Outdoor Solar Testing Facility in Tempe, Arizona

Outdoor Testing Services

Prior to deployment of solar components and systems, beta site testing provides additional quality assurance for suppliers, purchasers, designers and installers. Beta sites are valuable in terms of identifying potential system failure modes and as a validation step in the procurement process.

For many companies, however, it is simply not practical to implement these testing protocols on their own site for a variety of factors such as cost, weather, and space availability. TÜV Rheinland PTL operates a guarded, behind-the-fence, outdoor test facility in Tempe, Arizona for traditional and custom engineering evaluations of solar components and systems. The facility has over 100,000 sq ft. (nearly 10,000 sq. meter) of available working space with 480VAC utility interconnection and process water on site; client installation options includes raw land, or utilize existing fixed-tilt racks, 2-axis solar trackers, or a large pitched rooftop built to California specifications.

This facility is located in one of the sunniest spots on Earth with an average daily irradiance level of 6.5 kWh/m2/day at latitude tilt. Local, experienced engineering staff will assist on PV, CPV, or BIPV projects for grid-tie operation or individual loads, with multiple performance monitoring and reporting options.

Solar thermal testing for all collector and system types is available.

Benefits at a Glance

With TÜV Rheinland as your partner for testing solar components and systems at our outdoor solar test facility in Tempe, Arizona, you can:

  • Rely on assessments made by experienced solar engineering staff located on site
  • Select from a variety of traditional and custom engineering test services
  • Test exposure to high heat, radiation, and dust
  • Use both unlisted and prototype equipment on site
  • Get accelerated studies of real-world degradation and field failures
  • Receive certification for your components and systems from the world’s leading testing service provider for the solar industry
  • Have access to multiple outdoor test facilities in varying climates in a global and regional network, including Tempe, Arizona, US; Bangalore, India; Gyeongsan, Korea; Cologne, Germany; Osaka and Yokohama, Japan; Shanghai, China; and Taichung, Taiwan


Typical services include, but are not limited to:

  • Performance and degradation monitoring
  • Soiling and weathering studies
  • Ground-bonding evaluation
  • Solar tracker accuracy measurements
  • Performance ratio/energy yield assessments
  • Validation of remote communication
  • Interoperability of components/equipment
  • Reliability and durability of components
  • Comparative and blind studies

Custom test programs are also available.

Data Collection and Monitoring Options

Our Outdoor Solar Test Facility features robust data acquisition sensor and testing equipment with methods developed through years of experience in academic research and qualification testing. Facility O&M policies and procedures follow industry best practices for Class A PV Power Plants.

Experienced engineering staff work with you to identify project expectations and tailor deliverables to your requirements. Data can be delivered in raw form (e.g. as Excel, .csv, or Access files), and/or in a post-processed report with relevant characterization results. Periodic data updates and report delivery are common; however, access to “real-time” data can also be arranged.

All sensors and testing equipment are vetted for high-level accuracy with known uncertainty specifications. Redundant weather stations located on site include continuous monitoring of:

  • Total global irradiance, horizontal
  • Total global irradiance, in-plane
  • Direct normal irradiance
  • Total UV radiation
  • Ambient temperature, relative humidity and rainfall
  • Wind speed and direction

Dedicated or custom sensors and testing equipment are also available.