Electric School Buses

We have purchased two electric buses and each bus cost $382,786. 

A diesel bus currently costs $165,990.

Our electric buses are paid for by the Transportation Vehicle Fund, which is a combination of depreciation dollars paid by the state and levy dollars approved by Mercer Island voters. (The last Transportation Levy was approved in 2017.)

We will continue to collect depreciation dollars for the buses that we own to finish their depreciation cycles. Big buses are depreciated over a 13-year period and small buses are depreciated over nine years. We are looking at the logistics of a future Transportation Levy to address any shortfalls in our Transportation Budget.  

100 miles when fully-charged.  

With a Level 2 (240 volt) charging station located in the bus yard. We have two Level 2 charging stations (which take between 8-10 hours to fully charge the bus).  With the level 2 charging stations we expect the batteries to achieve about 80% of their maximum capacity on cold winter days. The optimal charging temperature (which is not the ambient temperature, but the temperature of the batteries, which have an independent heating/cooling system) is between 60-80°F.

About $15,000 for a pair of Level 2 charging stations. Our bus yard is ready for up to 5 Level 2 charging stations. When we are ready to expand beyond that and/or when we want to install a DC fast charging station, we’ll need a significant infrastructure investment from the district and the surrounding Puget Sound Energy lines.

Fourteen. Two banks of 7 XALT Energy Lithium-Ion batteries.  Each battery weighs about 140 pounds.

The batteries are expected to reach 80% of their charge after 12 years. The depreciation schedule for school buses from OSPI runs 13 years. (This is how long the state continues to pay you for having a vehicle in your fleet. Most districts replace most vehicles at the end of that depreciation period.)
 

They should be approximately 80% less than the operations and maintenance costs of an equivalent diesel. The electric bus motors have about 20 moving parts. The equivalent diesel motor has about 2000 moving parts.

Yes. A electric bus runs at about 60 dB compared to about 85 dB for a diesel bus. It’s the difference between quiet background music and a very noisy restaurant atmosphere. The bus is so quiet that it has a special artificial noise-maker which kicks in below 23 miles an hour so that pedestrians aren’t surprised by its approach.

Because electric buses are quieter, we are encouraging families to download the BusQuest App to track when their bus is arriving at their stop because they can't hear their their bus coming if the electric bus is on their route.
 

A little bit. Mostly having to do with the acceleration and the deceleration of the bus. To maximize battery charge, it is beneficial to let the bus slow by coasting. This regenerates some lost charge to the batteries. The electric bus is also capable of much faster accelerations than a diesel engine (which is not an efficient use of its batteries); but is something that drivers must adjust to.   
 

TBD.  Most likely routes to be considered will be ones that run about 25 - 30 miles/day (which are middle length routes for the district).  The considerations are to stay well within the vehicle’s range while also maximizing the value of having a cleaner, quieter bus. Likely possibilities would be routes servicing the Town Center (where there is already a lot of noise and air pollution) or Islander Middle School (where there are a large number of buses each day).
 

No.

Electric vehicles have a number of immediate local advantages in reducing dangerous particulate air pollution and in reducing noise pollution.  In the bigger picture, converting to an all electric fleet is important to reducing the impact of global warming and aligning our actions with our ideals.

Up to 84 (little kids, 3 to a bench seat); 56 bigger students (2 to a bench seat)

Only when operated by our drivers and only for community and school functions. Publicly funded school buses are not licensed for private commercial service.

Mercer Island School Bus drivers need to have Class B or higher Commercial Drivers’ Licenses with Passenger and School endorsements and the Air Brake-Restriction removed.  In addition, drivers of the electric bus must pass an hour-long online course covering specific safety and driving concerns for electric buses, as well as a similar amount of behind the wheel time familiarizing themselves with handling the electric buses. If you want to drive an electric bus, check out our employment page.  We provide training.

This will depend a lot on how the batteries, the market, and recycling develops over the next decade. But there is a good chance that the batteries will be removed from the bus and converted into stationary storage (that is, battery backup) for district buildings, while the bus itself will be recycled or refurbished for further use.