The Understand Energy Learning Hub is a cross-campus effort of the Precourt Institute for Energy.

Understand Energy Learning Hub

Energy for Transportation

Fast Facts About
Energy for Transportation

Transportation provides mobility and access to goods and services. Transportation modes for passengers and freight include road transport, maritime, rail, aviation, and pipelines.

Over 90% of transportation is fueled by oil, and transportation accounts for almost two thirds of the oil used worldwide. Transportation is responsible for 15% of global Greenhouse Gas (GHG) emissions and is a major contributor to other air pollutants that affect human health. Negative impacts disproportionately affect lower income communities and communities of color.

Short distance travel is the easiest place to decarbonize transportation. Cars, light trucks, and motorcycles account for approximately 60% of energy used in transportation, and 98% of those vehicles run on gasoline. Because gasoline-powered vehicles are extremely inefficient (less than 1% of the car’s fuel moves the driver), decarbonizing personal vehicles is a priority and opportunity for reaching climate change goals. Electric vehicle (EV) use is one of the main ways to achieve this.

Long-distance travel via air, maritime, and long-haul road, on the other hand, is harder to decarbonize. Policy can play a big role in driving clean transportation forward.

Significance

Total Final Energy Consumption

World 29% 🌎
US 27% 🇺🇸
of total final energy consumption is used in transportation

GHG Emissions

World 15% 🌎
US 29% 🇺🇸
of GHG emissions come from transportation

Transport Fuels

Oil Dominates Transport Fuels

Note: Natural gas is mostly used in pipelines to move natural gas.

Breakdown of fossil fuels used:

  • Trucks and Buses: Fuel use is 96% fossil fuels in the form of diesel (81%), gasoline (11%), and natural gas (3%). (Percentages are rounded to nearest percent.)
  • Aviation: Fuel use is virtually 100% fossil fuels (all jet kerosene).
  • Shipping: Fuel use is virtually 100% fossil fuels in the form heavy fuel oil (HFO), marine gas oil (MGO), and marine diesel oil (MDO). 
  • Rail: Fuel use is 52% fossil fuels (all diesel) and 48% electricity.

Transport Modes

Light-Duty Vehicles* Dominate Transport Energy Use

*Light-duty vehicles include automobiles, light trucks, and motorcycles. Medium-duty vehicles generally weigh between 14,000 and 26,000 pounds. They include vans for more than 10 persons, buses, campers, pick-up trucks. Heavy-duty vehicles weigh between 26,001 and 33,000 pounds. They include heavy-duty pickup trucks and vans, heavy-duty work trucks, and heavy-duty trailers.

Energy Intensity of Transport Modes

World

Largest Vehicle Fleets

United States 19% 🇺🇸
China 17% 🇨🇳
of the 1,490 million total registered vehicles in 2019

Largest Vehicle Fleets per Capita

United States 908 🇺🇸
New Zealand 884  🇳🇿
per 1,000 people

(China ranks 45th with 226 per 1,000 people)

Increase in Global Vehicle Fleet

⬆ 23%
(2014-2019)

Largest EV Penetration

Norway 88% 🇳🇴
Iceland 70% 🇮🇸
of overall car sales

Global EV Stock Share

2%
of all registered cars

14%
of new car sales

Increase in Global EV Fleet

⬆ 735%
(2017-2022)

US

Largest Vehicle Fleets

California 11%
Texas 8%
of the 276.5 million total registered vehicles in 2019

Largest Vehicle Fleets per Capita

Montana 1,778
Wyoming 1,458
South Dakota 1,448
per 1,000 people

(California ranks 44th with 791 per 1,000 people)

Increase in US Vehicle Fleet

⬆ 11%
(2014-2019)

Largest EV Penetration

Washington D.C. 8.2%
California 7.7%
of light-duty vehicle registration by state in 2022

US EV Stock Share

1%
of all registered cars

8%
of new car sales

Increase in US EV Fleet

⬆ 289%
(2017-2022)

Opportunities for Decarbonizing and Improving Transportation

  1. Design for less transportation: walkable and bikeable cities, remote learning and work, supply-chain optimization (e.g., domestication and near-shoring), reduced consumption.
  2. Optimize overall transport system. Promote modal shift of freight and passengers from more carbon-intensive modes of transportation (e.g., individual cars, trucks and planes) to less carbon-intensive modes (e.g., public transport, rail, biking).
  3. Promote behavioral change (e.g., walking and biking when possible, smart delivery instead of express delivery to reduce air demand).
  4. Electrify and transition to cleaner fuels (e.g., sustainable aviation fuels - SAF, green methanol for shipping, hydrogen).
  5. Adjust gasoline, diesel, and jet fuel prices to reflect their social and environmental costs (e.g., carbon tax).
  6. Smart transport: use of data analytics, artificial intelligence, and Internet of Things (IoT) devices to optimize routing and reduce fuel consumption.

