Skip to main content

Currently Skimming:

2 Opportunities for Deep Decarbonization in the United States, 20212030
Pages 55-116

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 55...
... . Electric power generation has been the real workhorse of emissions reductions, with carbon dioxide emissions from electricity generation declining by a third from 2005 to 2019 (EIA, 2020a)
From page 56...
... , the electricity sector could deliver as much as 90 percent clean electricity by 2035 at rates comparable to today's levels. Such an outcome could occur by retaining existing hydropower and nuclear capacity, accelerating deployment of wind and solar to displace coal and some gas-fired generation, retaining most existing natural gas power plants for reliability and flexibility purposes, and building out sufficient electric transmission capacity to connect new renewable generation to the grid (Phadke et al., 2020)
From page 57...
... While natural gas plants can continue to provide reliability and flexibility services in the near term, reaching a 100 percent carbon-free electricity sector will ultimately require deployment of one or more "clean firm" electricity sources, including geothermal energy, biogas, nuclear energy, natural gas with carbon capture and sequestration (CCS) , and hydrogen or other carbon-free fuels produced from net-zero carbon processes.
From page 58...
... economy as part of efforts to reduce net GHG emissions -- across all gases -- to zero by midcentury. Figure 2.2 provides an illustrative path to achieving net-zero emissions, in which gross carbon dioxide emissions from the end-use sectors are almost completely eliminated, and negative emissions technologies are scaled up to offset residual emissions from hard-to-abate energy sectors.
From page 59...
... Negative emissions technologies such as direct air capture and storage (DACS) and bioenergy with carbon capture and sequestration (BECCS)
From page 60...
... Examples include the unconventional gas tax credit for shale gas, production and investment tax credits for wind and solar, utility rebate programs for LEDs, and fuel economy and zero emissions vehicle standards and electric vehicle subsidies for lithium-ion batteries. Thanks to prior decades of investment and policy, all five of these technologies went from expensive "alternative energy" to cost-competitive, mainstream energy choices that are transforming the electricity, buildings and appliances, and transportation sectors and will enable costeffective and sustained reductions in GHG emissions over decades to come.
From page 61...
... (2019) , the high cost bound is in the low land negative emissions technologies (NETs)
From page 62...
... Estimates of the incremental cost of a net-zero transition have been decreasing over time as the costs of clean energy technologies (e.g., wind, solar, and electric vehicles) have been declining, indicating that innovation can further decrease the costs of the clean transition.
From page 63...
... Failure to replace retiring infrastructure with efficient, low-carbon successors will either result in the inability to meet emission-reduction targets or require early retirement of the replacement equipment, leading to sunk costs and stranded assets. Recent studies see the 2020s as the time to build out enabling infrastructure for the net-zero transition and end most new investments in infrastructure to transport fossil fuels (e.g., pipelines)
From page 64...
... However, transitioning to near-zero emissions from electricity generation requires replacing the vast majority of fossil fuel power plants or equipping them with carbon capture technologies (Jenkins et al., 2018)
From page 65...
... Some pathways are constructed using leastcost models that deploy or retire energy infrastructure based on the lowest cost of meeting energy demand without emissions. Least-cost models generally employ a broad range of zero-carbon technologies, although such models may not account for permitting and siting, regulatory, financing, or other barriers.
From page 66...
... All plausible pathways to zero emissions share core features: decarbonizing electricity; switching to electricity and other low-carbon fuels for energy services in the transportation, industry, and buildings sectors; increasing energy efficiency in each of those sectors, in the power sector, and in materials; increasing carbon sequestration, and reducing emissions of non-carbon climate pollutants. In particular, there is strong agreement among deep decarbonization studies on the following points: • Energy and materials efficiency: One of the lowest-cost decarbonization oppor tunities helps to reduce the overall need for low-carbon fuels and electricity, and will continue to be important across all economic sectors through the next 30 years (Williams et al., 2014; White House, 2016)
From page 67...
... . • Electrify energy services that directly use fossil fuels at the rate of 10 to 50 percent of new light-duty vehicles, and heat pump electrification of space heating and water heating in 15 to 25 percent of residences, with all new construction to be fully electric in order to achieve >50 percent of building energy supplied by electricity by 2030 (up from ~44 percent today)
From page 68...
