Offshore and floating solar installations have seen rapid growth as developers seek to utilize underused water surfaces and reduce land competition. The floating solar PV market was valued at USD 7.7 billion in 2024 and is projected to grow steadily in the coming decade, driven by technological advances in materials and mooring systems as well as supportive policies in many regionsIn this context, marine photovoltaic cables become critical components: they must withstand harsh saltwater, UV exposure, mechanical stress from waves, and biofouling over long service lives. The 2PfG 2962 standard from TÜV Rheinland (leading to the TÜV Bauart Mark) specifically addresses these challenges by defining performance testing and certification requirements for cables in marine PV applications
This article examines how manufacturers can meet 2PfG 2962 requirements through robust performance testing and design practices.
1. Overview of the 2PfG 2962 Standard
The 2PfG 2962 standard is a TÜV Rheinland specification tailored for photovoltaic cables intended for marine and floating applications. It builds on general PV cable norms (e.g., IEC 62930 / EN 50618 for land-based PV) but adds stringent tests for saltwater, UV, mechanical fatigue, and other marine-specific stressors. The standard’s objectives include ensuring electrical safety, mechanical integrity, and long-term durability under variable, demanding offshore conditions. It applies to DC cables rated typically up to 1,500 V used in near-shore and floating PV systems, requiring consistent production quality control so that certified cables in mass production match the tested prototypes
2. Environmental and Operational Challenges for Marine PV Cables
Marine environments impose multiple concurrent stressors on cables:
Saltwater corrosion and chemical exposure: Continuous or intermittent immersion in seawater can attack conductor plating and degrade polymer sheaths.
UV radiation and sunlight-driven aging: Direct sun exposure on floating arrays accelerates polymer embrittlement and surface cracking.
Temperature extremes and thermal cycling: Daily and seasonal temperature variations cause expansion/contraction cycles, stressing insulation bonds.
Mechanical stresses: Wave motion and wind-driven movement lead to dynamic bending, flexing, and potential abrasion against floats or mooring hardware.
Biofouling and marine organisms: Growth of algae, barnacles, or microbial colonies on cable surfaces can alter thermal dissipation and add localized stresses.
Installation-specific factors: Handling during deployment (e.g., drum unwinding), bending around connectors, and tension at termination points.
These combined factors differ markedly from land-based arrays, necessitating tailored testing under 2PfG 2962 to simulate realistic marine conditions
3. Core Performance Testing Requirements under 2PfG 2962
Key performance tests mandated by 2PfG 2962 typically include:
Electrical insulation and dielectric tests: High-voltage withstand tests (e.g., DC voltage tests) in water or humidity chambers to confirm no breakdown under immersion conditions.
Insulation resistance over time: Monitoring insulation resistance when cables are soaked in saltwater or humid environments to detect moisture ingress.
Voltage withstand and partial discharge checks: Ensuring that insulation can tolerate design voltage plus safety margin without partial discharge, even after aging.
Mechanical tests: Tensile strength and elongation tests of insulation and sheath materials following exposure cycles; bending fatigue tests simulating wave-induced flexing.
Flexibility and repeated flex tests: Repeated bending over mandrels or dynamic flex test rigs to mimic wave motion.
Abrasion resistance: Simulating contact with floats or structural elements, possibly using abrasive mediums, to assess sheath durability.
4. Environmental aging tests
Salt spray or immersion in simulated seawater for extended durations to evaluate corrosion and polymer degradation.
UV exposure chambers (accelerated weathering) to assess surface embrittlement, color change, and crack formation.
Hydrolysis and moisture uptake evaluations, often via prolonged soak and mechanical testing afterward.
Thermal cycling: Cycling between low and high temperatures in controlled chambers to reveal insulation delamination or micro-cracking.
Chemical resistance: Exposure to oils, fuels, cleaning agents, or anti-fouling compounds commonly found in marine settings.
Flame retardancy or fire behavior: For specific installations (e.g., enclosed modules), checking that cables meet flame propagation limits (e.g., IEC 60332-1).
