E4 Simulation Tool (E4ST)

Simulation Tool

The E4 Simulation Tool (E4ST) software can be used to predict or optimize operation, investment, and retirement of generators under different policy, price, demand, and transmission investment circumstances. It can calculate the total costs and benefits, and can disaggregate them into those for customers, generators, system operators, the government, the public’s health, and the global climate. The software is based on MATPOWER, giving it access to multiple state-of-the art free and commercial solvers, and is distributed as open-source under the standard 3-clause BSD license.

The problem is structured as a set of DC optimal power flow sub-problems, one for each of a set of representative hours used to model the range of operating conditions encountered over the course of the planning horizon. The costs of each of the DC OPF sub-problems are weighted by the relative frequency of the corresponding representative hour and can include, in addition to fuel costs, various types of environmental costs, from permit costs for emissions of specific pollutants to aggregate damages from fine particulates. The sub-problems are then linked together into one large optimization problem by generator capacity constraints and costs. These linking costs include capital costs of existing generation as well as investment in capacity.

Users can access the interface of the E4ST by standard Matlab-style commands. For details, see the Usage section in the documentation that is bundled with the code in the downloadable files. Developers can add policies to the input data sets or develop additional features by creating subclasses that inherit from the included interface classes. The design separates the code and the input and output data into the root folder and subfolders named InputData and OutputData, respectively. It also includes a test class to allow the developer to test each class and function hour by hour.

Complete 3-Bus Model

The download below also contains a ready-to-use 3-bus model that contains all of the types of input data. Though E4ST can simulate models with thousands of buses, this user-modifiable 3-bus model is sufficient for testing the various features of E4ST.

Getting Started

To be able to run your own simulations using E4ST, you will need the following:

System Requirements:

  • MATLAB R2013b or later
  • MATPOWER version 5.1 or later
  • the E4ST code, available as a ZIP file under Download below

It is also highly recommended that you install a high-performance LP/QP solver supported by MATPOWER such as Gurobi, CPLEX, MOSEK, Matlab’s Optimization Toolbox or GLPK, described in the Appendix of the MATPOWER User’s Manual.

Steps to install E4ST:

  1. Download and extract the E4ST zip file with the E4ST code and 3-bus model example model, linked in the Download section below.
  2. Unzip the downloaded file.
  3. Follow the instructions in the Installation section of the E4ST User’s Manual, included in the docs subdirectory.


We request that those using the generator data or toolbox for their research please cite the following references:

Daniel L. Shawhan, John T. Taber, Di Shi, Ray D. Zimmerman, Jubo Yan, Charles M. Marquet, Yingying Qi, Biao Mao, Richard E. Schuler, William D. Schulze, and Daniel J. Tylavsky, “Does a Detailed Model of the Electricity Grid Matter? Estimating the Impacts of the Regional Greenhouse Gas Initiative,” Resource and Energy Economics, Volume 36 Issue 1, January 2014, pp. 191–207. http://dx.doi.org/10.1016/j.reseneeco.2013.11.015.

Biao Mao, Daniel Shawhan, Ray Zimmerman, Jubo Yan, Yujia Zhu, William Schulze, Richard Schuler, Daniel Tylavsky. “The Engineering, Economic and Environmental Electricity Simulation Tool (E4ST): Description and an Illustration of its Capability and Use as a Planning/Policy Analysis Tool.” Proceedings of the 49th Annual Hawaii International Conference on System Sciences, Computer Society Press, forthcoming January 2016. (peer review information at http://www.hicss.org/components.htm)
DOI: (forthcoming)