From the Introduction: "Congress maintains a continuing interest in reducing petroleum-based fuel consumption and greenhouse gas (GHG) emissions in transportation. [...] To achieve petroleum consumption and GHG emission reduction goals, Members of Congress introduced numerous legislative proposals that would have promoted the deployment and use of alternative fuels (AFs)--such as biofuels, hydrogen, and electricity--and alternative fuel motor vehicle (AFV) technology--such as flexfuel, fuel-cell, and electric vehicles (see 'Alternative Fuels and Alternative Fuel Vehicles'). The use of alternative fuels and vehicles has the potential to reduce the transportation sector's overall emissions of GHGs, particulate matter, and other air pollutants, by reducing the consumption of petroleum fuels. The potential for any such reduction varies depending on the fuels and vehicles that gain in widespread use compared to their conventional counterparts. [...] Some of these proposals were enacted during the 116th Congress, including provisions to extend existing tax incentives, grant and loan programs, and research and development activities. This report examines provisions within legislative proposals that would support the broader deployment of alternative fuels and alternative fuel vehicles; a discussion of relevant enacted legislation, including definitions of alternative fuels and vehicles found in statute; identification of major barriers and obstacles to increasing deployment of AFs and AFVs; and an analysis of legislation introduced in the 116th Congress."
CRS Report for Congress, R46864
Congressional Research Service: https://crsreports.congress.gov/