Connect with us

Hi, what are you looking for?

CleanTechnica

Batteries

Electric Buses Efficient As He**, NREL Finds

Originally published on EV Obsession.

Proterra electric buses

A new analysis of a recent 12-vehicle Proterra electric bus demonstration (put on by Foothill Transit in California) by the National Renewable Energy Laboratory has found that these buses possess an average fuel economy roughly 4 times higher than that of baseline CNG buses.

The exact comparison shows an overall average efficiency of 2.15 kilowatt-hours (kWh) per mile for the electric buses, which equates to 17.48 miles per diesel gallon equivalent, and an average fuel economy of 4.04 miles per gasoline gallon equivalent for the compressed natural gas (CNG) buses, which equates to 4.51 miles per diesel gallon equivalent.

image

The National Renewable Energy Laboratory (NREL) analysis found that reliability was also quite high — with the number of miles between road calls averaging more than 9000. Only 3 of these road calls during the data period (April 2014 through July 2015) were pertaining to battery system issues. This is apparently “exceptional for an advanced technology bus in the early stage of commercialization.”

Here are some of the other findings of the analysis (via Green Car Congress):

  • The average energy efficiency was 2.15 kWh per mile over 399,663 miles of use.
  • The average battery pack SOC is 75.4%, indicating a possibility for a usage window shift.
  • The average runtime per day is 13.2 hours with an average of 13 charges per day. Each charge averages 20 kWh energy delivered.
  • Accessory loads contribute to the overall range capability, as more than 50% of “system on” time is spent at a speed of 0 mph where lighting and HVAC loads are still required.

image

And an excerpt from the analysis:

Advanced technology demonstrations typically experience challenges and issues that need to be resolved. The challenges and lessons learned from the demonstration included bus-related problems as well as programmatic issues. One major challenge is addressing demand charges and time of use charges that affect electricity cost. This will be a major challenge for any fleet looking to deploy electric buses that charge during peak times.

The industry needs to work on a permanent solution for all BEB (battery electric bus) adopters to keep costs reasonable in the future. Another challenge is training operators and maintenance staff in the differences between BEBs and conventional buses. Foothill reports that there is still a lot of learning as the agency ramps up to a larger BEB fleet. The team needs to understand how service can transition to a higher number of buses.

A second report is expected to be released by NREL later this year, following the conclusion of another year of in-service performance evaluation

 
Appreciate CleanTechnica’s originality and cleantech news coverage? Consider becoming a CleanTechnica Member, Supporter, Technician, or Ambassador — or a patron on Patreon.
 

Don't want to miss a cleantech story? Sign up for daily news updates from CleanTechnica on email. Or follow us on Google News!
 

Have a tip for CleanTechnica, want to advertise, or want to suggest a guest for our CleanTech Talk podcast? Contact us here.
Advertisement
 
Written By

James Ayre's background is predominantly in geopolitics and history, but he has an obsessive interest in pretty much everything. After an early life spent in the Imperial Free City of Dortmund, James followed the river Ruhr to Cofbuokheim, where he attended the University of Astnide. And where he also briefly considered entering the coal mining business. He currently writes for a living, on a broad variety of subjects, ranging from science, to politics, to military history, to renewable energy.

Comments

You May Also Like

Clean Transport

Electric school buses are experiencing rapid growth in the United States, with a nearly 10-fold increase in commitments by school districts and fleet operators in the...

Clean Transport

Electric buses are great for municipalities. They are cheaper to operate and maintain than diesel buses, and they emit no pollutants. For passengers, they’re...

Clean Transport

Federal purchase incentives included in the Inflation Reduction Act could lower the cost of heavy duty electric trucks by $40,000.

Clean Transport

Electric school buses are a growing topic of discussion in the transportation industry. To help inform schools about electric school buses, the U.S. Department...

Copyright © 2021 CleanTechnica. The content produced by this site is for entertainment purposes only. Opinions and comments published on this site may not be sanctioned by and do not necessarily represent the views of CleanTechnica, its owners, sponsors, affiliates, or subsidiaries.