Try out the E4ST Fast Predictor!


The Engineering, Economic, and Environmental Electricity Simulation Tool (E4ST) was developed by researchers at Cornell and Arizona State Universities, at Rensselaer Polytechnic Institute, and at Resources for the Future, with support from the U. S. Department of Energy’s CERTS program as well as the Power Systems Engineering Research Center and the New York Independent System Operator.

E4ST is available openly, without charge. It consists of a set of software toolboxes that can be used to estimate present and future operating and investment states of an electric power system, including generator dispatches, generator entry and retirement, locational prices, fixed and fuel costs, air emissions, and environmental damages. The E4ST software toolboxes can be used with suitable data from any part of the world.

E4ST can be applied to detailed system models. Algorithms are included that simulate the economic operation of the power grid, in response to the model-user’s projections of economic factors (e.g. fuel prices), government incentives or environmental regulations. Simultaneously, the algorithms project and implement the economical investment and retirement of generation over time, by location. The algorithms are designed to maintain the redundancy necessary for service reliability.

E4ST is useful for both energy- and environmental-policy planning purposes. It accounts for short- and long-term feedbacks between energy and environmental policies. It can be used to project the operation and evolution of the power system under any combination of prices, demand patterns, and policies specified by the user. It can calculate the net benefits of any policy simulated, and disaggregate them into the benefits or costs for customers, generation owners, the system operator, the government, public health, and the environment.

In addition, E4ST can be used as a transmission planning tool to explore the consequences of network changes. The existing electric transmission system is fixed throughout these simulations, and only the generator dispatches and customer loads respond endogenously, but the user can change the transmission network and re-run the simulation to calculate the effects of the change, potentially repeating this thousands of times to test many different transmission system investment scenarios.

This website includes a complete three-bus model ready for use with E4ST. It also includes the developers’ detailed US generator data and the developers’ other publicly releasable input data, which can be used in conjunction with a transmission model provided by the user.