IEEE Power & Energy Magazine - July/August 2018 - 132

in my view

James H. Williams

the electric economy
moving toward a low-carbon future

REDUCInG CARBOn DIOxIDE
(CO2) emissions to the level needed to
stabilize the climate will require very
deep reductions in emissions from energy suppliers and end users. In Europe,
the United States, and other industrialized countries, this means reducing CO2
from fossil-fuel combustion at least 80%
below present levels by mid-century and
eliminating the emissions altogether a
decade or two after that. The technology
pathways for achieving such reductions,
while maintaining an energy system that
supports a modern economy, have recently begun to be spelled out in considerable detail in many countries, across
sectors, and over time.

Electricity and
Deep Decarbonization
Everywhere, the basic formula is the
same. There are three pillars required to
support a decarbonized energy system:
highly efficient energy use, electricity produced with virtually no carbon
emissions (much lower than possible
with a natural-gas-based generation
fleet), and end uses that mostly run on
low-carbon electricity. These pillars
stand up across geographies and stages
of economic development because they
embody basic physics and chemistry.
There is a role for other types of
low-carbon fuels; for example, biofuels
may prove essential in aviation and
shipping. But biofuels are fundamenDigital Object Identifier 10.1109/MPE.2018.2820446
Date of publication: 18 June 2018

132

ieee power & energy magazine

tally constrained in quantity, given existing technology and land-use practices. Carbon capture and storage (CCS),
which could allow the continued use
of fossil fuels in power generation and
industry, are constrained by the slow
pace of technology development and,
frankly, a lack of interest among policy
makers and the fossil-fuel industry.
The upshot is that currently there is
no feasible alternative to electricity in
most end-use applications-automobiles, buildings, industry-for supplying the low-carbon energy required.
A mostly fossil-fuel-free energy system means a major increase in electricity generation in the United States,
roughly a doubling from current levels
by mid-century, even accounting for
the offset of some load by behind-themeter solar photovoltaics (PVs). This
realization has not yet been absorbed in
some quarters. Many utilities see low
or negative load growth at present and
project that into their long-term load
forecasts. Yet an economy-wide lowcarbon transformation by mid-century
will require light-duty vehicles and
buildings to be more than 90% electrified and for industry to double its current electrification rate. This means a
lot of new load to be met by a lot of new
low-carbon generation.
Without a revival of nuclear power,
or an unexpected emergence of CCS,
most of the low-carbon electricity
needed will be provided by renewable
energy, especially wind and solar. Great
progress has already been made in actu-

al practice in integrating renewables at
levels of around one-third of total generation, and there is now widespread confidence in the ability of many systems
to reach well above this share. However,
above about a two-thirds share of intermittent power, especially with a limited
carbon budget for gas generation, a new
mix of solutions for addressing energy
imbalances will be required, including
thermal, curtailment, storage, and increased load and resource diversity from
expanded regional integration. Flexible
electric loads, including the production
of fuels like hydrogen and synthetic natural gas, may become key parts of the
balancing mix by mid-century.

Electrification
and Energy Efficiency
Integrating high levels of renewable generation poses some engineering-economic challenges, but it has a market driver
in falling wind turbine and PV module
prices, and it is widely understood to be
the path forward for power systems in a
climate-friendly world. The next frontier
of decarbonization is widespread electrification. This will be driven, in part,
by consumer demand and technological
improvements, as we are beginning to
witness with electric vehicles (EVs) and
battery prices. But markets often need to
be kick-started by policy, and that will
require broad-based support. The need
for electrification hasn't yet been universally embraced, especially in buildings
(continued on p. 128)
july/august 2018

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