King County Metro Transit (KCM) in Washington state has completed an accelerated durability and reliability test of the Proterra Catalyst 40' FC (fast charge) battery-electric bus. Simulating one year of continuous operation with a constant 97 passenger equivalent load, this was the most rigorous test of its nature yet performed in the industry.
Operating 24 hours per day over the 106-day period, the Proterra Catalyst vehicle achieved 32,545 total miles—nearly twice the distance of standard industry tests at Altoona. The bus was hauling 14,500 lbs (6,577 kg) of water ballast during the entire test period, which represents 125% of a normal full load of 77 passengers with standees.
|Proterra electric transit bus. Source: KCM. Click to enlarge.|
The vehicle averaged 325 miles (523 km) each day, with a maximum mileage of 572 miles (921 km) in one day, and was charged more than 1,750 times during the test period.
From mid-October to the end of January 2016, the bus achieved 98% uptime. It was out of service for only 6 days, including 3 holidays, preventative maintenance checks summing to 1 day, and 2 days of quick maintenance to resolve minor issues. The vehicle experienced some basic wear and tear, but nothing out of the ordinary.
Average fuel economy was 15 MPGe over this testing period, 3.125-times more efficient than current KCM 40' diesel buses (4.8 MPG). This is projected to improve to 18 MPGe (3.75 x diesel) at normal loads. (Proterra Altoona test results yielded 22 MPGe.) KCM’s diesel-hybrid buses average 6.3 MPG.
Total estimated cost of maintenance for this test, incl. parts & labor was approximately $0.20/mile, compared to $0.90/mile for diesel; $1.10/mile for diesel hybrid; and $1.00/mile for CNG buses.
In February 2016, three Proterra Catalyst buses went into King County Metro revenue service.