Patent ID: 8155899

Claim:
A portable efficiency measurement meter for determining an efficiency of a modular photovoltaic power generation system containing a photovoltaic module circuit and an output power circuit comprising: an irradiance sensor; a temperature sensor responsive to ambient temperature and an elevated temperature associated with absorption of solar radiation emulating a temperature of power generation photovoltaic modules; a communication module; a user interface; and a processor coupled to the irradiance sensor, the temperature sensor, the communication module, and the user interface, wherein the processor is configured to: receive a temperature value from the temperature sensor; estimate a cell temperature of the photovoltaic power generation system based on a temperature value from the temperature sensor; receive a measured irradiance value from the irradiance sensor; estimate a cell irradiance of the photovoltaic power generation system based on measured irradiance value from the irradiance sensor; receive an output power value of the photovoltaic power generation system by user input through the user interface; estimate an actual photovoltaic module power based on the estimated temperature value and the estimated irradiance value; compute a ratio of the estimated actual photovoltaic module power to a rated photovoltaic module power of the photovoltaic power generation system; compute an efficiency metric associated with a conversion efficiency of the photovoltaic power generation system based on the ratio of the estimated actual photovoltaic module power to the rated photovoltaic module power; and report the efficiency metric through the communication module.