VEHICLE-TO-GRID
with Con Edison in New York State, fi tting
bidirectional chargers to electric school buses.
These are parked 97% of the time and they
off er a combined 75kW output during the
summer, which reduces the seasonal demand
spikes from air-conditioning.
“If there’s one thing that
utilities agree on, it’s that the
school bus is the killer application
of V2G. There’s a signifi cant
upfront cost for buses for
installation and integration
into the grid. If you can fi nance
it in the long run by using those
“Deployment relies on fl eets sharing
sensitive information about their
operations with project partners”
Dr Doros Nicolaides, senior consultant ULEV & energy, Transport Research Laboratory
vehicles to provide grid services, that
will generate some revenue and pay
for the cost of integration,”
Poilasne adds.
However, Dr Doros Nicolaides,
senior consultant ULEV & energy
at the UK-based Transport
Research Laboratory, adds that
company policy could be as big a
restriction as today’s incompatibility
issues between back-o ce systems.
“Deployment relies on fl eets sharing
sensitive information about their operations
with project partners, which can be a
signifi cant barrier,” he claims.
Power to the people
It’s yet another giant leap for end-users as
Hugo Herrmann, V2G development engineer
IS WEAR AN ISSUE?
The potential downside
of over-using bidirectional
charging is an increase
in the number of chargedischarge
cycles the cells
are put through. A recent
Lawrence Berkekey National
Laboratory report suggests
this could reduce battery
life by 10%, warning that
it should only be called on
when it’s absolutely needed.
However, the underlying
technology – which enables
remote monitoring of battery
status – could allow much
finer control, as Cenex’s
Chris Rimmer explains:
“Vehicle-to-grid potentially
unlocks the ability to manage
the batteries a little more
effectively, which improves
their lifetime performance
and comes through in total
cost of ownership. I think
the jury’s out on that last
point, but that would be
a further push.”
Ricardo’s Julian Dunn
agrees, adding that the
typical 10kW output is a
relatively light load on the
battery. “There could be
limits around what state
of charge you enable and
how much power you could
deliver each way,” he says.
“Ultra-fast charging is likely
to have a greater impact on
battery degradation than
modest V2G functionality.”
www.electrichybridvehicletechnology.com // January 2020 // 81
roll-out costs, because the
hardware is within the vehicle.”
Vincent Schachter, head of
global energy services at Enel X
e-Mobility, which is providing V2G
units for projects worldwide, says
the industry needs a standardized
approach: “The development of
V2G-compatible EVs has been
slowed by a lack of communication
standards for bidirectional
charging, but emerging standards
are expected to greatly impact
scale and cost reduction.
“For a taste of things to come,
we can compare this technology to solar power
generation or stationary storage. In both
cases, once an infl exion point was reached
in the technology maturation and adoption
curve, industrial scale and cost
reduction happened quickly.”
Incompatibility isn’t an
insurmountable problem as
Nuvve has been working with
OEMs on ways to share state-ofcharge
information via vehicle
telematics systems, and Poilasne
says pilot projects show the business
case already exists. These have shown
V2G can reduce EV ownership costs by
around 25%, but that fl eets are likelier to
be earlier adopters due to consumers’ less
predictable usage patterns.
Even businesses aren’t entirely reliable.
During a fi eld trial in Norway, Nuvve found
users wouldn’t always return vans to the depot,
aff ecting the power available for the grid. By
comparison, the company is working on a trial
5. Nuuve has worked
with Nissan on its fi rst
V2G hub in Denmark
6. Nuuve has also
worked to give school
buses in California
bidirectional charging
5
6
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