sliding solar panels

System

i am an architecture student in İstanbul Technical University, from Turkey.
in my ecological house project, i am working on some new ideas for using this panels. i am searching for using solar panels as sliding facade.
the second idea is using solar panels on the surface of jalousie. its alterable angles is substance of this idea. i attach some sketches about these. i will be waiting your opinions. thanks.

crewzer

Re: sliding solar panels

Stardust,

Interesting ideas!

The designs for the Solar Decathlons held in Washington, D.C., USA might be of interest to you.

See: http://www.solardecathlon.org/
and: http://www.solardecathlon.org/homes_gallery.html
and especially: http://www.solardecathlon.org/homes_gallery.html#darmstadt

More info on the TU Darmstadt entry: http://www.inhabitat.com/2007/10/19/solar-decathlon-technische-universitat-darmstadt/

Info on the PV "shutters" (jalousie): http://www.solardecathlon.de/index.php/our-house/the-shell/

Hope this helps,
Jim / crewzer

BB.

Re: sliding solar panels

One thing to remember is that you will want to keep any shadows/shading off of the active solar PV panels (at the very least, no shadows between 9am to 3pm, summer/winter). The panels' voltage/current drop very quickly if even on or two cells are shaded (in a panel with ~36 cells).

Solar thermal panels (hot air/hot water) are more tolerant of shading and more efficient (watts per square meter/foot) at collecting energy (solar PV electric panels are around ~12% vs solar thermal which can be upwards of 80% efficient). Also, it is very common to install solar thermal panels more vertical--typically you want them to collect as much heat during winter days and less heat in the summer (prevent them from overheating).

In any case, since electrical wire/hot water piping/hot air ducting would be connected to these solar shutters--you would need to take flexing/bending at the "hinge" area and safety into account (broken electrical wires, near boiling water, and people).

-Bill

niel

Re: sliding solar panels

i think what bb is trying to say is that they are stacked so close to one another that they will shade each other. shading is not good. i had a similar idea of using them as a shading over my windows like your idea, but only one longer layer to avoid shading other pvs. it would simply be a large overhang to the window that doubles as a source of power. in winter the angle is adjusted and the sun not only hits the pvs at a better angle, but some sun can then enter the home too. in summer the sun isn't able to enter the home and the sun angle is again optimized better for the season. i did mount my pvs to the house in a none windowed area and it worked. i just didn't implement it to the window area as i have several different sized windows so more planning would be needed on my part.

al128

Re: sliding solar panels

have you thought about making the whole house rotate with the sun????


(yes, I AM serious

cheers
al

niel

Re: sliding solar panels

that is not physically or financially feasable, well at least not for me anyway:p.

BB.

Re: sliding solar panels

I was also concerned that the vertical / uprights on the each side of the shutter could also shade the panels too if the shutters are not flush or protruding from the mounting frame work.

With solar PV panels--any shading will dramatically reduce the panels output.

-Bill

System2

Re: sliding solar panels

al128 wrote: »

have you thought about making the whole house rotate with the sun????


(yes, I AM serious

cheers
al

like Fisher's rotating skycreaper, isn't it?
my project is building an ecological house and we have some restriction about cost.i cabt rotate whole house but i can rotate my panels.
thank you.

System2

Re: sliding solar panels

you say that they can shade each other.
I* distance between two horizontal panels
II* wideness of a panel
III* adjustable angle of panels
i have to calculate the optimum distance and wideness -first and second question-

the midday sun (about 11 am to 3 pm) has right angle sunlight. so i change my panels angle more paralel to horizon.in the evening or early morning, the angle must be more vertical to meet more sunlight.
(left: midday sketch
mid: morning or evening sketch)

in addition, every unit of panels can be slide left or right. it can be in front of the concrate wall, or window. so i have different type of facade, different spaces to view and different spaces to lighting.
(right: different type of facade with sliding each panel sketch)

Solar Guppy

Re: sliding solar panels

You have drawn the panels inside the window opening as drawn, it won't work. Any part of the panel behind the exterior surface will have some amount of shading, which for PV panels means no power output, even with only a small percentage of the panel shaded

Also, the Sun is at different angles throughout the day and seasons, again you will have shading ( top to bottom ) regardless if its in an opening or 100% on the exterior most of the year

Try making a model with cardboard, and your test is to make sure none of the surfaces are shaded.

System2

Re: sliding solar panels

its not inside of the window, may be my sketches say so. in fact, its exterior.
Sunlight first face with panels.

by the way, english is not my first language. So, sorry for my missing.

BB.

Re: sliding solar panels

StarDust,

You English is just fine.

Just one question (probably "English" related)--Questions were not that the solar panels were "behind the window" (sun, window, then panel)--but that your drawings show the solar panels mounted "inside" the left and right vertical frame rails.

Not a problem if the openings/panels face south and the sun is at noon--but they will cast (throw) shadows on the moving shutters/panels when the sun is before 9-10am and after 2-3pm--causing output voltage/currents to fall a lot.

A suggestion would be that the panels not be "hinged in the middle" but at the top edge on the "front face" of the left and right mounting so that there is no morning/evening shading on the panels...

Something else to consider would be to use larger panels mounted vertically and at an angle instead of horizontally as drawn. May not look nice and you don't want to do this--but in "real life" having larger panels that better track the sun with less moving parts/electrical connections might be a better solution (but this has issues too--panels cannot be right next to each other because they will shade each other when the sun is not at high noon.

As long as you don't have any shadows/shading on the "active" portions of the solar PV electric panels--you should be OK.

And remember that you need electric wiring (and fusing, junction boxes) to each panel--and that there will be a fair amount of electric voltage/current on each panel--such that if a wire or panel is broken--there is the possibility of shock/electrocution.

I don't know how deep into the electrical side of your project you will go--but you can address some of the issues by the type of Solar Power Inverter/Charger you will be using.

If you use "Grid Tied" inverter (directly connected to your electric mains, no batteries), then the panel voltages can be 200-600 VDC...

If you do an "Off Grid" type system (solar charger, batteries, inverter), the maximum solar panel voltage can be just a few volts over the battery bank voltage. Example, a 24 volt battery bus will have have panels under 50 volts... Most safety organizations consider above 50-60 volts (AC or DC) to be unsafe and wiring would need to be in metal conduit (pipes) and such to prevent people from touching exposed wiring.

You may also need to address what shutters are used for... In many countries/locations, shutters are used to prevent storm damage and secure a building (such as a vacation home) against theft. Solar Shutters certainly do not do either.

Also, having lots of expensive solar electric panels at ground level could expose them to damage by "kids" and theft. Something else that may need to be addressed.

-Bill