The use of solar photovoltaics (solar PV) provides an alternative means of energy production that is clean and sustainable. The efficiency of solar PV devices depends on the quality of the wiring used in the installation. This article describes the solar PV wires that are commonly used in commercial solar wiring.
Solid or Stranded Wires for Solar PV
Wires can either be stranded or solid. Stranded wires consist of many thin, long strands of metal stranded together so that the wire looks like it is braided. Solid wires are long strands of solid metal.
Stranded wires are more flexible than solid wires, and there is reduced risk of corrosion and breakage with stranded wires. Stranded wires carry the current on the surface of the wires, and this makes them more efficient.
Metal Wires for Solar PV
Metal wires, like copper and aluminum, are good conductors of electricity, and these types of wires are generally used in commercial solar wiring. Copper is better than aluminum at conducting electricity, so it carries more current than aluminum at the same size. Copper is more expensive.
When energy efficiency is the primary consideration, copper wires are usually installed. When it comes to solar PV, aluminum wiring is used only for underground or overhead installation.
Insulation of Solar PV Wire
The insulation that covers the wire protects it from moisture, heat, ultraviolet light and chemicals.
- THW, THWN and TW can be used indoor or outdoor. Used in conduit for wet outdoor applications.
- THHN is a heat-resistant thermoplastic wire used in dry indoor locations.
- PV, USE-2 and RHW-2 can be used outdoors and in wet applications if the outer cabling is moisture and UV resistant.
- UF and USE can be used for moist or underground applications.
Specific color codes are used in solar PV installations to specify the function of each wire. Selecting the right PV wire for your commercial solar wiring can greatly improve efficiency.