PV module rating scheme explained

The solar energy industry now has an independent tool for comparing photovoltaic (PV) modules: the PSI PV Module Rating, a comprehensive, independent rating standard based on lifetime energy production.

Launched by the Principal Solar Institute (PSI) and guided by an advisory board of academic and industry experts, the PSI Rating is designed to help large-scale solar consumers make informed, intelligent comparisons and decisions when selecting PV modules. Its methodology defines the standard for comparing critical characteristics of PV modules between different manufacturers and across product lines.

Given the complexities involved in choosing PV modules, the PSI Rating is long overdue. As the most fundamental component of a solar power plant, PV modules are available in a vast variety of technologies, configurations and specifications; they must produce electrical power under a wide range of environmental conditions, such as low solar irradiance and elevated temperature; and electrical power output differs substantially between modules of the same wattage. What’s more, with so many different manufacturers and types of modules available, making the right choice has been an ongoing challenge.

The PSI Rating helps elevate the solar industry to the level of other mature markets, such as the financial sector, which turns to Standard and Poor’s Ratings for investments, and the air conditioning manufacturing industry, which relies upon SEER Ratings. Because PSI has no affiliation with any PV module manufacturer and no interest in promoting one over another, the rating method is constructed without bias.

Potentially, the PSI Rating will help bring solar into the mainstream energy and finance marketplace by making it easy for solar professionals to know more about different technologies, finance structures and policies so that they can offer better, more valuable solutions to their customers.