Wendell study: about half of Eden's routes feasible with today's electric buses; infrastructure and costs remain major hurdles

A NYSERDA-funded study presented to the Eden Central School District by Wendell engineers found that 56% of the district's 25 bus routes could be completed with current battery-electric school buses, while 11 routes could not be supported by market vehicles today.

"We evaluated 25 different route buses, and of those 25, it looked like 56% of those could be completed with an electric school bus of today's market and 11 of them could not be completed," Katie Ekholm, project manager for Wendell, said during the Oct. 20 board meeting. The team modeled worst-case winter conditions, including full passenger loads, cold temperatures and battery degradation, to be conservative.

The study modeled energy use hour-by-hour for a worst-case January day and estimated a peak district-side charging demand of about 823 KVA for converted buses and about 855 KVA including vans and SUVs used for student transport. Wendell recommended a new 480-volt, three-phase service fed from a utility-owned transformer (proposed at 1,500 KVA) and a new 3,000-amp main feeding multiple switchboards.

"We determined that the peak demand... would be about 823, and the peak demand of all of those buses as well as any type of vans or SUVs that transport students... would be about 855 KVA," Ekholm said.

Wendell also reported manufacturer constraints: the district's preferred maker, Thomas, lacks larger battery options for some vehicles, forcing either mixed manufacturers or delaying replacement of those routes until larger models become available. For several Type A and Type C routes, the required battery capacity currently exceeds the largest models Thomas offers, so Wendell proposed carrying those buses forward in plans with conservative cost estimates.

Phasing and cost estimates for district-side charging infrastructure were summarized in three phases: Phase 1 (2028'2030) proposed about 11 chargers and new service with fire protection (Wendell cited approximately $3.6 million for Phase 1), Phase 2 (2031'2032) about seven chargers (~$1.5 million), and Phase 3 (2033'2035) about 12 chargers (~$2.2 million). Wendell gave a customer-side total of about $7.3 million including fire protection and $5.9 million without.

National Grid reviewed the study's anticipated load and said the local feeder and substation could accommodate the proposed peak load, but Wendell cautioned that in other districts National Grid has indicated the need for major substation or feeder upgrades.

Board members pressed the consultants on operational impacts for sports and long midday runs, heavier vehicle weights (Wendell estimated about 5,000 pounds more per electric bus in some cases), and the effect of long lead times for switchgear (Wendell cited current lead times around 15'16 months). Wendell recommended a pilot ("phase 0.1")—installing one to three chargers on existing service to test capacity and avoid long utility design lead times while qualifying the district for state voucher programs.

The district will use the study to pursue vouchers and incentives and to inform next steps, including possible pilot purchases and a work request to National Grid if the board elects to begin Phase 1 design.

Sources in the meeting: Wendell project leads John Hevrilla and Katie Ekholm; references in the presentation to NYSERDA and National Grid.