Current/OS Plenary at NMi: Progress in DC Standardization

NMi hosted the 6th Current/OS Plenary Session in Delft from January 27–29, welcoming industry leaders, manufacturers, and regulators to collaborate on advancing Direct Current (DC) standardisation and certification. With nearly 130 participants across 75+ member companies, discussions focused on developing certification schemes, technical specifications, and regulatory frameworks to support the growing adoption of DC technology across key sectors.

Progress on DC Standardization and Certification

The plenary marked an important milestone with the publication of System Reference Document (SRD) 2.0, providing a structured approach for DC implementation across infrastructure, energy systems, and applications. Technical subgroups continue refining product and testing specifications for essential DC components, including protection devices, metering, converters, installation rules, and cables. Establishing these technical foundations is critical to ensuring safety, interoperability, and regulatory alignment in DC systems.

Certification development remains a priority, with a scheme operator now in place and the first product certifications expected by end 2025/early 2026. EV charging stations and lighting systems have been identified as initial use cases, aligning certification requirements with industry needs and technical committee guidance.

Beyond standardisation, workforce training and education are expanding, led by Tallinn University, with initiatives such as online courses and webinars to support professionals entering the DC sector. In North America, efforts are underway to adapt existing standards (NEC, UL), assess regulatory requirements, and evaluate safety measures to support broader market adoption.

With DC microgrids projected to reach $20 billion by 2032, increasing integration of renewables, battery storage, and energy-efficient applications drives demand for standardised certification frameworks and testing procedures to ensure safe and scalable deployment.

NMi’s Role in DC Metrology and Certification

As a recognised Notified Body, NMi plays an important role in ensuring accurate, traceable, and reliable measurement solutions for DC systems. NMi contributed to discussions on certification methodologies, metering standardisation, and compliance frameworks at the plenary.

NMi is currently actively involved in two certification use cases:

• EV Charging Stations (EVCS) – Establishing testing and certification requirements for global EV charging infrastructure.
• Lighting Systems – In collaboration with Tridonic and the Certification Scheme Team, supporting metrology requirements for DC-powered lighting applications.