IEEE Power & Energy Magazine - November/December 2019 - 72

While natural gas-combustion turbines provide fast and accurate
ramping control and great amounts of operational flexibility, they
offer little in the form of fuel-assurance capability.
among renewable generation sources, which show distinct
patterns in resource quality across the continent (Figure 4).
Integration across sectors is becoming increasingly important since demand-side resources will be crucial to achieve
renewable integration and decarbonization goals. Of particular
importance are the transportation and building sectors. Not all
buildings will generate sufficient energy onsite, so communityor region-level renewable energy projects will develop to meet
these needs. The overall result will be a system of both centralized and distributed energy resources, some of which will
contribute to supply-side variability, complemented by flexible
end use in smart homes and buildings. Transportation-sector
integration is developing through pilot studies on smart EV
charging rates and test beds as well as testing mechanisms and
incentives to access inherent flexibility in EV charging.
Integrating the building sector through demand-side management has been on the horizon for many years and started
in California in 2007 with demand-response pilot programs.
Although its implementation has been slow, the majority of the
U.S. population has advanced metering, and new time-of-use
rate and demand-response pilot programs are being developed

in many states. While there is immense operational flexibility
potential on the demand side, its growth depends on the ability to engage consumers across all segments and develop data
architectures that can ensure data security and privacy.

Linking Various Sectors
Electricity and Gas: Flexibility and
Gas-Electric Coordination in PJM
Natural gas-combined cycle generators are well positioned
to meet the increasing needs for operational flexibility, as
coal, nuclear, and some combustion turbines offer limited or
no load-following capability. PJM Interconnection (located
in the eastern and midwestern United States) installed
capacity from natural gas generation is on track to increase
by more than 50% between the 2007/2008 and 2021/2022
delivery years, which extend from 1 June to 31 May (Figure 5). This has been largely driven by gas production from
the Marcellus and Utica shale reserves, both of which are in
the PJM footprint. Meanwhile, installed capacity from coal
and nuclear generation that has cleared in the PJM capacity

WI-EI Seam

ERCOT Seam

Pacific
12:00 p.m.

Mountain
1:00 p.m.

Central
2:00 p.m.

Population Center
Hydroelectric Power
Fossil Resources
Wind Resources
Solar Resources
Wind and Solar Resources

Eastern
3:00 p.m.

figure 4. A resource-quality and potential HV transmission expansion to support VRE integration across the United
States. ERCOT: Electric Reliability Council of Texas; WI-EI: western interconnection-eastern interconnection. (Source:
NREL Interconnections Seams Study; used with permission.)
72

ieee power & energy magazine

november/december 2019

IEEE Power & Energy Magazine - November/December 2019

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - November/December 2019