EPRI: Electric Power Research Institute

Smart Grid Resource Center

Simulation Tool – OpenDSS

The OpenDSS is a comprehensive electrical power system simulation tool primarly for electric utility power distribution systems. It supports nearly all frequency domain (sinusoidal steady‐state) analyses commonly performed on electric utility power distribution systems. In addition, it supports many new types of analyses that are designed to meet future needs related to smart grid, grid modernization, and renewable energy research. The OpenDSS tool has been used since 1997 in support of various research and consulting projects requiring distribution system analysis. Many of the features found in the program were originally intended to support the analysis of distributed generation interconnected to utility distribution systems and that continues to be a common use. Other features support analysis of such things as energy efficiency in power delivery and harmonic current flow. The OpenDSS is designed to be indefinitely expandable so that it can be easily modified to meet future needs.

OpenDSS Download Files 

This is the main site for obtaining the release versions of the program. You can also get to other parts for the OpenDSS site by following the menu items. Note that release versions are posted irregularly every 3-4 months. If you want to keep up with the latest additions to the program you can either build from the source code or obtain the latest beta build from the Code repository: 

32-Bit Version 
64-Bit Version

While the newer versions have the more up-to-date features and bug fixes such as those described in the latest Tech Notes  in the Wiki or in the Discussion Forum, they could be less tested.

OpenDSS Open Discussion Forum 

This is an open forum on the Sourceforge.net site on which users post questions and discuss answers. There is a lot of information available here, especially for new users. Note that you must acquire a Sourceforge.net ID to post a message. No ID is required to simply view the forum.


The user manual and various documentation files may be found in the Doc folder in the Distrib folder of the main repository.

Top Level of Main Repository 

This link will take you to the source code repository. You may download individual files from here. If you want to keep up with the latest source code, a SVN client such as TortoiseSVN is recommended. For instructions on one way to do this, see this page in the Discussion Forum.


This is a direct link to the Examples folder where users can find examples of using OpenDSS via several tools such as Excel and Matlab. The Scripts folder contains several examples of how to do various analyses and simulations. The Loadshapes folder contains several examples of yearly loadshapes along with the scripts for loading them.

IEEE Test Cases 

Many of the IEEE Test Feeders have been implemented in OpenDSS. This link will take you to the location in the repository containing the folders in which the OpenDSS script files are stored.

EPRI Test Circuits 

EPRI has released some of its distribution feeder library to the public. These are based on real US utility distribution feeders. The OpenDSS models are typically set up to do annual simulations.

Source Code 

A direct link to the location in the repository where the source code files are kept. You can also get here by going to the top level of the repository and selecting the Source folder.

Top level of Distribution Area (Betas, Docs, Examples) 

Various files in the release and beta distributions.