Northern Power Systems has achieved UL 1741 SB certification for the power converter of its NPS 100C wind turbine as of February 3, 2026.
The certification marks an important milestone for the NPS 100C in the U.S. distributed wind market, demonstrating conformity with advanced grid-interconnection requirements associated with IEEE 1547-2018 and the IEEE 1547.1-2020 test procedures.
What Is UL 1741 SB Certification?
UL 1741 covers inverters, converters, controllers and interconnection system equipment used with distributed energy resources (DERs). Supplement SB addresses testing associated with the grid-support and interconnection requirements of IEEE 1547-2018, with testing based on IEEE 1547.1-2020 procedures.
For distributed energy projects, these requirements are important because modern DERs may be required to support the electric grid during voltage and frequency disturbances rather than simply disconnecting.
This is particularly relevant as distributed energy resources become a more active part of modern power systems. Advanced interconnection standards define how generating equipment should behave when grid voltage or frequency moves outside normal operating conditions. By testing these capabilities against recognized procedures, certification gives utilities, developers and other project stakeholders a consistent framework for evaluating grid-connected equipment.
For wind projects, this technical validation helps demonstrate that the turbine’s power conversion system has been tested for the grid-support functions addressed by the applicable certification requirements.
UL 1741 SB Certification and Distributed Wind
Meeting modern grid requirements presents specific technical challenges for distributed wind. Unlike solar PV, wind turbines must manage variable mechanical power input while delivering the electrical response required at the grid connection point.
The NPS 100C converter supports advanced grid functions including:
- Voltage and frequency ride-through
- Volt-VAR and Volt-Watt control
- Frequency-Watt response
- Standardized utility communication and control through SunSpec Modbus
These capabilities allow the NPS 100C to respond to grid conditions in accordance with applicable interconnection settings and requirements.
What the Certification Means for U.S. Wind Projects
For developers, utilities, asset owners and NPS partners, UL 1741 SB certification provides independently tested evidence that the NPS 100C converter can meet the advanced grid-support requirements covered by the certification.
This can be particularly relevant when evaluating equipment for distributed wind projects in U.S. jurisdictions that have adopted IEEE 1547-2018-based interconnection requirements.
For distributed wind developers, having certified equipment provides a clearer technical basis when evaluating a project against modern interconnection requirements. It can also help utilities and other project stakeholders assess the NPS 100C’s tested grid-support capabilities using recognized standards and procedures.
Interconnection requirements can vary by utility, jurisdiction and individual project. For this reason, equipment certification should be considered one part of the broader interconnection process, alongside project-specific engineering, utility requirements and applicable local rules.
Certification does not replace project-specific utility review or local interconnection requirements, but it provides developers and utilities with standardized evidence of the converter’s tested grid-support capabilities.
More Than 18 Months of R&D and Testing
The achievement follows more than 18 months of dedicated research, development and certification testing by Northern Power Systems.
The work required the development and validation of advanced converter controls designed to support the grid-response capabilities evaluated as part of the certification process.
The certification project was completed by Northern Power Systems’ U.S. subsidiary, with significant funding support from the National Laboratory of the Rockies (NLR; formerly NREL) through its Competitiveness Improvement Project (CIP), as well as technical and testing automation support from DER Security.
The certification strengthens the NPS 100C’s position as a grid-ready distributed wind solution for projects requiring advanced interconnection capabilities.
Planning a Grid-Connected Distributed Wind Project?
If you are evaluating distributed wind for a U.S. project, Northern Power Systems can help assess turbine configuration, grid requirements and project-specific considerations.