Solar installation quality can be illusive


Evaluating the quality of a residential or C&I solar installation can be a tricky process, given varying practices for such tasks as grid tie connection, with diverse requirements from city to city and state to state. One organization that has sought to standardize PV installation inspections is the Cadmus Group, a Massachusetts-based consultancy.

To comprehensively review installations, Cadmus utilizes its proprietary PV Quality Evaluation and Scoring Tool (PVQuest), an online secure database application that tracks and reports on more than 850 of the most common PV installation deficiencies. The five-year-old database now contains about half of the 8,000 solar inspections the company has cumulatively conducted, says Matt Piantedosi, the manager of solar field operations for Cadmus.

One feature of the software, which can be used on an iPad, is the inclusion of a repair log for the installer, including a photo attachement that can confirm that the repair was made. Cadmus has worked with some solar manufacturers to help them focus on installation problems specific to their products, Piantedosi says.

Among clients is the New York State Energy Research and Development Authority (NYSERDA), which has used Cadmus as a quality assurance inspector for the NY-Sun solar rebate program. As part of the program, Cadmus has inspected over 3,500 solar PV installations, ranging from small residential to large commercial scale. The inspections are required in order to receive the program rebate.

Inspection results seem shocking at times. Working for the Rhode Island Commerce Corp. to inspect renewable energy installations involved in the state’s Renewable Energy Growth program, Cadmus reported in April that it found 41% of all installations exhibited major or critical installation deficiencies. These deficiencies were expected to cause immediate or short- term risks of system failure, reduced operating capacity, or pose a safety hazard.

In the report, authored by Cadmus staff Danielle Burns, Tyler Orcut, Shawn Shaw, and Piantedosi, Cadmus found 557 installation errors across all 90 systems inspected. Many of the issues identified were classified as minor or incidental code violations, such as labeling. But most installation deficiencies, and the most severe, occurred at the PV array and point of interconnection. Issues such as grounding, labeling, and wire management appeared most frequently.

Among recommendations for improving installation quality, Cadmus underscores the need for training of local permitting and inspection authorities, installers, and utility personnel. Cadmus also called for clarification of jurisdictional or utility program technical requirements, and documentation to reduce confusion regarding interconnection requirements, in particular.


Interested in quality issues? Be sure to join pv magazine for our Quality Roundtable at the Solar Power International trade show on September 12. More information and registration can be found here.

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