IEEE Power & Energy Magazine - July/August 2018 - 61

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.

to simulate the impact of ghg reduction strategies on California's electric sector and energy infrastructure needs,
energy and environmental economics, inc. (e3) used the
California PathWays model. the model is an economywide, scenario-based energy technology model representing
California's energy system. this model incorporates information about the lifetime and rate of turnover of ghg-emitting equipment and technologies (e.g., buildings, vehicles,
water heaters, and light bulbs), allowing users to specify the
rates of sales of new equipment, the re buildout, and other
electric sector assumptions, as well as biofuel use, other ee
improvements, and changes in noncombustion ghg emissions. the model calculates total economy-wide ghg emissions, energy supply and demand, incremental capital costs
associated with the sale of new technology and equipment,
and fuel costs associated with each scenario.
using this tool, we estimate the hourly electricity demand for
each year between 2017 and 2050, reflecting changes over time
to end-use energy demands due to economic and population
growth, ee, and electrification. dispatchable electric generation
is dispatched against the hourly electric loads net of renewable
generation, allowing the model to calculate hours of renewable
overgeneration (i.e., when renewable supply exceeds demand in
any given hour). renewable integration solutions, such as flexible eV charging, energy storage, and flexible loads in buildings, are added to the scenario to reduce renewable curtailment.
California's electric system is modeled as a single zone, with
import and export constraints imposed at the borders.
the annual electricity demands, broken out by sector and
major end-use category [e.g., light-duty vehicle (ldV) electrification and building electrification] were then fed into a
second electric-sector-only model as a check on the electricity
dispatch results and to evaluate optimal electric sector capacity
expansion and renewable integration solutions. this electricsector model, resolVe, minimizes total electric sector capital expenditures and fuel costs in California over the planning
horizon, subject to an electric sector ghg constraint. the electric sector ghg constraint is derived from the economy-wide
pathways scenario, creating a set of assumptions for the electric sector that are internally consistent with meeting the state's
economy-wide ghg reduction targets in 2030 and 2050.

Northeast Methodology
the northeast study, carried out by national grid and siemens Power technology international, used iterative aurojuly/august 2018

raXmP and gas Pipeline Competition model (gPCm) simulations to simulate investment and operational impacts across
the region. auroraXmP is an electricity dispatch and capacity expansion model of the electric grid. gPCm is a model
that incorporates natural gas supply, demand, and infrastructure inputs, including pipelines, to solve for expected prices
and flows throughout north america.
electrification load forecasts were developed exogenously
from the simulation based on projections of end-use performance and stock turnover of key technologies. the study
team created hourly, temperature-dependent, heating load
shapes based on the most up-to-date available data, including a 2016 massachusetts and rhode island study that generated field-validated, air-source heat pump operating data.
hourly ldV electrification load shapes were likewise based
on field-validated data from the u.s. department of energy
"eV Project" from 2011 to 2013.
eVs and electric heating equipment adoption trends, and
the resulting electric load profiles, were created for simulation in auroraXmP, which performed capacity expansion
and hourly, zonal economic dispatch spanning the new
york independent system operator (nyiso) and iso new
england (iso-ne) footprints from 2017 to 2030, while
maintaining minimum (15%) reserve margins. the study
also modeled monthly natural gas fuel price dynamics based

GHG Emissions
(Million Metric Tons CO2)

California Methodology

400
300
200
100
0

1990

2015

1990

2015

Residential Commercial
Industrial
Transportation
Electric Power-In State

figure 2. In-state fossil-fuel CO2 emissions in California
and the U.S. Northeast by sector, 1990 and 2015. (Data
source: U.S. EIA State Carbon Dioxide Emissions Data,
released October 2017.)
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Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - July/August 2018