HelioVolta’s report PV connectors: The state of the field highlights the risks of using low-cost connectors in solar installations and provides case studies that describe events, the effects and ultimate cost breakdown.
The report details observations from over 5 GWs of independent field inspections conducted by HelioVolta at hundreds of utility and commercial solar projects in the United States. The main finding is that, even though the National Electrical Code has been revised many times since 2008 to try to reduce connector-related failures, they remain one of the most widespread threats to PV system safety and reliability.
“It’s absurd that one of the cheapest components in a PV system is responsible for the industry’s most notorious failures,” said David Penalva, CEO of HelioVolta. “We’re talking about a dollar’s worth of plastic and metal putting multimillion-dollar assets—and people—at risk. It’s unacceptable.”
To produce the report, HelioVolta analyzed field data, presents connector failure and remediation case studies and shares connector risk mitigation tactics for asset owners, operations and maintenance (O&M) providers, and engineering, procurement, and construction (EPC) teams.
Key findings from HelioVolta’s field inspections include:
- 83% of projects inspected suffered from at least one connector-related issue;
- 45% of sites had major connector issues requiring urgent maintenance;
- 3% of projects faced critical connector failures requiring partial or total system de-energization;
- The majority of issues stemmed from preventable causes such as improper installation.
Major issues are defined as those needing urgent corrective action and include connectors that are intermated, are over or under torqued, show signs of overheating, show exposure to UV or water, are cross threaded, uncapped or damaged in some way.
HelioVolta’s connector-based risk analysis indicates that the number and type of connectors in an installation can increase risk of events by nearly 20 times. Also considered is the impact of module-level power electronics (MLPE), such as optimizers and microinverters. Since 2017 MLPE devices have been required in most U.S. rooftop solar installations because of rapid shutdown requirements. While MLPE devices increase the safety of solar installations, the devices add connectors to the installations, which can create problems if they are not compatible.
The report provides six risk mitigation tactics as a part of engineering and procurement best practices:
- Minimize connectors
- Procure compatible equipment
- Conduct factory oversight
- Provide training
- Validate quality
- Document equipment condition at installation
HelioVolta identified four types of inspection that can be used in regular inspections: visual scan, thermal scan with a hand-held thermal camera, X-ray imaging and X-ray computed tomography (XCT), which produces a 3D computer model.
According to HelioVolta, the findings signal a growing urgency to mitigate risks beginning with implementing procurement specifications to ensure compatibility and following enhanced quality control and O&M procedures. Reducing risks equates to reducing downtime, which lowers maintenance costs and liability exposure, the report finds. It notes that the cost of connector failure and remediation equaled 58% of a commercial solar portfolio’s annual revenues and 19% for a utility power plant.
“Proper connector installation is clearly important, but assessing these components at every preventive maintenance visit is just as vital,” commented Jesse Waters, CEO of Servist Energy, an O&M provider. “Since connector problems become riskier as systems operate, finding and fixing issues before disaster strikes is the best way to avoid high-cost remediation campaigns.”
The report also contains a primer on connectors that explains code requirements and what makes connectors compatible.
The authors describe future advances in connectors that include development of “crimpless” connectors, a Sandia National Laboratory-led effort to standardize connector terminology, and an initiative to develop a universal connector standard from National Renewable Energy Laboratory (NREL),
HelioVolta provides independent technical services that ensure renewable energy assets perform safely and reliably. In its field inspections, HelioVolta uses SolarGrade, a field operations software platform developed by its affiliate, SolarGrade, Inc.
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