Outlines the industry's first and only comprehensive, independent performance rating standard

Dallas, TX – November 13, 2012 -- Principal Solar, Inc (PSI; OTC Pink: PSWW), a publicly traded solar energy holding company executing a unique roll-up strategy to create the world's first distributed solar utility, today announced the release of "Solar Industry Goes Mainstream: New PV Module Rating System Empowers Solar Professionals," authored by Ken Allen, Rick Borry, Dan Bedell, Kirk Blankenship and Matthew A. Thompson, director of The Principal Solar Institute, an online reference center and resource guide for the commercial and utility scale solar market. The paper outlines the industry's first and only comprehensive, independent performance rating standard based on lifetime energy production of solar photovoltaic (PV) modules, which is designed to assist large-scale solar consumers.

"Solar PV modules offer a vast array of technology choices in terms of cells, panels and configurations, creating challenges for decision-makers," says Thompson. "This unbiased rating system elevates 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."

Guided by an advisory board of highly influential academic experts and solar professionals, the PSI PV Module Rating is based on physical tests by independent laboratories such as T ÜV Rheinland, but is presented as a single comparative number that can be used with circumstantial information such as deliverability, pricing and manufacturer reputation so that solar power plant designers, buyers and financiers have a consistent basis for choosing a particular PV module. The system empowers these decision-makers to make informed, intelligent comparisons and determinations when selecting PV modules.

"The PSI Rating method will satisfy the solar power industry's urgent need for a way to uniformly evaluate PV modules in order to make technologically and financially optimal decisions," Thompson adds.

About Principal Solar
Principal Solar, Inc (PSI; OTC Pink: PSWW), is a publicly traded solar energy holding company executing a unique roll-up strategy to create the world's first distributed solar utility. PSI concentrates its resources on the acquisition, finance, development and management of solar power companies. The Principal Solar Institute, an educational organization created by Principal Solar, Inc., is dedicated to spreading solar knowledge to the critical stakeholders in the ongoing energy debate. Visit www.PrincipalSolar.com.