Water reflection analysis of encapsulated photovoltaic modules
AssigneeThe Regents of the University of California
InventorsDavid Fenning, Rishi Kumar, Guillaume von Gastrow
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Abstract
A method for moisture testing of a fully assembled photovoltaic (PV) module. An assembled PV module is probed with short wave IR probe energy in the range of 1700-2000 nm. Energy reflected from the assembled PV module is collected and directed to a sensor. Noise is removed from a signal of the sensor with reference to the probe energy. Absorption is of the probe energy is determined. The absorption is correlated to moisture in the PV module. A preferred system that carries out the method provides a signal-to-noise ratio (as defined by standard deviation/mean of measured reflectance) of at least 3800.
Claims15
A method for moisture testing of a fully assembled photovoltaic (PV) module, comprising:
- probing the assembled PV module with short wave IR probe energy in the range of 1700-2000 nm;
- collecting energy reflected from the assembled PV module and directing the energy to a sensor;
- removing noise from a signal of the sensor with reference to the probe energy and determining an absorption of the probe energy;
- and
- correlating absorption of the reflected energy to moisture.
A system for moisture testing of a fully assembled photovoltaic (PV) module, comprising:
- a function generator for generate a pulsed reference signal;
- a pulsed light source responsive to the pulsed reference signal to emit probe energy in the range of 1700-2000 nm;
- optics to direct the probe energy upon the assembled PV module;
- optics to collect reflected energy from the assembled PV module;
- a sensor receiving collected reflected energy;
- a lock-in amplifier locked to the pulsed reference signal to attenuate noise in the collected reflected energy;
- and
- electronic analysis to correlate absorption of the probe energy to moisture.
Dependencies are inferred from the claim text.