U.S. Department of Energy - Energy Efficiency and Renewable Energy

Vehicle Technologies Office – Advanced Vehicle Testing Activity

What Is Hydrogen Blending?

Tanks at the Hydrogen Fueling CenterWhen used as a fuel in internal combustion engines (ICEs), either as 100% hydrogen or blended with compressed natural gas (CNG), hydrogen appears to offer reduced air emissions and maintenance benefits, and it may provide power benefits as will. However, the economics of vehicles using these fuels is not well defined. Concurrently, hydrogen infrastructure requirements, including hydrogen production and storage, are another are that requires greater understanding and development.

The Advanced Vehicle Testing Activity (AVTA) has teamed with Pinnacle West (holding company of Arizona Public Service) and Electric Transportation Applications to construct and operate a hydrogen and compressed natural gas (H/CNG) generation and fueling facility in Phoenix, Arizona. The APS Alternative Fuel Pilot Plant provides pure hydrogen, pure CNG, or H/CNG (blends to the various ICE test vehicles as well as fuel cell vehicles being tested by original equipment manufacturers (OEM) at some of the seven test tracks in the Phoenix area.

HOGEN GeneratorThe H/CNG facility is used to fuel ICE test vehicles that require 100% hydrogen, 100% CNG, or H/CNG blended fuels. Some of these test vehicles have included a 100% hydrogen ICE Mercedes-Benz van and two 100% hydrogen ICE Ford F-150 pickups. In addition to the above vehicles, the AVTA and its testing partners have initiated fleet testing of H/CNG ICE vehicles operating at 15-50% H/CNG in a fleets in the greater Phoenix area. After completing the development of hydrogen ICE vehicle testing procedures and specifications, the 100% hydrogen-power ICE Ford F-150 pickups have entered baseline performance and accelerated reliability testing.

Compressed Natural Gas CompressorIn addition to providing hydrogen-powered ICE vehicle knowledge, operating these vehicles provides hydrogen and H/CNG fueling interface experience. When additional 100% hydrogen and H/CNG blend ICE vehicles become available they will be evaluated as candidates for testing.

Hydrogen is also widely anticipated to be the future fuel of choice for vehicles equipped with fuel cells, but currently, no commercially viable fuel cell vehicles are available for testing. However, development of fuel cell vehicles continues in earnest, and the AVTA is developing the hydrogen infrastructure necessary to test these vehicles when they are become available.