PSI PV Module Ratings were designed so that solar customers could easily make informed and fact-based decisions between different PV modules.
“Until now, there was no accepted standard for comparing the critical characteristics of PV modules between different manufacturers, or even across a single product line,” says Matthew A. Thompson, Ph.D., executive director of the Principal Solar Institute. “The PSI Ratings elevate the solar industry in a rigorous approach similar to the financial sector, which turns to Standard and Poor’s Ratings for investments, and the air conditioning industry, which relies upon SEER Ratings. We are closing the gap in the solar power industry’s urgent need for a method to uniformly evaluate PV modules in order to make technologically and financially optimal decisions.”
Photovoltaic modules are able to create electrical power while under a very wide variety of environmental conditions. These conditions, such as: irradiance, nominal operating cell temperature, and other ambient conditions exert considerable influence over how much electrical power is generated. Even if two different modules have the same nameplate wattage, they may react to different conditions very differently. “The PSI PV Module Rating is a comparative number that can be used with pricing information, providing power plant designers and buyers with a consistent basis for choosing a particular PV module.”