Electric buses cost less to maintain than diesel in every United States transit fleet studied

Every fleet measured spent less to maintain its electric buses

Four national laboratory evaluations, done for the Federal Transit Administration, tracked what United States transit agencies spent keeping battery electric buses running against the diesel, gas or hybrid buses on the same routes. Maintenance cost per mile, the bill spread across every mile driven, came out lower for electric buses in every agency found here. King County Metro in Seattle spent 0.18 dollars a mile on electric buses from April to November 2016, against 0.44 dollars for diesel. County Connection, in Concord, California, spent 0.39 dollars a mile on electric buses from February 2017 to May 2018, against 0.44 dollars for diesel. At Clemson Area Transit in Seneca, South Carolina, the gap ran widest, 0.55 dollars a mile for electric against 1.53 dollars for diesel over 2014 to 2018, meaning diesel cost 2.78 times as much to maintain, a MAOWCE calculation from those 2 figures.

One thing I explain to people is that with electric buses, it's not taking a hammer to it, it's taking a laptop, and just doing a different program.

Keith Moody, general manager, Clemson Area Transit. Source 5.

The one bad number came from bad luck, not bad batteries

A comparison built by the Texas A and M Transportation Institute lines up 4 agencies on the same measurement. 3 held maintenance costs under 0.40 dollars a mile. The 4th, Dallas Area Rapid Transit, spent 1.82 dollars a mile, more than 4 times its nearest peer. The institute traced the spike to 1 bus needing 3 expensive repairs to its motor inverters, the electronics that turn battery power into motion, during a study window covering only 45,020 miles, far less driving than the other 3 agencies logged.

Fuel costs turn on the electricity rate, not the bus

Maintenance savings held everywhere. Fuel costs did not. At County Connection, electricity cost 0.73 dollars a mile against 0.40 dollars for diesel, because the agency paid 0.22 dollars for every kilowatt hour, the standard unit electricity is billed in, more than most agencies here paid. Its buses were not less efficient, they simply charged on a costlier rate. At King County Metro, electricity cost 0.50 dollars a mile against 0.29 dollars for diesel. At Foothill Transit in Los Angeles County, electricity cost 0.41 dollars a mile against 0.25 dollars for compressed natural gas, a fuel some agencies burn instead of diesel, though the evaluators at Foothill Transit caution the comparison is not fair, since the electric buses ran a slower, more stop heavy route. On the identical route, a separate test found the electric buses reached more than 8 times the fuel economy of the gas buses.

Buying one still costs more, and the gap is not fixed

Frontier Group and the U.S. PIRG Education Fund put an average diesel transit bus at 500,000 dollars against 750,000 dollars for an average electric one, a gap of 250,000 dollars. A separate national survey of transit agencies, done for the Transportation Research Board, put the average electric bus closer to 900,000 dollars. What agencies actually paid varied widely. Worcester Regional Transit Authority in Massachusetts paid 1,000,000 dollars each for 6 Proterra buses in 2013, the highest price in this research. IndyGo in Indianapolis paid the least, 579,000 dollars each, but those were diesel buses converted to electric, not new vehicles built electric from the start.

What one agency reports saving on its own

Chicago Transit Authority told the U.S. PIRG Education Fund its electric buses, bought in 2014, save more than 24,000 dollars a year in fuel and 30,000 dollars a year in maintenance against diesel buses bought the same year. That is the agency describing its own fleet, with no independent check on it in this research, unlike the 4 evaluations above.