Methods and systems for determining soiling on photovoltaic devices
An aspect of the present disclosure relates to radiating light on to a front surface of a glass pane comprising a first surface and a second surface defining a thickness between the first surface and the second surface, wherein the first surface is substantially parallel to the second surface; detecting a transmittance of the light through the glass pane; comparing the transmittance through the glass pane to a reference transmittance value corresponding to a clean reference glass pane; and determining, using the transmittance and the reference transmittance, a soiling metric of a photovoltaic module.
1. A method for determining the soiling ratio of an amorphous silicon (a-Si) photovoltaic cell, the method comprising:
measuring a reference spectral transmittance (τ ref ) at a single wavelength of a glass pane immediately after the glass pane is cleaned;
measuring a soiled spectral transmittance (τ soil ) at the single wavelength of the glass pane;
calculating the spectral transmittance of soiling (τ soiling ) at the single wavelength of the glass pane, using the equation
τ
soiling
=
τ
soil
τ
r
e
f
;
and
assigning a soiling ratio of the a-Si photovoltaic cell to the corrected spectral transmittance of soiling of the glass pane.
2. The method of claim 1 , wherein the single wavelength is within the visible region of light.
3. The method of claim 1 , wherein the single wavelength is 500 nm.
4. The method of claim 1 , wherein the measuring is performed using a light detector.
5. The method of claim 4 , wherein the light detector is the amorphous silicon (a-Si) photovoltaic cell.
6. The method of claim 5 , wherein:
a nearby photovoltaic cell comprises a cover,
the cover is oriented at an angle and is comprised of a first material,
the glass pane is oriented at the angle, and
the glass pane is comprised of the first material.