Fan-cooled PV experiment

 

After repairing a contact inside one of my twenty year old PV modules,
I set it out on the shallow roof outside my window for an in-circuit
test. Clear winter day, full noon sun, still air at 45F, panel lying
on its side with a cardboard carton propping it up to face the sun.
The carton was about one-third the length of the panel, and at a
significant angle, so one wouldn't think it would block much
convection airflow. The panel output was connected to a battery bank
in parallel with nine identical panels. As the panel warmed up in the
sun, I watched the output drop by about 33%.

I happened to notice a 110 CFM computer fan on the bench for another
project, and couldn't resist trying it out. I just set it on the roof
behind the panel, blowing lengthwise along the bottom portion of the
panel. Over about five minutes, the current output of the panel went
up by 25%! Without touching anything else, I unplugged the power to
the fan, and watched the current drop back by over 20%. By this time
some haze and a few puffy clouds had rolled in, reducing the heat of
the sun quite noticeably and ending the experiment.

The maximum gain was about half the power consumed by the fan, so I'm
not suggesting fans as the answer, but I'll certainly be looking to
create opportunities for convective airflow behind my PV array.

Has anyone here collected any similar data?

Loren

 



     In the right climate (not mine) a bit of water mist might be a good idea.

Vaughn

 

I had my solar thermal panels pop a fitting and a 1/2" copper pipe
with a big Grundfos pump behind it pumping a steady stream of water
down a couple of PV panels from the eaves. Would that count?

LOL

 

Loren Amelang wrote:

Ah, another person who has learned a valuable lesson. Care must be taken
in the placement and installation of PV panels.

--
Posted via a free Usenet account from http://www.teranews.com

 



     So what do you do to keep them cool so that they will put out max power,
place them in the shade?

Vaughn