Appendix J. Models Used To Generate the IEO2008 Projections
World Energy Projections Plus (WEPS+)
The IEO2008 projections of world energy consumption and supply were generated
from EIAs World Energy Projections Plus (WEPS+) model. WEPS+ is a system
of sectoral energy models that provide a loosely linked, integrated equilibrium
modeling system. It is used primarily to provide alternative energy projections
based on different assumptions for GDP growth and fossil fuel prices. The
WEPS+ common platform allows the models to communicate with each other
and provides a comprehensive, central series of output reports for analysis.
For IEO2008, WEPS+ incorporates a separate transportation sector model
with an extensive level of detail for modes and vehicle types. WEPS+ also
incorporates some additional detail on industrial energy use in China and
India, additional detail on end-use electricity consumption, and an interface
to the System for the Analysis of Global Energy Markets/Global Electricity
Module (see below) for generation, capacity, and fuel consumption in the
electricity sector.
WEPS+ produces projections for 16 regions or countries of the world, including
North America (United States, Canada, and Mexico), OECD Europe, OECD Asia
(Japan, South Korea, and Australia/New Zealand), Russia, other non-OECD
Europe and Eurasia, China, India, other non-OECD Asia, Brazil, and other
Central and South America. Currently, the projections extend to 2030.
In some individual models, the detail also extends to the subsector level.
For each end-use sector, WEPS+ projects consumption of the key primary
energy sources: liquid fuels and other petroleum, natural gas, coal, nuclear
power, and hydroelectricity and other renewables. The model also provides
intermediate consumption projections for electricity in the end-use demand
sectors. The model projections generally are dependent on aggregate supply
prices, GDP levels, and population. Supply projections are also made for
the key supply sources corresponding to the primary consumption sources.
The modeling system accounts for projections of economic activity represented
by GDP, population, and world energy prices. Carbon dioxide emissions from
the combustion of fossil fuels are also calculated by region.
WEPS+ includes a detailed model of the worlds transportation sector, which
provides projections by four transport modes: road, rail, water, and air.
A variety of services are represented for each mode, such as light-duty
vehicles, two/three-wheel vehicles, heavy trucks, passenger rail, and freight
rail. WEPS+ separates service demand (e.g., road travel by cars, commercial
trucks, and heavy trucks) from vehicle efficiency and bases the projections
on economic growth (as measured by GDP) and fuel prices.
A more detailed representation of the industrial sectors in China and India
is incorporated into WEPS+. These projections are based on an econometric
estimation of historical consumption patterns at a nine-industry level
of detail. End-use electricity consumption was analyzed in detail across
several sectors and for the major electricity-consuming regions, and a
module incorporating the analysis was included in WEPS+.
Although the modeling was extended in several areas of WEPS+, in the remaining
core sections WEPS+ is a microeconomic model, used primarily to provide
alternative energy projections under different assumptions about GDP growth
and fossil fuel prices. It serves as a repository for reference case output
generated from complex models that focus on specific supply or demand series.
The reference case reflects output from those models and incorporates analysts
judgment on the potential for demand by end-use sector and fuel type on
a regional basis. After the reference case is established, WEPS+ is used
to calculate coefficients for the response surface, which are saved in
a database. The reference case output tables reflect the same information
that is embedded in the input tables. Alternative cases reflect different
assumptions about future economic growth and energy prices. When an alternative
case is run, the model uses the previously calculated coefficients to produce
new projections relative to changes in GDP and energy prices and produces
output tables that reflect the changes.
System for the Analysis of Global Energy Markets/Global Electricity Module
(SAGE/GEM)
SAGE/GEM is a regional model that provides a technology-rich basis for
estimating regional electricity consumption. For each region, SAGE/GEM
inputs reference case estimates of electricity demand (e.g., commercial,
industrial, residential, and transportation) that were developed on the
basis of economic and demographic projections in WEPS+. Projections of
electricity generation in SAGE/GEM to meet the electricity demands are
estimated on the basis of each regions existing electricity use patterns
(load shape), the existing stock of electricity generation equipment, the
characteristics of available new electricity generation technologies, and
fuel supply (prices and production).
Period-by-period market simulations aim to provide each regions electricity
generation services at minimum cost. Nine load slices are modeled (summer,
winter, and intermediate seasons for base, intermediate, and peak loads).
SAGE/GEM also allows energy commodities to be traded between regions. Inventories
of existing generation technologies by plant type and region are derived
from Platts UDI World Electric Power Plants Database.24 Generation and
consumption for historical years are calibrated with historical data from
EIA and the International Energy Agency. Resource availability for fossil
fuels is provided by WEPS+ and translated into supply curves for use in
SAGE/GEM, taking into consideration fuel consumed in non-electricity sectors.
Renewable resource availability is derived from analyst reviews of regional
data.
SAGE/GEM is a simplified subset of the SAGE modeling system. A full description
of the SAGE model is available in a two-volume set. The first volume provides
a general understanding of the models design, theoretical basis, necessary
user-defined assumptions, and output. It also lists the software necessary
to develop and analyze the results of SAGE-based policy and energy market
scenarios. In addition, Volume I includes a Reference Guide, which explains
each equation in detail. The second volume serves as a Users Guide for
those actively developing SAGE-based scenario analyses. The documentation
is available on EIAs web site in the model documentation section of Current Publications (www.eia.doe.gov/bookshelf/docs.html).
SAGE documentation is also available as part of the documentation for the
MARKAL family of models (www.etsap.org/ MRKLDOC-III_SAGE.pdf).
Generate World Oil Balance Model (GWOB)
The projections for world liquids production in IEO2008 reflect an assessment
of world oil supplybased on current production capacity, planned future
additions to capacity, resource data, geopolitical constraints, and pricesthat
is used to generate conventional crude oil production cases. The scenarios
(price cases) are developed through an iterative process of examining demand
levels at given prices and considering the price and income sensitivity
on both the demand and supply sides of the equation. Projections of conventional
liquids production for 2008 through 2015 are based on analysis of investment
and development trends around the globe. Data from EIAs Short-Term Energy
Outlook are integrated to ensure consistency between short- and long-term
modeling efforts. Projections of unconventional liquids production are
based on exogenous analysis.
Nine major streams of liquids production are tracked on a volume basis:
(1) crude oil and lease condensate, (2) natural gas plant liquids, (3)
refinery gains, (4) Canadian oil sands, (5) extra-heavy oils, (6) coal-to-liquids,
(7) gas-to-liquids, (8) shale oils, and (9) biofuels (tracked on both a
volume basis and an oil equivalent basis). Biofuels are reported in terms
of barrels of oil equivalent, unless otherwise stated.
Notes and Sources |