IEEE Power & Energy Magazine - May/June 2014 - 28

NYISO
1.7 GW
MISO
14.2 GW

Other West
8.4 GW
CAISO
1.6 GW

SPP
4 GW

ERCOT
2.1 GW

ISO-NE
2.4 GW

PJM
31.3 GW

Southeast
14.2 GW

Legend
ISOs/RTOs
California ISO
ERCOT
Midcontinent ISO
ISO New England
New York ISO
PJM
SPP

figure 1. Potential coal retirements (map created with Ventyx, an ABB Company, Energy Velocity Suite, Intelligent Map).

to maintain voltage stability. how will the grid maintain steady state and dynamic voltage support?
✔ Demand management: Generation resources were
historically built to provide low-cost electricity and
ancillary services and capacity to meet reliability at
peak load. today, demand management can provide
these same services. What is the right mix and types
of programs and incentives that can maximize the
benefits of demand management?
✔ Maintaining grid resiliency with microgrids: natural disasters, such as hurricane sandy, have registered strongly in the minds of policy makers and have
motivated towns, cities, and electric utilities to provide greater operational resiliency for a wide range of
critical infrastructure and services. What is the role of
small microgrids in providing resiliency to the grid?
While there may be other trends driving the evolution of
the grid, the authors expect these ten trends to be at the heart
of the discussion in the coming years. the remainder of this
article is devoted to more in-depth discussions of each trend.

Coal Plant Retirements
coal plant owners face an important decision: should they
invest to comply with the proposed environmental regulations or retire their plants? the environmental Protection agency (ePa) has proposed a set of rules/standards to
reduce air and water pollution: the cross-state air Pollution
rule (csaPr), clean Water act section 316(b), and regulations around hazardous air pollutants such as mercury and
28

ieee power & energy magazine

air toxics standards, GhGs, and coal combustion residual
disposal. in august 2012, csaPr was vacated by the u.s.
court of appeals and has reverted back to previous requirements, the clean air interstate rule, until a valid version
of csaPr can be proposed and implemented. to continue
operating, ePa regulations will require coal plant owners to
retrofit their plants with environmental control technology or
retire the affected coal units altogether.
Based on the authors' estimates, 17 GW of coal capacity
was retired from 2010 through september 2013, and about
69 GW more is likely to retire or mothball through 2021 for
a total of ~86 GW of coal retirements. the majority of the
remaining coal capacity is likely to be retrofitted with technology, such as flue gas desulfurization and baghouses, for a
projected cost of approximately us$90 billion expended in
2013 and beyond. Figure 1 shows the projected coal retirement capacity by nerc subregion.
to maintain reliability levels, it is estimated that about
40-50 GW of new capacity will be needed in the united
states by 2020 to replace retirements, meet load growth,
and maintain reliability. the price of natural gas, the cost of
compliance, and the cost of gas-fired generation will affect
the rate and amount of coal generation retired. With nearterm gas prices around us$4/mmBtu, a high retirement scenario is being born out as reflected in the current estimates
of 86-GW total retirements.
the evolution of future ePa regulations is not known,
but as it stands, the power industry has opened the door
for new generation capacity. historically, drivers for new
may/june 2014

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - May/June 2014