... Metrics for three of the most recent and comprehensive studies are reported in more detail in Table 2.1. The scenarios analyzed in these studies projected energy demand, share of non-emitting electricity, share of electricity in final energy demand, energy productivity, and scale of CCS, land sinks, hydrogen production, impact of non-CO2 gases, building energy intensity, and EV share.
From page 69...
... e Carbon capture (MMT CO2/yr) 0 30.6 ND 65–197 26 775 690–1760 Land sinks (MMT CO2/yr)
From page 70...
... Assumes an enhanced land sink 50 percent larger than the current annual sink. Assumes that nuclear plants already in operation will be operated and retired based on the schedule in the 2017 Annual Energy Outlook.
From page 71...
... Energy and materials efficiency is one of the most cost-effective near-term approaches to reduce energy demand and associated emissions. This approach includes adopting developing technologies and processes that increase fuel efficiency of vehicles (on-road and off-road, including farming equipment)
From page 72...
... of off-site renewable energy. It is also critical to work toward maximum condition ing goals for new construction that reflect passive house site energy stan dards of 5–60 kBtu/ft2/year (depending on climate and building type)
From page 73...
... Among LDVs, electric vehicles are projected to reach cost-parity with internal combustion engine vehicles in the next decade and, in conjunction with relatively low-carbon electricity, will also reduce emissions. Some potential exists for electrification of industrial processes, although electrification technologies for the industrial sector are at a relatively early stage of development and play a greater role beyond the 2030 time frame, as electrification technologies mature, decline in cost, and are demonstrated at scale.
From page 74...
... and 15 percent of on road fleet will be electric vehicles (with some fuel cell EVs in the MDV and HDV subsectors)
From page 75...
... units retire, and to provide system flexibility alongside wind, solar, and storage, while avoid ing new commitments to long-lived natural gas pipeline infrastructure. º Energy storage: Deploy 10–60 GW / 40–400 GWh of intraday energy stor age capacity (e.g., battery energy storage)
From page 76...
... º Expand smart grids: Expand automation and controls across electricity dis tribution networks and end-use devices by increasing the fraction of elec tricity meters with advanced two-way communications capabilities from about half to 80 percent. Smart grid expansion will enable greater demand response of EV charging, space and water heating loads, and cooling energy storage for air conditioning buildings.
From page 77...
... Complete one or more demonstrations of large-frame combustion tur bine operations consuming greater than 20 percent hydrogen (by energy content) on an annual basis through typical operational cycles for multiple years to reduce technology risk and identify longevity and operability challenges with high hydrogen/natural gas blends.
From page 78...
... to regions of high CO2 use potential or storage. Development of a CO2 network could involve repurposing existing natural gas or oil pipeline infrastructure or rights-of-way.
From page 79...
... º Improve long-duration energy storage for deployment with the electric grid and renewable energy to operate at an ultra-low cost per kWh (~ $1/kWh) and long asset life (e.g., 10–30 years)
From page 80...
... In natural gas and oil systems, significant mitigation of non-CO2 emissions can be achieved through changes in operational practices, including directed inspection and maintenance. In coal mining, reduction of ventilation air methane and degasification for power generation and pipeline injection represent most of the abatement potential.
From page 81...
... . Including bioenergy with carbon capture and sequestration plants and waste biomass capture could remove another 500 MtCO2 at less than $100/tCO2.
From page 82...
... The costs for deep decarbonization also must be considered in the context of the considerable benefits of a clean energy transition that could offset some, all, or more than the cost of the transition. There are climate benefits, new economic and employment opportunities, substantial improvements in public health, and intangible global leadership credentials.
From page 83...
... ; and a reduction of up to 200,000 annual premature deaths from eliminating air pollution from fossil fuels entirely (Lelieveld and Münzel, 2019)
From page 84...
... Other potentially significant changes in capital expenditures are not estimated in the above figure, including changes in natural gas, coal, and oil transportation and delivery networks, establishment of bioenergy crops, decarbonization measures in other industries besides cement and hydrogen production, and efficiency improvements in aviation, rail, and shipping. SOURCE: Committee generated using data from Larson et al.
