Solar PV cable buyers in New York

1 kV, 2 kV, and the dual rating

For years the default PV cable rating was 1,000 V DC, matching 1,000 V system designs. As module and string voltages rose to 1,500 V, the cable rating had to rise with them, and 2,000 V DC PV wire became a standard product. That rating is marked along the jacket, and it is the first thing to establish on any solar reel, because a 1 kV cable cannot be used on a 1,500 V system no matter how good its condition.

Dual rating is the second distinction. USE-2 is an underground service entrance cable rated for direct burial and wet locations; RHW-2 is a rubber-insulated building wire rated for dry and wet locations and for higher temperatures. A cable marked USE-2/RHW-2 satisfies both, which is what allows one reel to run in a trench, in a conduit and in free air on a rack. Solar work specifies dual-rated cable precisely because the routing changes as a project is built.

Tray-rated multiconductor PV cable also exists for the DC and AC sides of commercial inverters. It is an assembly rather than a single conductor, and it is reviewed like any other tray cable, with the PV rating as an additional requirement rather than a substitute.

Solar in New York: community, rooftop and utility scale

New York's solar build-out has three shapes, and each produces a different cable lot. Community solar projects — the subscriber-funded arrays that were supported by the NY-Sun program — are typically ground-mounted in the North Country, the Mohawk Valley, the Southern Tier and the rural Hudson Valley, often on farmland, brownfields or closed landfills. They use long DC string runs, extensive USE-2/RHW-2 feeder cable and a medium voltage interconnection.

Rooftop and canopy projects in New York City, Long Island and Westchester use tray-rated and sunlight-resistant cable in shorter runs, with more conduit and more connector terminations. Utility-scale projects, concentrated in the same upstate counties as community solar but larger, use 1,500 V DC designs, 2 kV cable and large DC feeders, plus medium voltage collection cable to the substation.

Each of those leaves surplus differently. A rooftop contractor finishes with part reels of 10 and 8 AWG PV wire and boxes of connectors. A utility-scale project finishes with whole reels of 2 kV cable and large USE-2 feeders, usually with the reel tags retained because the owner's commissioning records required them.

What decides the value of a solar reel

The voltage rating comes first, because it decides which projects the cable can serve. Conductor size and length come next, then the insulation compound and the specific listings. A 2 kV, 10 AWG, tinned copper PV wire with a legible print is a stock item for any solar contractor; the same reel without a print cannot be verified and drops to metal value.

Condition is unusually decisive in this family. Sunlight ages cable, and aged cable shows it: the jacket chalks, then cracks, and the insulation underneath hardens until it will not strip cleanly or seal in a connector. Cable that has been in service on a rack for a decade is not reusable even if it still tests continuous. New surplus that never left the pallet is the opposite, and it is the material worth pursuing.

• DC voltage rating — 1 kV or 2 kV — from the jacket print
• Size, and whether the conductor is tinned
• Insulation compound and the UL listing: 4703, 854, 44
• Sunlight, ozone and direct-burial ratings where present
• Footage, reel condition and whether the cable has been outdoors in service