4 Lessons From a California Transit Authority’s Bus Electrification Rollout

The Antelope Valley Transit Authority (AVTA) plans to be the
first public transit agency in the United States to operate a 100
percent battery electric bus fleet.

Today AVTA operates 49 e-buses from Chinese bus manufacturer BYD
in Southern California, with 36 more e-buses to be delivered by the
end of 2020 allowing them to meet their zero-emission fleet target.
AVTA is also planning to install a microgrid at its bus depot.

WoodMac forecasts that electric drivetrains will grow from 3
percent to 9 percent of the annual bus market by 2025, with their
share increasing to 30 percent in the bus transit submarket.

As e-bus penetration rises, a new WoodMac
case study
outlines how AVTA’s e-bus transition and microgrid
journey illustrates four lessons that can inform other

1. Electricification done well can lead to significant

AVTA’s purchase of electric buses from BYD is forecast to cost
$78.6 million and be completed in 2022.

The purchase of e-buses made up most of the total
electrification costs, with charging infrastructure contributing an
estimated 15 percent.

Operational costs were also a key consideration in AVTA’s
e-bus electrification.

The agency projected that increased electricity consumption for
charging buses would be offset by savings from decreasing use of
diesel and maintenance for internal combustion engine.

When the agency completed the first million miles of electric
bus operation, they determined they had saved $500,000 compared to
operating diesel buses.

2. Depot charging alone may not be

AVTA expects that 80 percent of its e-bus charging will occur at
the bus depots. The agency has also deployed five wireless charging
stations along some bus routes to augment depot charging.

AVTA found that some routes would be benefit from additional
charging beyond the depot. Wireless charging was chosen at these
sites over pantograph charging, the other main form on on-route
charging, due to safety concerns.

So far, charging at the depot has been the most widespread form
of e-bus charging in the U.S., though on-route charging such as
overhead (pantograph) and wireless charging are becoming more

While depot charging is less expensive than on-route charging at
approximately $100,000/charger, depot charging requires the bus to
be plugged into the charger for hours at a time, complicating bus

3. Coordinated charging has a learning

The learning curve for managing charging was one of the biggest
hurdles AVTA faced in its fleet-electrification journey.

AVTA started out using spreadsheets to determine which buses
should be charged when. As its e-bus fleet grew, AVTA turned to an
outside supplier of integrated control and monitoring solutions for
transit to develop an e-bus load management system.

In general, if the grid that serves a bus depot cannot
physically support the increased electric demand for charging
buses, upgrades to substations and distribution lines will be
required. This can drastically impact a project’s economics.

For example, AVTA found that it cannot simultaneously charge 90
buses given the current grid infrastructure in its jurisdiction. As
a result, they developed a charging protocol to charge buses in
waves based on variables such as each bus’ state of charge and
route optimization, allowing for the complete electrification of
the fleet while operating within the constraints of the grid.

Situations like this present a clear opportunity for utilities
to provide insight into the capacity of the grid and strategies to
coordinate charging infrastructure within those constraints.

4. Microgrids can provide additional

Of 202 transit agencies in the US that have e-buses, AVTA is one
of only seven that is planning a microgrid. The agency is
integrating this solution to achieve cost savings, resilience and
sustainability goals.

AVTA released a request for proposals for solar and storage
systems that would cover its extra electricity needs stemming from
e-bus charging. The selected energy partner will own the solar and
behind-the-meter storage assets and sell the energy to AVTA via a
25-year contract with a guaranteed savings.

AVTA followed a similar pattern to other transit agencies:
Microgrids and other distributed energy resources are not often
considered until after transit authority has gained experience with
its first electric buses. Microgrid players may want to begin
conversations with agencies during this key window after their
first e-bus purchases, when potential customers are likely to be
most open to learning about solutions.

As e-buses claim a larger share of U.S. bus sales, the
opportunity around fleet electrification grows. Fleet operators,
utilities and microgrid developers are just beginning to explore
the opportunities and benefits at the nexus of e-buses and
distributed energy resources.


The full insight, Electric
bus charging infrastructure and microgrids: A grid edge case
, is available for purchase from Wood Mackenzie. It
includes the full AVTA case study, a snapshot of e-bus and e-bus
charger manufacturers in North America, overview of primary
charging technologies for e-buses, an overview of the six agencies
planning microgrids for their e-bus fleets, and more.

Kelly McCoy is an electric vehicle analyst at Wood Mackenzie.
Isaac-Maze Rothstein is a microgrid analyst.

Source: FS – GreenTech Media
4 Lessons From a California Transit Authority’s Bus Electrification Rollout