guaranteed, and the stakes are high. With some three-quarters of GHG emissions stemming from

fossil fuel combustion, the US must rapidly scale clean electricity production while concurrently

electrifying high energy–use sectors and developing new technologies for emission sources that

the urgent combination of public policy implementation, technological progress, and changes to

operational norms and behaviors by both public and private sector actors.

There are reasons for optimism. While business-as-usual trendlines for the US fall far short of

to the $1.9 trillion spent on the American Rescue Plan in a single year. More will be required from

both public and private sectors for midcentury net-zero goals to become reality.

New US legislation must therefore galvanize momentum for scaling up the deployment of

established technologies and systems and accelerate the development and marketability of

those that are more nascent. Subsidies, mandates, and regulatory constraints have a history of

catalyzing demand shifts, innovation, price reductions, and new economies of scale—at times

the costs, hasten the uptake, and strengthen the performance of already competitive solar, wind,

and battery sectors, while setting the stage for rapid price competitiveness and wider readiness

improvements in next-generation technologies and infrastructure needed to decarbonize the

to bolster equitable investments; the necessity of advancing state and regional coordination,

particularly for grid systems; and the current and potential impacts of clean energy standards

and carbon pricing for US net-zero prospects.

The report seeks to strengthen the evidence base on what will be required for a robust US energy

transition, and to elucidate key barriers and pathways toward net-zero goals. It also serves as the

foundation for future work by Energy Pathways USA, which will provide in-depth and ongoing

analysis across these topics.

consumption has been remained relatively stable.

Paris Agreement pledges as a starting point, the Biden administration has updated the US

nationally determined contributions (NDCs) to the agreement with a GHG emissions target of

50% to 52% below 2005 levels by 2030 and economy-wide net-zero emissions “no later than 2050”

(The White House 2021a). This is a substantial increase in US ambition, moving from 2015 NDC

targets of 26% to 28% reductions below 2005’s levels by 2025 and 80% below 2005 levels by 2050.

Business-as-usual (BAU) scenarios, unsurprisingly, do not place the US on track to meet these

27.3% of all emissions. Prior to 2010, the electric power sector was the largest source with one-

(12.4%) and residential sectors (5.1%), respectively.

and 2% from wastes (wastewater treatment and burning). Nitrous oxide was 6.9% of the total in

Figure 3 complements these data by assigning fossil fuel CO

the year 2021. In this assignment, emissions associated with electricity generation are shared out

across consumers of the electricity; hence the right-hand column for the electricity sector replicates

the emissions that have already been included in yellow across the other sectors. By fuel, 45% of

CO

and represent an important component of industrial emissions.

a hypothesis worth examining in assessing the impacts of national versus regional or local policy

interventions. These states are clustered broadly in the middle of the country, with per capita

and commercial use also roughly follows weather patterns measured by heating degree days, with

colder states using more energy for heating purposes. Income distributions (not shown) also follow

a similar—though inverse—ranking across states, where poorer states are more concentrated

in the center of the nation, use more energy per capita, and thus could face higher burdens if

or unexpected outages of units. IEA global estimates likewise also see a large role in developed

backup has an important role, with more limited reliance on natural gas to remain available in the

long term to ensure the grid functions properly.

reached.

step for lowering economy-wide emissions. Figure 12 compares EV sales market share scenarios

trends) (Zhou and Mai 2021), and analysis from the Princeton net-zero study.

people’s willingness to adopt new technology are hard to incorporate fully into broad economy-

types are only one component of the EV adoption decision. More than a century of observing

vehicle purchases clearly shows that buyers do not simply buy the least costly option to travel;

issues of driving range and access to charging.

which compares the AEO Reference case forecast for electricity generation in the United States

reach 7,000 TWh by 2050 to supply EVs, instead of the 5,000 TWh that were required prior to the

vehicles or sectors of the economy.

modes of transport lend themselves to a wider array of technology choices than are expected in

LDVs (Figure 15).

cell vehicles for the US, with heavier trucks relying more on fuel cells.

hard-to-abate transportation areas (i.e., aviation and shipping).

and low-carbon trucks are already technically feasible, and that the best technology options for

primacy as the cost competitiveness of fuel cell vehicles is controlled by the cost of hydrogen,

which is in turn dependent on the price of electricity if it is derived from electrolysis. This calculus

heavy road transport.

case only eliminates most gas heat by 2045 (Figure 16). Similar trends are seen in commercial

heating and cooking, without the need for substantial increases in total electricity use.

not change in the net-zero scenarios. In other words, that behavior does not meaningfully change

industrial energy consumption into electricity and where other areas should be evaluated because