Road

  1. Electrification of passenger vehicles and motorbikes.
  2. Direct regulation such as emission and efficiency standards.
  3. Reduce embodied energy through increased utilization and improved component recycling.
  4. Increase vehicle and infrastructure efficiency (e.g., use of roundabouts, timing of lights, etc.).

Air

  1. Fleet renewal to reduce fuel consumption.
  2. Improve operational efficiency (e.g., routes and airports).
  3. Electrification of support systems in airports.
  4. Ticket pricing mechanisms that reflect social and environmental costs of air travel.
  5. Use of decarbonized fuels (e.g., sustainable aviation fuel (SAF)).

Rail

  1. Improve service quality to increase ridership.
  2. Invest in high-speed rail networks, which are more energy-efficient than conventional rail systems.

Maritime

  1. Use of wind-assisted propulsion systems like sails, rotors, or kites to reduce use of fossil fuels.
  2. Retrofit existing vessels to improve energy efficiency.
  3. Use of decarbonized fuels (e.g., green methanol).

Drivers and Barriers for Decarbonizing and Improving Transportation

Drivers

  • Need to reduce GHG emissions
  • High environmental impacts, including air pollution, land and water pollution, and resource use
  • Equity and justice concerns; disproportionate negative impacts for low income communities, and lack of access to affordable transportation
  • High mortality rate from car crashes
  • Congestion that leads to lower productivity, stress, and air pollution
  • Efficiency gains from electrification
  • Policy incentives: subsidies for EV manufacturing and sales, congestion charges in cities, subsidies for clean fuel development
  • Opportunities and options to decarbonize short distance travel including EVs, urban infrastructure to promote walking and biking (e.g., sidewalks, dedicated bike paths, bike-sharing programs), investing in public transport

Barriers

  • Gasoline and diesel are poorly priced globally; they do not reflect the full social costs of using them
  • High capital costs of EVs
  • Lack of charging infrastructure and need to optimize EV charging on the grid
  • Uncertain / Underdeveloped policy landscape (e.g., lack of comprehensive and globally harmonized regulatory frameworks for SAF production, distribution, and use; inconsistencies in certification and regulation for clean fuels)
  • Need to improve costs and reduce environmental impacts of battery life-cycle
  • Human rights and geopolitical challenges in sourcing materials for batteries
  • Need for behavioral and lifestyle changes
  • Hard to decarbonize modes (long-haul trucking, airplanes, ships)
  • Technological and supply challenges for cleaner fuels like hydrogen or sustainable aviation fuels

Climate Impact: High*

High gradient
  • Transportation is a major contributor of GHG emissions

Environmental Impact: High*

High gradient
  • Air pollution from NOx, SOx (→ acid rain), ozone, particulate matter (PM) (→ smog)
  • Land and water pollution
  • Resource use for car manufacturing and for roads and parking spaces

*These impacts are dependent on the mode of transportation and fuels used. They are high because currently transportation mostly uses fossil fuels. As other modes of transport are used and cleaner vehicles are used, the impacts can be reduced.

Sources
Printable PDF

Updated October 2023

Before You Watch Our Lecture on
Energy for Transportation

We assign videos and readings to our Stanford students as pre-work for each lecture to help contextualize the lecture content. We strongly encourage you to review the Essential readings and videos before watching our lecture on Energy for Transportation. Include selections from the EV Commercials and Optional and Useful lists based on your interests and available time.

Essential

EV Commercials

Meant to be thought-provoking about how EV commercial messaging might resonate (or not) with different communities and how the messaging has changed over time.

Optional and Useful

Our Lecture on
Energy for Transportation

This is our Stanford University Understand Energy course lecture on energy for transportation. We strongly encourage you to watch the full lecture to understand the impacts of transportation on our energy system and how transportation systems are finally changing to become cleaner and more efficient. For a complete learning experience, we also encourage you to watch / read the Essential videos and readings we assign to our students before watching the lecture.

Diana Gragg

Presented by: Diana Gragg, PhD; Core Lecturer, Civil and Environmental Engineering, Stanford University; Explore Energy Managing Director, Precourt Institute for Energy
Recorded on: October 25, 2023   Duration: 90 minutes

Table of Contents

(Clicking on a timestamp will take you to YouTube.)
00:00 Introduction 
07:28 Big Picture 
19:11 Externalities & Policy 
27:40 Air Pollution Regulation & Fuel Policies 
43:44 Vehicle Efficiency Standards 
52:11 Electrification of Transportation 
1:05:11 Vehicle Miles Traveled 
1:08:27 Embodied Energy 
1:20:10 Future of Transportation

Lecture slides available upon request.

