IEEE Power & Energy Magazine - November/December 2014 - 83

requires active management of gas-electric interdependencies
to ensure bulk power reliability, security of supply, and the
quick activation of mitigation measures by PPas and pipeline
operators when gas- or electric-side contingencies occur.
the shale gas phenomenon, stringent environmental
regulations, and the resultant economic pressures on the
nation's fleet of coal-fired generators have heightened the
PPas' dependence on pipeline infrastructure across the
eastern interconnection. Many gigawatts of coal-fired
capacity are expected to be retired over the next several
years. in our opinion, the eastern interconnection region's
increased dependence on natural gas for electric generation raises complex but solvable challenges associated with
the management of pipeline and storage infrastructure to
keep pace with the coincident demand requirements of
gas utility loads and power generation loads. these problems show up throughout the heating season (november
through March) but are also evident in some parts of the
study region during the peak cooling season as well. the
substantial increase in the use of gas for power generation
has challenged the ability of the gas delivery system to
meet the simultaneous demands of rci customers and the
expanding fleet of efficient, gas-fired generation plants during periods of high demand.

Modeling Framework
completion of the study required extensive modeling of the
gas and electric systems, particularly for targets 2, 3, and 4.
Four different commercially available modeling systems were
used, as illustrated in Figure 3, which shows key inputs, outputs, and data transfers among models. aUroraxmp is a
comprehensive electricity market modeling software program
used by many stakeholders and electric planners throughout
north america. the core of the program is a fast hourly dispatch algorithm that simulates the economic commitment and
dispatch of power plants in a chronological, multizone, transmission-constrained system. the aUroraxmp model is well
suited to the purposes of this study for two reasons. First, it is
relatively easy to reconfigure the model's data structures so as
to incorporate the numerous varying input assumptions within
the different control areas of the six PPas. second, it executes
quickly enough to be practical for performing and validating
multiple scenario runs for the large study region.
the gas Pipeline competition Model (now called simply
gPcM) is a modeling product that represents the integrated
natural gas market in north america and is used by Lai to
simulate the flow of natural gas across the pipeline and storage
infrastructure from producing areas to market areas throughout the study region. gPcM uses a node-arc network. nodes

Compressor
Station
Interconnecting
Pipeline

Merchant
Plant

Compressor Station
Meter Station

LDC Load
Compressor
Station

LDC Load

Merchant
Plant

LDC Load
Compressor
Station

Compressor
Station

Merchant
Plant

Compressor
Station
Merchant
Plant

Proposed
Pipeline
Compressor
Station
Merchant
Plant

Pipeline

figure 4. A sample schematic for the gas pipeline infrastructure model.
november/december 2014

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Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - November/December 2014