] [-] DuskStar|7 years ago|reply
[+] [-] coldtea|7 years ago|reply
Even so, if you can't have a south-facing module, the fact that you don't lose as much in many circumstances (roof slopes etc) is good to know.
Even when one wants to power their house, there's no need to go in an "all or nothing" approach.
[+] [-] johnhenry|7 years ago|reply
[+] [-] FooHentai|7 years ago|reply
It's the same as having to ROT6 any gardening advice or you'll be planting things at the worst possible time :)
[+] [-] dugditches|7 years ago|reply
[+] [-] singularity2001|7 years ago|reply
[0] http://blog.comparemysolar.co.uk/wp-content/uploads/2013/03/... etc
[+] [-] thedoops|7 years ago|reply
Shaded or North facing panels in the northern hemisphere are almost never worth it. Put what you can on the south and look into a better AC unit, new windows, LEDs, and insulation first.
[+] [-] myroon5|7 years ago|reply
[+] [-] oska|7 years ago|reply
[+] [-] foxhop|7 years ago|reply
https://russell.ballestrini.net/fulfilling-childhood-dreams-...
[+] [-] Johnny555|7 years ago|reply
Is 2/12 common anywhere? Certainly not in any place that gets snow.
(he does give some numbers for other pitches in his charts, but in the teaser paragraph, he uses 2/12)
[+] [-] Retric|7 years ago|reply
Really, you should not complain if you’re badly skimming an article.
[+] [-] unknown|7 years ago|reply
[deleted]
[+] [-] seymour333|7 years ago|reply
[+] [-] unknown|7 years ago|reply
[deleted]
[+] [-] tejohnso|7 years ago|reply
[+] [-] bradknowles|7 years ago|reply
In fact, so much so that the tracking systems rarely make sense with modern panels. You would usually be better off spending the money, weight, and space on more fixed panels than messing with the tracking systems.
[+] [-] alkonaut|7 years ago|reply
[+] [-] walrus01|7 years ago|reply
It is much more economical to just buy more panels and mount them at a fixed angle.
[+] [-] cglace|7 years ago|reply
[+] [-] pjc50|7 years ago|reply
Utility scale has largely abandoned tracking as not cost effective.