Additional Resources About
Energy for Transportation

Stanford University

Government and International Organizations

Next Topic: Industry Decarbonization Other Energy Topics to Explore

Fast Facts Sources
Transport Energy Use by Mode: World 2018 (Energy consumption in transport in IEA countries, 2018, IEA).
EV Share of Registered Cars: World 2022 (Global EV Data Explorer, IEA, EV sales, cars, World, 2010-2022).
Total Transport Final Energy Consumption: World 2019 (Key World Energy Statistics 2021, IEA, World Total Final Consumption by Source 1971-2019), U.S. 2022 (Energy Use for Transportation, EIA, Monthly Energy Review Table 2.1).
Transportation GHG Emissions: World 2020 (Historical GHG Emissions, Climate Watch, Global Historical Emissions 1990-2020), U.S. 2021 (Inventory of U.S. Greenhouse Gas Emissions and Sinks, EIA,  U.S. Greenhouse Gas Emissions by Economic Sector).
Global Energy Consumption in Transport by Fuel: World 2022 (Energy consumption in transport by fuel in the Net Zero Scenario, 1975-2030, IEA), U.S. 2021 (Transportation Energy Data Book: Edition 40, Oak Ridge National Laboratory, Distribution of Transportation Energy Consumption by Source, 1950–2021 Table 2.4).
Fuel Use by Transport Mode: World 2022 (IEA Transport: Tracking Trucks and Buses (Energy). Tracking Aviation (Technology Deployment). Tracking Shipping (Energy). Tracking Rail (Energy)).
Transport Energy Use by Mode: World 2018 (Energy consumption in transport in IEA countries, 2018, IEA), U.S. 2021 (Energy Use for Transportation, EIA, Annual Energy Outlook 2023 Table 35).
Definition of Light-Duty, Medium-Duty, and Heavy Duty Vehicles: U.S. 2023 (Code of Federal Regulations, 49 CFR 523.2 Definitions)
Energy Intensity of Freight Transportation: U.S. 2013 (Ristinen, R.,  Kraushaar, J., Brack, J (2016). Energy and The Environment, Table 8.2 Energy Efficiency Estimates for Various Forms of Transportation).
Energy Intensity of Passenger Transportation: World 2018 (Energy Intensity of Passenger Transport Modes, IEA).
Largest Vehicle Fleet: World 2019 (Transportation Energy Data Book: Edition 40, Oak Ridge National Laboratory, Car, Truck and Bus Registrations for Selected Countries, 1960–2019 Table 3.2 and Table 3.3), U.S. 2019 (Transportation Energy Data Book: Edition 40, Oak Ridge National Laboratory, Motor Vehicle Registrations by State and Vehicle Type, 2019 Table 3.5).
Largest Vehicle Fleet Per Capita: World 2020 (Motorization Rate, OICA, Total World Vehicles in Use), U.S. 2019 (Motor Vehicle Registration: Transportation Energy Data Book: Edition 40, Oak Ridge National Laboratory, Motor Vehicle Registrations by State and Vehicle Type, 2019 Table 3.5, Population: 2019 National and State Population Estimates, United States Census Bureau, Table 1).
Increase in Vehicle Fleet: World 2014-2019 (Transportation Energy Data Book: Edition 40, Oak Ridge National Laboratory, Car, Truck and Bus Registrations for Selected Countries, 1960–2019 Table 3.2 and Table 3.3), U.S. 2014-2019 (Transportation Energy Data Book: Edition 40, Oak Ridge National Laboratory, Car, Truck and Bus Registrations for Selected Countries, 1960–2019 Table 3.2 and Table 3.3). 
Largest EV Penetration: World 2022 (Global EV Data Explorer, IEA, EV sales, cars, World, 2010-2022), U.S. 2022 (Vehicle Registration Counts by State, DOE, 2022 Light-Duty Vehicle Registration Counts by State and Fuel Type).
EV Share of Registered Cars: World 2022 (Global EV Data Explorer, IEA, EV sales, cars, World, 2010-2022), U.S. 2022 (Global EV Data Explorer, IEA, EV sales, cars, World, 2010-2022).
EV Share of New Car Sales: World 2022 (Global EV Data Explorer, IEA, EV sales, cars, World, 2010-2022), U.S. 2022, U.S. 2022 (Global EV Data Explorer, IEA, EV sales, cars, World, 2010-2022).
Increase in EV Fleet: World 2017-2022 (Global EV Data Explorer, IEA, EV sales, cars, World, 2010-2022), U.S. 2022 (Global EV Data Explorer, IEA, EV sales, cars, World, 2010-2022).
More details available on request.
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