Code Change Summary: A new informational note addresses bifacial PV modules.

In the 2023 NEC^®, minor editorial revisions were made in Section 690.8(A)(1) to align with several PV dc circuit terms that were deleted, and a new informational note provides insight into PV modules that can produce electricity when exposed to light on more than one surface (bifacial).

According to the new informational note, PV modules that can produce electricity when exposed to light on multiple surfaces are labeled with applicable short-circuit currents. Additional guidance is provided in the instructions included with the product listing.

Bifacial PV modules can produce power from both sides of the PV module. Traditional modules have an opaque backing sheet under the PV cells whereas bifacial modules can be frameless allowing exposure to the top and bottom of the PV module permitting significant gains in additional power produced by the module. This is beneficial for PV module installations (as in the image) where adjacent building surfaces are highly reflective.

PV modules capable of producing electricity when exposed to light on multiple surfaces may have higher short-circuit current ratings (ISC) than those with an ISC rating based only on front-side exposure.

Bifacial PV modules will be listed, and labeled with appropriate short-circuit current ratings as required in the product safety standard and the PV module instructions will provide guidance on determining the ISC rating in order to properly size conductors and overcurrent devices for the PV system dc circuits.

Below is a preview of the NEC^®. See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2023 NEC^® edition of NFPA 70.