2
$\begingroup$

Is it possible to simulate a layer of dust deposited on top of a PV cell in a controlled manner?

One potential method I had was to put a given weight of a particulate/powder (chalk powder, talcum powder, etc.) into water, and pour the water on top of the solar panel, letting it dry and thus leaving the powder on top of the panel. Would this be viable, and if so, what would be the best powder to use?

$\endgroup$
3
  • $\begingroup$ What about layers of thin clear or only slightly tinted plastic? Is that controllable with the effect you want? $\endgroup$ – Solar Mike Sep 22 '17 at 13:39
  • $\begingroup$ What's wrong with just dropping dust? Are you forced to run the experiment in an outdoor/windy environment? $\endgroup$ – Carl Witthoft Sep 22 '17 at 14:11
  • $\begingroup$ @CarlWitthoft No, I was just concerned with the controllability of the depositing (i.e. if I want to repeat this across several trials, the amount of dust deposited on the surface needs to be consistent). I am afraid that varying air currents in the room may carry the dust away as I drop it. $\endgroup$ – Andi Gu Sep 22 '17 at 16:37
1
$\begingroup$

A PV cell's system efficiency will vary exactly linearly with the amount of light blocked by the dust. For the particle sizes and wavelengths involved, refraction and multiple scattering effects are minimal. What this leaves you with is a way to "map" dust collection to the equivalent uniform, neutral density filter as SolarMike implied in his comment.

I would recommend setting up two cells, one as a clean reference, and the other with arbitrary dust levels. Make a few measurements and generate a graph of ,say, power loss vs. total volume of powder deposited. You may want to repeat a few times to guarantee more or less uniform distribution of powder over the active area.

$\endgroup$
0
1
$\begingroup$

More to the "even-distribution" question, I'd recommend your idea of water distribution. I'd use spray nozzles - they're designed for relatively even distribution. To that end, I'd recommend IS nozzles (lower budget) or NC nozzles (higher budget), with a distribution manifold. These will provide an easily repeatable test method. Simply dial down to the minimum levels for consistent spray (1 psi for IS, 3.5 psi for NC). Then adjust the concentration of dust in your spray solution. Use a pressure regulator to ensure consistent pressure across the spray system, and a timer to ensure the exact amount of solution sprays across the panels. Finally, as a test to the system, weigh the dried off powder at the end of the experiment on each panel to verify how much dust was deposited on each panel.

For the powder, if you have access to a very low humidity area I'd recommend powdered milk or creamer. Talcum powder is also used readily. But that's mostly a personal opinion.

$\endgroup$
1
  • $\begingroup$ Seems expensive compared to a sheet of plastic , but if someone else is paying the piper.... $\endgroup$ – Solar Mike Sep 22 '17 at 19:02

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.