From page 85...
... Electricity Wind 110 414 Solar 62 374 Natural gas CT and CCGT 101 112 Natural gas with CCS 0 0 Li-ion battery storage 3 3 Biomass with CCS 0 2 Networks Electricity transmission 203 356 Electricity distribution 352 369 EV chargers 1 7 CO2 storage 0 11 CO2 transportation 0 68 Fuels and industry H2 -- gas reforming 3 3 H2 -- gas reforming with CCS 0 7 H2 -- biomass gasification with CCS 0 0 Electric boilers 0 12 Gas boilers 5 5 Cements with CCS 0 9 DRI steel 0 0 Total supply side capital expenditure, 2021–2030 840 1,752 NOTE: The Princeton Net-Zero America analysis (Larson et al., 2020) quotes both total capital in service for projects that come online from 2021 to 2030 and total capital mobilized, which includes capital being spent in the 2020s for projects that come online post-2030.
From page 86...
... Policy makers should look to enhance positive synergies while managing negative synergies and unintended consequences. Positive synergies could include decarbonizing both the industrial and transportation sectors with hydrogen, synthetic net-zero carbon fuels, and CCS; facilitating decarbonization of transportation and the built environment through smart growth policies; and developing more efficient energy end-use equipment to provide greater opportunities to manage load and reduce the need for fossil fuels in end-use sectors and electricity generation.
From page 87...
... new buildings and 50 percent reduction for existing buildings by 2050. Transportation • Transition • Aggressively pursue • Pursue energy efficiency for • Invest in ubiquitous EV • Reduce costs of to multiple zero emission vehicle infrastructure construction charging infrastructure.
From page 88...
... Electrical • Target widespread • Expand adoption of • Where cost effective, install • Develop and deploy • Invest in energy energy storage adoption of electrified vehicles onsite energy storage to low-emissions storage RD&D electrified personal through lower cost and accommodate peak usage manufacturing and to lower costs, and commercial higher energy density demands. processing of energy facilitate recycling, vehicles, buses, batteries.
From page 89...
... generation to reduce fossil fuel burning power plants and peaker plants. Fuels • Employ electrolysis as • Expand ability to • Drive RD&D to a flexible consumer of blend H2 into natural use green H2 in electricity to produce gas by upgrading fuel formation zero-carbon fuels and valves, controls, and processes (e.g., feedstocks.
From page 90...
... . distributed energy • Decrease natural gas-fired resources to generation by ~10–30 improve network percent by 2030 and asset utilization keep capacity roughly flat and efficiently nationally accommodate increased demands from electric vehicles, heat pumps, and other new loads.
From page 91...
... NOTE: CCS = carbon capture and sequestration; EV = electric vehicle; ICE = internal combustion engine; RD&D = research, development, and demonstration.
From page 92...
... highlight the committee's evaluation of technologies and approaches required in 2021–2030 to remain on the trajectory for full decarbonization by 2050, organized by sector. Energy demand, supply, carrier, and storage approaches are discussed, including needs for buildings, transportation, industry, energy storage, fuels, electricity generation and transmission, and carbon capture and sequestration.
From page 93...
... . The built environment can significantly reduce its energy demand, its share of electricity demand, and its embodied carbon.
From page 94...
... . Six overarching goals and strategies to achieve building demand reduction and decrease carbon emissions from the building sector are described below: 1.
From page 95...
... Buildings have a role in electricity generation, storage, and carbon sequestration as well. Buildings and commu nities play a significant role in decarbonizing energy supply through the following: º Electrification of the built environment with the lowest conditioning, process, plug and parasitic loads through conservation, passive conditioning, and energy cascades; º Peak load shaving and demand flexibility; º District and building CHP for 150 M MtCO2/yr; continued 95
From page 96...
... This should be followed by integrating site and community renewable energy sources with effective grid integra tion and energy storage, wherever cost effective. These actions should fully anticipate the elimination of fossil fuels and combustion in buildings, with building electrifica tion as a linchpin solution for decarbonization of the United States.
From page 97...
