San Jose Unified School District near San Francisco is the first to use renewable diesel to power its yellow fleet. Lead Mechanic Andew DeBolt fuels one of the district’s Type A school buses.
“Alternative fuels offer a nice, clean, safe option for our chil-
dren,” says Van Harpen. “Compressed natural gas and propane are actually safer than diesel because they are more difficult to ignite.” While diesel is embraced as the most efficient fuel for all school bus types, its ignition point is also the lowest at about 500 degrees. Te Iowa bus fire last month could suddenly prompt more ques- tions about safety, especially in older models. However, the igni- tion point is around 851 degrees for propane and 1,100 degrees for CNG. Also, both of these fuels need the right fuel-to-air ratio for ignition. In addition, propane and CNG buses are equipped with automatic shut-off features, where all the fuel flows back into the tank when the engine is shut down. Van Harpen said there is no “one size fits all” solution. Instead, choosing an alternative fuel depends on many factors. “For in- stance, with an electric bus, the range is 75 to 100 miles, depend- ing on the terrain, but also on the driving style,” she explained. “If the driver slams the pedal down, it uses more energy. Propane or compressed natural gas might be a better choice. Also, the district must take into consideration whether they are urban or rural, and
what fuel is available. Blue Bird has an alternative fuel team that goes out and advises districts on the infrastructure, safety, and the total cost of ownership. With the VW Mitigation Funds, it is easier to get alternative fuel buses.” While today’s diesel school buses are 90-percent cleaner than a decade ago and exceed EPA requirements for greenhouse gas emissions, a new type of diesel is now available. San Jose Unified School District near San Francisco chose renewable diesel, which is different from biodiesel because the former meets ASTM specifica- tions for diesel and requires no blending. “While biodiesel is made from vegetable oil or animal fat,
renewable biodiesel is taken a step further in the refining process. It is refined like fuel would be, to break down and get rid of all the excess stuff that is in the biodiesel,” said Andrew DeBolt, lead equipment mechanic at San Jose Unified. “Tere is no difference at all in how the bus operates. We didn’t exactly advertise to our drivers that we were switching, and they couldn’t tell the differ- ence. Te price is about the same. If diesel goes up, renewable goes up just because it can, but generally, we pay the same, sometimes
www.stnonline.com 41
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52
