PV Through A Window

[Antipodean Bucket Farmer]

Hi Everybody,

Being in a rented apartment, I have serious limitations
on physical stuff. So I am looking for ways around
that, to develop skills/experience...

My flat faces just slightly off of north (I am in the
S. Hemisphere, so that is good.)

I have large windows of single-pane glass (recently
replaced.)

How much reduction in efficiency should I expect if I
mount a PV panel on the inside of the window, vs. on
the outside?

Thanks...

 

[ptaylor]

Hi Everybody,

Being in a rented apartment, I have serious limitations
on physical stuff. So I am looking for ways around
that, to develop skills/experience...

My flat faces just slightly off of north (I am in the
S. Hemisphere, so that is good.)

I have large windows of single-pane glass (recently
replaced.)

How much reduction in efficiency should I expect if I
mount a PV panel on the inside of the window, vs. on
the outside?

Thanks...

Well,my only experience went thusly...
I have a 10W Solec panel,and had it inside of a window (which did have a
window bug-screen in front of it,further cutting efficiency,i also
experimented with that a bit.) and I could get about 4Watts of power
from it on a sunny day.(with window screen.)
The window faced south(N. Hemishphere),and got a good amount of direct
sunlight.
I later moved it outside,just propped up against the side of the house
right under the window,kinda "eyeballed" it to point at the sun as best
I could and got about 8Watts out..I now leave it outside,50% difference
is quite alot.
Mind you,this is with a small panel,and was just kind of experimental,I
dunno if this would correspond with anyone else's findings/knowledge.
I would atleast suggest removing the window screen,that seemed to make
quite a difference when I tried it.There was probably a good 25%
increase in output without the screen.
So,A ball-park estimate from my limited experience/experimentation would
suggest that the windows may block up to 25% of your available energy.
I don't know how accurate or useful the "guesstimated" numbers from a
single experiment are,but thats my $0.02

 

[Richard P.]

During a service call to a mobile home trailer park, I noticed the customer had a 75 watt Siemens
SP75 pv panel just sitting in his single pane window. I asked him how much current he got out of it
as I noticed it wasn't angled for optimum efficiency, he said he gets about an amp or two during
peak sunlight. He doesn't do much with it and said he kept it when he sold off his RV several years
ago.

I lived in a multi-level apartment for several years while attending school. At first I was
reluctant to do this but after noticing that other tenants were installing their mini-satellite tv
dishes in the ugliest spots, I built a frame for my four pv's and put a bracket on it to hang off
the balcony railing. Had no complaints but a couple of questions by interested individuals wanting
to know how much money I was saving when I told them I was backfeeding it into the grid (I wasn't
but you should see their eyebrows go up when I say that!).

 

[Danno]

Hi Everybody,

Being in a rented apartment, I have serious limitations
on physical stuff. So I am looking for ways around
that, to develop skills/experience...

My flat faces just slightly off of north (I am in the
S. Hemisphere, so that is good.)

I have large windows of single-pane glass (recently
replaced.)

How much reduction in efficiency should I expect if I
mount a PV panel on the inside of the window, vs. on
the outside?

Thanks...

I also rent an apartment, my patio faces west, slightly north. I've just
bolted my panels to the outside of the patio railing, the landlord seems OK
with it. Additionally, I have a 15W panel mounted on some particle board which
is the size of a bedroom window. I replaced the window with this, use it to
charge the smal battery pack there.
I had also originally planned to charge from behind the glass, but the
difference in power generated is significant, there's really no comparing
the two. If you are able, mount them outside under direct sun. I would mount
my big panels flat like a table, but my deck is covered.