... Fuel cell vehicles still have a sizable cost premium and limited hydrogen filling stations. With the continued improvement in battery performance, the extra cost of battery electric vehicles is ex pected to be small by 2025 (Lutsey and Nicholas, 2019)
From page 98...
... Process heat uses 61 percent of the on-site energy accounting for 32 percent of GHG emissions and 7 percent of GHG emissions across sectors, with 90 percent from fossil fuels (DOE, 2015c; EIA, 2020e)
From page 99...
... Energy efficiency. Accelerate low-capital solutions (e.g., energy, materials, system efficiency; separations, intermittent fuel switching)
From page 100...
... . Fast charging stations should be accompanied by renewable energy generation where large loads can be offset through local energy storage and the likelihood of >1 MW being drawn from the grid at once is mitigated (Bhatti et al., 2016)
From page 101...
... 3. Develop low-cost, environmentally benign, safe, long-life electrochemical energy storage for use with renewable energy generation to provide flexibility of site selection, including a range of designs and capabilities suitable for cycling over intraday, interday, and weekly time periods or longer.
From page 102...
... a Conventional natural gasb 3 Conventional industrial H2 from natural gasc 7 Conventional gasolined 15 Renewable hydrogen from electrolysise 35 Renewable CO2 gasolinef 55 Renewable ethanol fuelg 16 Ammonia from methaneh 22 Renewable ammoniai 30 a Note that these numbers come from different sources with different assumptions and so provide general guidance on pricing, but all can move up or down based on assumptions (e.g., electricity prices)
From page 103...
... is a non-drop-in fuel and the lowest cost synthetic fuel per energy content. It can be produced by the electrolysis of water using renewable energy sources, via steam methane reforming and autothermal reforming of natural gas (including with CCS, rendering the process zero- or near-zero carbon)
From page 104...
... greenhouse gas emissions and with mul tiple scalable, affordable alternatives to fossil fueled power plants available today, the electricity sector must (and can) cut emissions faster and deeper than any other sector (Phadke et al., 2020; Haley et al., 2019; Vibrant Clean Energy, 2019)
From page 105...
... . Storage will likely play a larger role from 2030–2050; during this period, production of hydrogen, ammonia, or synthetic methane from carbon-free electricity can offer a form of longer-term chemi cal energy storage, and these energy carriers can be used as fuels (or feedstocks)
From page 106...
... indicates retirement period of the coal and natural gas power fleets along with the number of units (above bars) and cumulative capacities assuming an average age of 40 years.
From page 107...
... (Start Date; Scale) Natural Gas 700 3–5 ~9–10 ~55–60 Elk Hills, Fluor (2020; Mt/yr)
From page 108...
... (Reddy and Freeman, 2018) , are a good match for retrofitting natural gas plants retiring beyond midcentury.
From page 109...
... Some actions could be implemented immediately with existing technology but need to begin, such as replacement of building heating with electric equipment, widespread deployment of electric vehicles, and blending of hydrogen with natural gas in industrial infrastructure and equipment. Other actions, such as carbon capture, require improvement and maturation of existing technologies or new technology or approaches to be developed and tested at scale, and research, development, and deployment in these areas must be accelerated in the decade after the release of this report to provide options in 2030–2050.
From page 110...
... Washington, DC: Office of Technology Transitions. DOE-EERE (Department of Energy Office of Energy Efficiency and Renewable Energy)
From page 111...
... Greenhouse Gas Emissions and Sinks: 1990–2018. Washington, DC.
From page 112...
... Geneva, Switzerland: Intergovernmental Panel on Climate Change. IRENA (International Renewable Energy Agency)
From page 113...
... 2011. Life cycle environmental assessment of lithium-ion and nickel metal hydride batteries for plug-in hybrid and battery electric vehicles.
From page 114...
... Energy Use and Greenhouse Gas Emissions in Scenarios with Widespread Electrification and Power Sector Decarbonization. Golden, CO: National Renewable Energy Laboratory.
From page 115...
... 2020. Forecasting the value of battery electric vehicles compared to internal combustion en gine vehicles: The influence of driving range and battery technology.


This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More information on Chapter Skim is available.