TÜV Rheinland PTL is a world-renowned facility for PV technology testing located in Tempe, Arizona, USA. TÜV Rheinland PTL is a partnership between the TÜVRheinland®, a $1.5 billion USD provider of independent testing, assessment, and certification services for industry; and Arizona State University (ASU), one of the leading research and educational institutions in the USA. Locally, the ASU's photovoltaic have been providing testing services to the photovoltaic (solar) power marketplace since 1992.