Renewable energy projects — utility-scale solar farms, distributed solar installations, wind farms, and battery energy storage systems (BESS) — require specialized wire and cable rated for outdoor exposure, underground installation, DC circuits, and the unique electrical characteristics of inverter-based power systems. A single 100 MW solar farm can consume hundreds of thousands of feet of PV wire, medium-voltage collector cable, and grounding conductor.
Ramcorp Wire & Cable supplies cable products used across renewable energy projects — from PV wire (primary standard) and USE-2 where permitted for DC string wiring through medium-voltage cable for collector systems and project substations, tray cable for inverter pads and equipment buildings, and underground distribution cable for array wiring and site infrastructure.
Cable Types Used in Renewable Energy & Solar
Renewable energy installations require cable for DC array wiring, AC collection systems, power conversion equipment, underground distribution, grounding, and communications. The table below covers the primary cable types used across solar, wind, and energy storage projects.
| Cable Type | Function | Common Specs | Where It's Installed |
|---|---|---|---|
| PV Wire (primary standard) / USE-2 (where permitted) | DC string wiring from solar modules to combiner boxes or string inverters | 10–12 AWG (string), 6–2/0 AWG (home run), 600V DC or 2 kV DC, sunlight resistant, direct burial rated | Module-to-module connections, string home runs to combiners, DC side of inverters |
| Medium-Voltage Cable (MV-105) | AC collector system from inverters to project substation, wind turbine feeder cables, facility-level interconnections | 5 kV – 35 kV, 1/0 AWG – 1000 kcmil, copper or aluminum | Underground collector circuits, inverter pad to project substation, wind turbine to collector bus, BESS interconnection |
| Building Wire (THHN / THWN-2 / XHHW-2) | AC feeders, branch circuits, inverter output wiring, panel distribution | 14 AWG – 500 kcmil, 600V, 90°C | Inverter AC output to step-up transformer, combiner panel feeders, O&M building circuits |
| Tray Cable (TC-ER) | Power and control in cable tray at inverter pads, substations, equipment buildings | 14 AWG – 2/0 AWG, 600V, sunlight resistant | Inverter pad cable tray, BESS container wiring, substation control buildings |
| Underground Distribution Cable | Underground AC and DC circuits across the project site | Direct burial or conduit depending on project design and EPC standards; UF-B or USE-2 for direct burial; XHHW-2 for conduit; 600V, moisture resistant | DC home runs, AC collector feeders in conduit, site lighting, perimeter security circuits |
| Grounding & Bonding Conductor | Equipment grounding, array grounding, grounding electrode conductors | Bare copper or green-insulated, 6 AWG – 4/0 AWG (and larger for utility-scale ground grids) | Module frame grounding, inverter grounding, tracker grounding, substation ground grid |
| Instrumentation Cable | Monitoring systems, meteorological stations, irradiance sensors, tracker control systems (more limited use in solar compared to industrial facilities) | 16–22 AWG, twisted pair, foil shield (with optional braid depending on noise environment), 300V | Weather stations, tracker motor controls, SCADA RTUs, inverter monitoring |
| Network Cable (Cat6 / Cat6A) & Fiber Optic | SCADA communications, inverter monitoring, site network backbone | Cat6/Cat6A for local runs; fiber optic for backbone and long-distance communications; outdoor-rated, shielded where required | Between inverters and site SCADA, O&M building, data acquisition systems, long inter-equipment runs |
| Tracer Wire | Underground utility locating for non-metallic conduit | 12–14 AWG, solid copper, HDPE jacket | Alongside PVC conduit runs throughout the solar array and to the substation |
Cable by Project Type
Cable requirements vary depending on the renewable energy technology and project scale. The table below maps cable types to each project type and the key electrical considerations.
