Title: System for the Analysis of Global Energy (SAGE): Electric Sector Enhancement
1System for the Analysis of Global Energy (SAGE)
Electric Sector Enhancement
John J. Conti Acting Director Office of
Integrated Analysis and Forecasting Prepared for
the Energy Technology System Analysis Program
(ETSAP) Florence, Italy November 24, 2004
2SAGE Background
- A MARKAL-based energy model utilizing the VEDA
software for model creation and results analysis. - Produces integrated energy projections through
2025 for 15 regions of the world. - EIAs International Energy Outlooks have been
based on SAGE model results since 2003. - Uses a time-stepped approach to address foresight
and other modeling issues (i.e., learning, market
sharing, etc). - Each year a number of model enhancements are
scheduled (some are even implemented). - One key improvement this year has been a
reformulated electric sector.
3Electricity Sector Enhancement
- Purpose to increase model flexibility in
choosing between alternative fuel/technology
combinations in response to various changes in
inputs to address alternative policies, energy
market conditions, or technological
characteristics. - Allow model to economically choose to build and
operate appropriate mix of electricity
technologies - Maintain selected external constraints to allow
for regional differences and assumed must run/out
of merit order generation and capacity selection
(e.g., renewable portfolio standards, etc.) - Allows for the appropriate economic valuation of
carbon allowances in electricity sector and
flexibility to react to carbon shadow prices or
constraints.
4Elements Modified
- Improved the technological characterization of
existing and new capacities. - Better representation of peaking, intermediate,
and baseload demand
5Concerns with Previous SAGE Electricity Model
Formulation
- Model builds and operates large amounts of
baseload technologies - Constraints required to force proportional
generation by other fuels - Model dispatch and capacity choice decision were
not based on the technological specifications,
capital cost parameters, and fuel costs
6Concerns with Previous Model Formulation (cont.)
- Annual electricity demand is segmented into 6
periods - Summer, Winter, and Intermediate
- Day and Night
- Electricity capacity expansion and dispatch
decisions meet demand varying by the above 6
seasonal/diurnal segmentations. - The 6 segment load demand curve representation is
too flat to adequately capture the comparative
economics of peaking and intermediate technologies
7New SAGE Electricity Model Formulation
- Changed seasonal/time of day framework to load
duration curve concept - Developed mapping of typical end use load for
each end use to aggregate load. - By region, selected dominant end use load as
basis for establishing time slots for load
duration curve slices (e.g., industrial worlds
peak dominated by cooling load) - Stayed within default 6 slice limit.
8New SAGE Electricity Model Formulation (continued)
- Demands mapped to load slice based on end use
demands proportion of load slice - Load slices are organized around load duration
curve
Peak time slice
Intermediate time slice
Demand met with Peaking capacity
Demand met with Intermediate
1st Slice First 2 of hours
2nd Slice Next 10 of hours
3rd Slice Next 22 of hours
4th Slice Next 22 of hours
5th Slice Next 22 of hours
6th Slice Next 22 of hours
Base load
8760
9Original vs. New SAGE Electricity Load Curves
10Model Results Summary
- Peaking facilities (such as turbines) are built
to operate in the 1st (i.e. peak) slice - Intermediate facilities (such as combined cycle)
are built to operate primarily in 2nd slice. - Baseload facilities (such as coal or combined
cycle) are built to operate in the four baseload
slices. - First, we will look at the capacity expansion
decision, followed by the dispatch decision.
This is based on the U.S. region for the year
2025.
11Electric Sector Capacity
12Electric Sector Capacity by Segment
13Comparison of Total Generation
14Generation by Segment
15Electricity Reformulation Benefits
- Appropriate model capacity expansion and dispatch
is not forced via additional constraints. - Improved model application for policy analysis
- Electricity price forecast more reasonable
- Electric sector results respond to changes in
endogenous variables such as relative fuel prices.
16Other SAGE Activities
- In progress
- Improved market share algorithm
- Enhanced discount, interest, investment hurdle
rate methodology - Formalized version control, issue tracking, and
software installation. - Planned
- Kyoto Scenario Analysis