World Energy Projection System Plus Model Documentation: Electricity Module
February 13, 2017
Introduction
Purpose of this report
The World Electricity Model (WEM) of the World Energy Projection System Plus (WEPS+) is a computerbased
energy transformation model of the world electricity generation sector. This report describes the
version of WEM that was used to produce the electricity generation projections published in the
International Energy Outlook 2016 (IEO2016). The WEPS+ is a modular system, consisting of separate
energy models that are joined together through the overall system model in order to communicate and
work with each other. These models are developed independently but are designed with well-defined
protocols for system communication and interactivity. The WEPS+ modeling system uses a common and
shared database (the “restart” file) that allows all the models to communicate with each other when
they are run in sequence over multiple iterations. The system uses an iterative solution technique that allows for convergence of consumption and price to a simultaneous equilibrium solution.
This report documents the objectives, analytical approach, and development of the World Electricity Model. It also catalogues and describes critical assumptions, computational methodology, parameter estimation techniques, and model source code. This document serves three purposes. First, it is a reference document providing a detailed description for model analysts, users, and the public. Second, it meets the legal requirement of the U.S. Energy Information Administration (EIA) to provide adequate documentation in support of its models (Public Law 93-275, section 57.b.1). Third, it facilitates continuity in model development by providing documentation from which energy analysts can undertake and analyze their own model enhancements, data updates, and parameter refinements for future projects.
Model summary
WEM projects the amount of electricity generated to satisfy the electricity demands of the end-use
demand models. Specifically, WEM projects the consumption of fossil, renewable, and nuclear fuels or
fuel equivalents for the generation of electricity, based on both policy and least cost. The model projects
annual electricity generation and electric power generating capacity, by technology, for 13 energy
sources in each of the 16 international regions, through 2035. In addition, it projects end-use electricity
prices for each of four demand sectors, by region.
WEM is a technology-based, least-cost model that uses a logit function to estimate levelized cost for new generation technology in three load segments. It then uses the levelized costs to project market shares for each technology. The model accounts for a slate of available new technologies along with their corresponding characteristics. These technology characteristics vary by region and include heat rates (efficiency), capital cost (per kilowatthour), fixed operating cost, variable operating cost, availability factor, and more. For each fuel type, the model features different technology representations, including carbon capture and storage (CCS) technologies.
The WEPS+ restart file provides WEM with macroeconomic, consumption, and price projections. These projections are determined beforehand by the Global Activity Model and the demand and supply models. Outputs from WEM include projections of the amounts of fuel consumed for electricity generation (by fuel), of electricity generation, and of electricity retail prices (by sector). These outputs are exported to the restart file for use by the other WEPS+ models.
Model archival citation
This documentation refers to the WEPS+ World Electricity Model, as archived for the International
Energy Outlook 2016 (IEO2016).
Model contact
Augustine Kwon
U.S. Energy Information Administration
U.S. Department of Energy
1000 Independence Avenue, SW
Washington, D.C. 20585
Telephone: (202) 586-3645
E-mail: augustine.kwon@eia.gov