| Project Type | Typical Setup | Primary Cable Types | Key Considerations |
|---|---|---|---|
| Utility-Scale Solar | 10 MW – 1 GW+ ground-mounted PV arrays with central or string inverters | PV wire, MV cable (collector system), building wire, tray cable, grounding conductor, underground cable, tracer wire | Massive cable volumes, underground MV collector circuits, NEC 690, DC voltage ratings (1000V or 1500V DC systems), rapid shutdown compliance |
| Commercial & Industrial Solar | 100 kW – 10 MW rooftop or ground-mounted systems on commercial properties | PV wire, building wire, tray cable, grounding conductor | Roof conduit runs, rapid shutdown per NEC 690.12, string inverter wiring, existing panel integration |
| Wind Farms | Onshore wind turbine arrays with underground collector systems | MV cable (collector and feeder), building wire (turbine internals), underground cable, grounding conductor, instrumentation cable | Long MV underground runs between turbines, turbine-to-collector bus, step-up transformer connections, harsh outdoor exposure |
| Battery Energy Storage (BESS) | Utility-scale or commercial battery systems co-located with solar or standalone | MV cable, building wire, tray cable, grounding conductor, instrumentation cable, network cable | High DC current within containers, inverter/PCS connections, thermal management circuits, fire detection and monitoring systems within BESS enclosures, NEC 706 (Energy Storage Systems) |
| Community & Distributed Solar | Community solar gardens, distributed generation installations | PV wire, building wire, underground cable, grounding conductor | Grid interconnection requirements, underground conduit to point of interconnection, utility metering, local AHJ requirements |
Key Considerations for Renewable Energy Cable
NEC Article 690 — Solar Photovoltaic Systems
All solar PV installations must comply with NEC Article 690, which governs conductor sizing, overcurrent protection, grounding, disconnects, and rapid shutdown requirements for PV systems. Key cable-related requirements include: PV wire must be listed and labeled for the application, DC conductors must be rated for the maximum system voltage (typically 600V, 1000V, or 1500V DC), and rapid shutdown per NEC 690.12 may require additional conductors or communication cable for module-level shutdown devices. The 2023 NEC introduced Article 706 for energy storage systems with additional cable requirements for BESS installations.
DC Cable Ratings & PV Wire
Solar DC circuits operate at voltages and conditions distinct from standard AC building wiring. PV wire is the primary standard for solar DC circuits — rated for the maximum system voltage (including cold-temperature voltage rise per NEC 690.7), sunlight resistant, and suitable for wet locations. USE-2 cable may be used where permitted for DC circuits where it meets the voltage and environmental ratings. Standard THHN is not rated for DC PV circuits exposed to sunlight. Modern utility-scale solar farms increasingly use 1500V DC systems, requiring cable specifically rated for 2 kV DC service.
MV Collector System Cable
Utility-scale solar and wind projects use underground medium-voltage cable to collect power from distributed inverters or turbines and deliver it to the project substation. Collector system design determines cable sizing, circuit routing, and duct bank configuration. MV cable selection must account for system voltage (typically 15 kV or 34.5 kV), conductor sizing based on inverter output capacity, soil thermal resistivity for ampacity calculations, and the number of circuits in shared duct banks. See our MV-105 Cable guide for detailed selection criteria.
Underground Installation
Renewable energy sites — particularly solar farms and wind farms — rely heavily on underground cable. DC home runs from combiner boxes to inverters, AC collector circuits, and site infrastructure all run underground in direct burial or conduit depending on project design and EPC standards. Cable must be rated for wet locations and installed at minimum cover depths per NEC Table 300.5. Duct bank designs for collector systems must account for mutual heating effects on ampacity. Tracer wire is required alongside non-metallic conduit per most codes.
Grounding & Bonding
Renewable energy systems require extensive grounding and bonding — every module frame, tracker structure, inverter enclosure, and metallic component must be bonded to the equipment grounding system. Utility-scale solar farms can consume thousands of feet of bare copper grounding conductor for the array ground grid alone, with larger conductors required for utility-scale ground grids. Grounding electrode conductors connecting the system to the grounding electrode (ground rods, ground ring) must be sized per NEC 250. Proper grounding is critical for personnel safety, equipment protection, and code compliance.
