National Renewable Energy Laboratory

Advanced Heavy Hybrid Propulsion Systems

Millions of heavy trucks and buses are driven on U.S. streets and highways each day. Their sheer numbers mean that improving their emissions and fuel economy is critical to the nation's economic security and environmental well being.

NREL's Advanced Heavy Hybrid Propulsion Systems Project (AH²PS) focuses on improving these heavy trucks and buses. Teaming with the U.S. Department of Energy and industry, we're developing advanced heavy hybrid propulsion systems that are projected to increase the fuel efficiency of heavy trucks (Class 3-8) and buses by as much as 100%, and improve their emissions to meet the Environmental Protection Agency's 2007-2010 emission standards. Overall, AH²PS-developed technologies are projected to save more than 20 million barrels of oil in 2010 and 250 million barrels of oil in 2020.

NREL's AH²PS research is funded by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy. This work supports many NREL programs and is led by the Center for Transportation Technologies and Systems.