Published on December 3rd, 2016 | by James Ayre2
Report: Hydrogen Fuel Cell Bus Fuel Economy Only 1.4 Times Better Than Diesel Buses
While hydrogen fuel cell buses may well prove to be the best choice in some niche applications, it seems that the fuel economy claims used by some proponents to date to argue for their use aren’t very accurate, going by a new report from NREL.
The exacts: the average fuel economy of the hydrogen fuel cell electric buses being used in the 3 demonstration projects (all in California) analyzed in the report works out to ~6 miles per diesel gallon equivalent (DGE). This fuel economy figure is roughly 1.4 times higher than the average for conventional diesel buses (~4.2 miles per DGE) and also a fair bit higher (1.9 times) than the fuel economy average of studied compressed natural gas (CNG) buses, which is ~3.3 miles per DGE. Battery-electric buses have a DGE of 17 (or more precisely, 17.48).
The press release provides more: “This demonstrates significant fuel economy improvement toward the DOE and Federal Transit Administration’s (FTA) target of 8 miles per DGE. FCEB durability has reached 23,000 hours, surpassing FCTO’s 2016 target of 18,000 hours, and range has reached up to 340 miles, more than 13% above our 2016 target of 300 miles.”
Perhaps. But if that target still ends up being below what all-electric buses can manage, then what’s the point of using the technology in anything but niche applications? Again, the DOE target for hydrogen fuel cell buses is 8 DGE while battery-electric buses already get over 17 DGE.
Continuing: “The 2016 report focuses on the August 2015–July 2016 time period for 3 demonstrations: the Zero Emission Bay Area Demonstration Group, the American Fuel Cell Bus Project at SunLine Transit Agency in California, and the American Fuel Cell Bus Project at the University of California at Irvine (UCI). The results for these buses account for more than 550,000 miles traveled and 59,500 hours of fuel cell power system operation.”
The findings and report (“Fuel Cell Buses in US Transit Fleets: Current Status 2016”) are part of NREL’s annual summarization of hydrogen fuel cell electric bus development in the US.
While I’m skeptical of the technology as a whole, I’m a bit curious to see how much fuel economy can be increased before hard limits are reached.