IEEE Power & Energy Magazine - July/August 2018 - 60

Fossil Fuel CO2 Emissions
(Million Metric Tons)

450
400
350
300 Historical GHG
2030 GHG
Emissions
250
Target
200
150
California
100
2050 GHG
Northeast (NE + NY)
50
Target
0
1990 2000 2010 2020 2030 2040 2050
Year

figure 1. In-state fossil-fuel CO2 emissions in California
and the U.S. Northeast, historical trends, and future goals.

help to both lower retail electricity costs and to mitigate grid
integration challenges relative to a low electrification future.
We also identify three key challenges warranting further
research: 1) accelerating customer adoption of building and
transportation electrification, which is lagging the pace needed
to achieve stated targets; 2) reforming electricity market design, especially to ensure long-term resource adequacy; and
3) managing distribution-level grid impacts, including larger
instantaneous loads, multidirectional flows, and increased
voltage fluctuations.
this article first describes the sectoral emissions landscape in both regions. then we describe the study methods
for both areas and results for California and the northeast
region, respectively. finally, we conclude with a discussion
of findings and areas for further research.

A Comparison of U.S. Northeast
and California Emissions
ghg emissions from fossil fuel combustion in the seven-state
u.s. northeast region and California are of a similar magnitude. according to the u.s. energy information administration (eia), 1990 Co2 emissions from fossil fuel combustion
(excluding imported electricity) were 382 million metric
tons Co2 (mmtCo2) in the northeast and 364 mmtCo2
in California. for consistency across states and regions, emissions data are based on the u.s. eia's state carbon dioxide
emissions data, which excludes emissions associated with
imported electricity as well as non-fossil fuel combustion Co2
and other ghgs.
fossil fuel emissions in both regions peaked around 2004.
in the northeast, by 2015, annual Co2 emissions had fallen
by approximately 16% from 1990 levels, driven mainly by
a shift away from coal- and petroleum-fueled electricity
to natural gas-fired generation. reduced production from
heavy, energy-intensive industries and ee investment played
a role as well.
California's fossil fuel emissions have fallen less dramatically and are now approximately equal to 1990 levels. the state's
60

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emissions reductions have not been as rapid as the northeast's
over the past decade in part because it relied less to begin with
on coal- and petroleum-fueled generation and, as a result, has not
benefited as much from the trend toward natural gas generation.
the 80 × 50 target implies an annual 2050 fossil fuel
emissions budget of 77 mmtCo2 in the northeast and 73
mmtCo2 in California, assuming commensurate reductions in non-fossil fuel ghg emissions (such as methane and
fluorinated gases) are achieved (figure 1). in the California
analysis, deeper than 80% reductions in fossil fuel emissions
are modeled, achieving 50 mmtCo2 by 2050 (an 87% reduction from 1990 levels). deeper reductions in the energy sector
are modeled due to anticipated limitations on the mitigation
potential for methane and other agricultural ghg emissions.
meeting these goals will require a step change in the
pace of emissions reductions in both regions. in California,
the pace of ghg reductions needed to meet the 2030 ghg
goal is even faster than the already ambitious rate of change
required in the northeast, requiring a more ambitious suite
of emissions reduction measures.

Emissions by Sector and the Need for
Transportation and Building Electrification
in both the northeast and California, the electric power sector is broadly on track for meeting 80 × 50 goals, but the
transport and heat sectors are not. transportation emissions
are the largest single component in both regions, exceeding
42% of emissions in both new york and new england and
representing 37% of California's total emissions. moreover,
transportation emissions are higher today than in 1990 in
both regions.
in the northeast, buildings are the second largest source
of direct ghg emissions, representing over 30% of total
ghg emissions. ee programs and fuel conversions from oil
to natural gas have reduced heating ghg emissions from
buildings by 12% from 1990 levels. still, delivered fuels
(mainly oil) retain a 30% market share. in contrast, direct
ghg emissions from buildings in California represent only
about 9% of total emissions, due to the milder climate and
higher reliance (over 90%) on natural gas heat. figure 2 compares in-state Co2 emissions from fossil fuel combustion, by
sector, for both regions.
given this current landscape, transportation electrification
is widely viewed as a central decarbonization strategy in both
regions. in the northeast, support for building electrification
is growing due to the region's high reliance on heating oil
and higher share of emissions from buildings. in California,
building electrification has not been policy priority to date, as
buildings represent a much smaller share of total emissions
and because the prevalence of low-cost natural gas for heating
presents greater economic hurdles to switching.

Methods
this section describes the analytical methods and scenarios
applied in both regions.
july/august 2018

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - July/August 2018