Long-term aging: Accelerated life tests combining temperature, UV, and salt exposure to forecast service life and establish maintenance intervals.
These tests ensure cables retain electrical and mechanical performance over the expected multi-decade lifetime in marine PV deployments
5. Interpreting Test Results and Identifying Failure Modes
After testing:
Common degradation patterns: Insulation cracks from UV or thermal cycling; conductor corrosion or discoloration from salt ingress; water pockets indicating seal failures.
Analyzing insulation resistance trends: A gradual decline under soak tests may signal suboptimal material formulation or insufficient barrier layers.
Mechanical failure indicators: Loss of tensile strength post-aging suggests polymer embrittlement; reduced elongation indicates stiffness increase.
Risk assessment: Comparing remaining safety margins against expected operating voltages and mechanical loads; assessing if service life goals (e.g., 25+ years) are achievable.
Feedback loop: Test outcomes inform material adjustments (e.g., higher UV stabilizer concentrations), design tweaks (e.g., thicker sheath layers), or process improvements (e.g., extrusion parameters). Documenting these adjustments is crucial for production repeatability.
Systematic interpretation underpins continual improvement and complianc
6. Material Selection and Design Strategies to Comply with 2PfG 2962
Key considerations:
Conductor choices: Copper conductors are standard; tinned copper may be preferred for enhanced corrosion resistance in saltwater environments.
Insulation compounds: Cross-linked polyolefins (XLPO) or specially formulated polymers with UV stabilizers and hydrolysis-resistant additives to maintain flexibility over decades.
Sheath materials: Robust jacketing compounds with antioxidants, UV absorbers, and fillers to resist abrasion, salt spray, and temperature extremes.
Layered structures: Multilayer designs may include inner semiconductive layers, moisture barrier films, and outer protective jackets to block water ingress and mechanical damage.
Additives and fillers: Use of flame retardants (where required), anti-fungal or anti-microbial agents to limit biofouling effects, and impact modifiers to preserve mechanical performance.
Armor or reinforcement: For deep-water or high-load floating systems, adding braided metal or synthetic reinforcement to withstand tensile loads without compromising flexibility.
Manufacturing consistency: Precise control of compounding recipes, extrusion temperatures, and cooling rates to ensure uniform material properties batch-to-batch.
Selecting materials and designs with proven performance in analogous marine or industrial applications helps meet 2PfG 2962 requirements more predictably
7. Quality Control and Production Consistency
Maintaining certification in volume production demands:
In-line inspections: Regular dimensional checks (conductor size, insulation thickness), visual inspections for surface defects, and verifying material batch certificates.
Sample testing schedule: Periodic sampling for key tests (e.g., insulation resistance, tensile tests) replicating certification conditions to detect drifts early.
Traceability: Documenting raw material lot numbers, compounding parameters, and production conditions for each cable batch to enable root-cause analyses if issues arise.
Supplier qualification: Ensuring polymer and additive suppliers consistently meet specifications (e.g., UV resistance ratings, antioxidant content).
Third-party audit readiness: Maintaining thorough test records, calibration logs, and production control documents for TÜV Rheinland audits or re-certification.
Robust quality management systems (e.g., ISO 9001) integrated with certification requirements help manufacturers sustain compliance
long-term
Danyang Winpower Wire and Cable Mfg Co., Ltd.’s TÜV 2PfG 2962 Certification
On June 11, 2025, during the 18th (2025) International Solar Photovoltaic and Smart Energy Conference and Exhibition (SNEC PV+2025), TÜV Rheinland issued a TÜV Bauart Mark type certification certificate for cables for offshore photovoltaic systems based on the 2PfG 2962 standard to Danyang Weihexiang Cable Manufacturing Co., Ltd. (hereinafter referred to as “Weihexiang”). Mr. Shi Bing, General Manager of Solar and Commercial Products and Services Components Business of TÜV Rheinland Greater China, and Mr. Shu Honghe, General Manager of Danyang Weihexiang Cable Manufacturing Co., Ltd., attended the awarding ceremony and witnessed the results of this cooperation.
Post time: Jun-24-2025