Principal Solar, Inc (PSI; OTC Pink: PSWW), a publicly traded solar energy holding company, backs educational organization dedicated to solar industry

Dallas, TX – October 15, 2012 -- The Principal Solar Institute, an online reference center and resource guide for the commercial and utility scale solar market, today announced the introduction of the PSI PV Module Rating, the first-of-its kind approach that allows easy, unbiased, comprehensive analysis and comparison of photovoltaic (PV) modules. PSI Ratings are designed to allow solar consumers to make informed, intelligent comparisons and decisions when selecting PV modules.

The Principal Solar Institute Advisory Board consists of these highly influential academic and industry experts:

*Govindasamy (Mani) TamizhMani, Ph.D., President, TUV Rheinland PTL (Photovoltaic Testing Laboratory), involved in R&D activities related to photovoltaics and fuel cells for over 25 years, and PV module testing and certification activities for over 13 years.

*Robert Birkmire, Ph.D. (Physics), Director, Institute of Energy Conversion (IEC), University of Delaware, Professor, Department of Materials Science and Engineering and Department of Physics, University of Delaware, principal investigator on numerous government and industrial contracts on amorphous and polycrystalline thin film solar cells.

*Robert P. H. Chang, Ph.D. (Astrophysics), Professor, Department of Materials Science and Engineering, Northwestern University, recognized innovator in materials research, interdisciplinary science education and international networking.

*David Williams, Chief Executive Officer of solar developer dissigno, peer reviewer for the US Department of Energy's SunShot program and lead for National Renewable Energy Laboratory's Quality Assurance Communication task force.

"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."

PV modules produce electrical power under a wide range of environmental conditions, such as irradiance, nominal operating cell temperature and ambient conditions causing the electrical power output to differ between modules of the same nameplate wattage. 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.

"Significantly, this method goes beyond simply tabulating results provided by the manufacturers in their specification sheets," adds Dr. Thompson.

Michael Gorton, CEO and chairman of Principal Solar, Inc (PSI; OTC Pink: PSWW), explains, "No industry can be considered mature until it has adopted standards. As tireless, passionate promoters of solar as a near-term solution to so many energy-related issues, the Principal Solar Institute is committed to driving solar energy to the forefront of the national energy debate. These standards will help to build the solar industry's solid foundation of credibility in the minds of energy leaders, investors and industries around the world."

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. Follow us on Twitter: @PrincipalSolar. Visit www.PrincipalSolar.com.