U.S. Department of Energy - Energy Efficiency and Renewable Energy

Distributed Energy Program

UL 1741

Underwriters Laboratories is a nonprofit, independent organization that develops standards for product safety and conducts testing activities based on its own and other test procedures. One of these standards is UL 1741.

First released in May 1999 under the title "Standard for Static Inverters and Charge Controllers for Use in Photovoltaic Power Systems," UL 1741 is being updated under its latest version, "Standard for Inverters, Converters, and Controllers for Use in Independent Power Systems" to include requirements that apply to the more broadly defined distributed power sources incorporated under IEEE 1547. UL 1741 will combine product safety requirements with the utility interconnection requirements developed in the IEEE 1547 standard to provide a testing standard to evaluate and certify distributed generation products.

The following documents are available as Adobe Acrobat PDFs. Download Acrobat Reader

The following documents summarize work to update UL 1741. Explore them to learn what has been accomplished.

Underwriters Laboratories: Streamlining Interconnection (PDF 271 KB). NREL/FS-560-35051. Golden, CO: National Renewable Energy Laboratory. October 2003. A fact sheet summarizing collaborative work with Distribution and Interconnection R&D.
Development of a UL Standard for the Utility Interconnection of DG Products (PDF 480 KB). Presented at the Electric Distribution Transformation Annual Program and Peer Review Meeting, 2004, in Coronado, CA.
Development of a UL Standard for the Interconnection of Distributed Generation (PDF 159 KB). Presented at the Distribution and Interconnection R&D Annual Review, 2003, in Arlington, VA.
Development of a UL Standard for the Interconnection of Distributed Generation (PDF 1.9 MB). Presented at the Distributed Power Program Quarterly Review, July 2002, in Madison, WI.
Development of a UL Standard for the Interconnection of Distributed Generation (PDF 2.8 MB). Presented at the Distributed Power Program Annual Review, 2002, in Arlington, VA.
Development of a UL Standard for Distributed Generation (PDF 219 KB). Presented at the Distributed Power Program Quarterly Review, October 2001, in Golden, CO.
Development of a UL Standard for the Interconnection of Distributed Generation (PDF 385 KB). Presented at the Distributed Power Program Quarterly Review, July 2001, in Washington D.C.