Draft for Public Consultation: Code of Practice for Electrical Energy Storage Systems, 4th Edition

November 3, 2026

This code of practice looks at electrical energy storage systems (EESS) applications and provides information for practitioners to safely and effectively specify, design, install, commission, operate and maintain a system.

It covers electrochemical energy storage systems in electrical installations, integration into low-voltage power systems (AC and DC) and systems aligned with existing standards, regulations and guidance. Its scope includes EESS intended for individual dwellings, commercial applications, including multi-occupancy buildings and multi-occupancy residential buildings, and industrial applications.

This fourth edition looks to bring the code of practice up to date with the latest developments in the electrical energy storage market and ensure alignment with Amendment 4 of BS 7671.

Additions to the fourth edition include:

Updated guidance and reference to other related standards.
New guidance on islanding equipment.
Expanded battery technology coverage including sodium-ion batteries.
New guidance for values of consumer earth electrode resistance.
Enhanced guidance on arc flash, fire safety, RCD selection, earthing, signage and certification.

Deadline for comments: 9am on Monday 16 November 2026.

Download the Code of Practice for Electrical Energy Storage Systems, 4th Edition and the DPC comments form here.

electrical.theiet.org