Buy American & Project Requirements
Renewable energy projects receiving federal tax credits, grants, or direct funding may be subject to domestic content requirements under the Inflation Reduction Act (IRA) or other federal programs. Wire and cable manufactured in the United States may qualify toward domestic content thresholds. Ramcorp stocks Made in USA wire and cable from domestic manufacturers and provides country-of-origin documentation for projects requiring domestic content verification.
Related Guides & Resources
- MV-105 Medium Voltage Cable Overview (5 kV – 35 kV)
- Direct Burial Cable: Types, Depth Requirements & Selection
- THHN vs THWN Building Wire: Ratings & Applications
- AWG Wire Gauge Guide: Sizes, Ampacity & Selection
- Tray Cable Applications & Selection Guide
- Tracer Wire for Underground Utilities
- Instrumentation Cable Guide
- Made in USA Wire & Cable: Why It Matters for Export
- How to Choose the Right Cable for Your Project
Frequently Asked Questions
What cable is used in solar farm construction?
Solar farms use PV wire (primary standard) or USE-2 where permitted for DC string wiring from modules to combiner boxes and inverters, medium-voltage cable (MV-105) for the AC collector system from inverters to the project substation, building wire for AC feeders and branch circuits, tray cable at inverter pads and equipment buildings, bare copper grounding conductor for the array ground grid, and underground cable for site distribution. Cable volumes scale significantly with project size — a 100 MW solar farm can require hundreds of thousands of feet of PV wire and MV cable.
What is the difference between PV wire and standard building wire?
PV wire is the primary standard for solar photovoltaic DC circuits — rated for DC voltage (600V, 1000V, or 2000V DC), sunlight resistant, and suitable for wet locations. Standard THHN building wire is rated for AC circuits and is not suitable for exposed DC PV circuits. USE-2 cable may be used where permitted for some PV applications where it meets the voltage and environmental ratings. Always verify that cable is listed and labeled for the specific PV application per NEC 690.
What cable is used for wind farm collector systems?
Wind farm collector systems use underground medium-voltage cable (typically 15 kV or 34.5 kV) to connect individual wind turbines to the project substation. Cable is installed in underground conduit or direct burial depending on the project design and EPC standards. Collector circuit cable sizing depends on the number of turbines per circuit, turbine output capacity, and soil thermal resistivity for ampacity calculations.
Do renewable energy projects require Buy American cable?
Renewable energy projects receiving federal incentives under the Inflation Reduction Act (IRA) may be subject to domestic content requirements. Wire and cable manufactured in the United States can qualify toward domestic content thresholds. Ramcorp stocks Made in USA cable and provides country-of-origin documentation for projects requiring domestic content verification.
Does Ramcorp supply cable for renewable energy projects?
Yes. Ramcorp Wire & Cable supplies PV wire, medium-voltage cable, building wire, tray cable, underground distribution cable, grounding conductor, instrumentation cable, network cable, fiber optic cable, and tracer wire for utility-scale solar, commercial solar, wind farms, battery energy storage, and distributed generation projects. We support large-volume orders with competitive pricing and delivery coordination for multi-phase builds.
Need Cable for a Renewable Energy Project?
Whether you're developing a utility-scale solar farm, building a wind project, installing a BESS system, or deploying commercial rooftop solar, our team can help with product selection, domestic content documentation, volume pricing, and delivery coordination. We respond to quote requests within one business day.
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Disclaimer: This guide is provided for informational purposes only and is not installation advice. Installing wire & cable can be dangerous and pose a risk of possible electric shock or other hazards. Specifications, availability, and pricing are subject to change without notice. Always verify product specifications with the manufacturer's current datasheet before ordering. Consult a licensed professional for installation advice.
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