How Standards Harmonization Is Making Energy Storage Easier to Permit and Inspect

Article 706 on energy storage systems didn’t undergo sweeping changes in the 2026 NEC, but what did shift is worth noting, especially for anyone who has found the permitting and inspection side of ESS work frustrating.

Rebekah Hren of Solar Tech Collective walks through three developments that are working together to make things clearer.

First, the 2026 code draws a much cleaner line between what belongs in Article 480, which covers stationary batteries, and what belongs in Article 706. 

Second, UL 9540, the safety certification standard for energy storage systems, has gone through significant revisions. The result is a certification that AHJs can trust to cover the key safety requirements. That means the NEC doesn’t need to carry a long list of requirements, because they are already handled by the standard. 

Third, NFPA 855: Standard for the Installation of Stationary Energy Storage Systems, now carries many of the installation requirements that used to live in the electrical code, things like capacity limitations and spacing requirements relative to doors, windows, and other equipment.

Taken together, Rebekah sees these developments as a meaningful step toward a more harmonized set of standards, one that should reduce confusion for inspectors and AHJs who have often had difficulty navigating a fast-moving technology landscape. She also serves on the UL Technical Committee for 9540, so she has a direct view into how that alignment is being maintained across standards.

Rebekah and her Solar Tech Collective colleagues cover Article 706 and much more in Comprehensive 2026 NEC Requirements for Electrotech: PV, ESS, EVs, PCS, and More, available now on HeatSpring. Enroll your team here!

Transcript below.

Brit: Article 706 on energy storage systems: what are the most consequential changes in the 2026 code for someone designing or permitting residential or commercial ESS?

Rebekah: So it’s pretty interesting. Article 706 didn’t change a whole lot in the 2026 code, but one thing that did happen is it got a lot more clear what belongs in Article 480, Stationary Batteries, and what belongs in Article 706, energy storage systems.

Along with that, the industry has really come a long way on two related fronts. One is UL 9540, the safety certification for energy storage systems, which has gone through a number of revisions lately. I think that’s going to make things easier for installers and AHJs, because they can trust that the safety certification is going to cover the requirements for energy storage systems. That means the code doesn’t have to carry a whole laundry list of requirements, because they’ll be covered in the certification. You lean on the certification and avoid the kind of field evaluations that might otherwise be required.

We also have NFPA 855, the installation standard for energy storage systems. A lot of the requirements around capacity limitations and spacing, things like how far systems have to be from doors and windows or from each other, are no longer in the electrical code. The electrical code still has important requirements, but we can lean on the installation standard and the safety certification.

The language is harmonized, the requirements are harmonized, and I think that’s going to make things easier, especially for inspectors and AHJs who have been navigating a lot of new technology coming into the market. I’m a member of the UL Technical Committee for 9540, so I get to watch a lot of this go back and forth and help make sure the code and the safety standard aren’t stepping on each other. I’m pretty hopeful that we’ve got things well harmonized at this point.