IEEE Electrification - June 2019 - 44

Unmanaged
Charging

Smart
Charging (V1G)

V2G

V2G With AS

Real Levelized Cost (US$/Yr/EV)

600

400

200

US$313

US$243
-US$94

-200
-US$248
-400

Costs
Net
and
Value
Benefits

CO2 Cost System Energy Cost
Net Benefit Net Cost ASs
RPS Cost
Distribution Capacity Transmission Capacity Generation Capacity
Figure 4. The levelized costs and benefits for the base scenario under the utility's control. CO2: carbon dioxide.

assume that 2018 is the resource balance year, giving
values of US$124/kW-yr in 2018 and increasing to
US$144/kW-yr in 2030. Given recent approvals by the
CPUC for energy storage projects, it is possible that,
in the near future, a zero-emissions resource such as
battery energy storage may be a more appropriate reference resource with a much greater avoided cost for
generation capacity.
Although distribution network capacity can be very valuable, the value is very location specific, and the opportunities
to defer distribution upgrades with DERs can be limited.
Based on an analysis of distribution avoided costs filed with
the CPUC, we chose distribution capacity values of US$20/
kW-yr and US$120/kW-yr for the base and high-value scenarios, respectively, with the high-value scenario representing a capacity-constrained area in Southern California.

V2G Delivers Value Over V1G
Our modeling indicates that V2G technology can transform
an EV from a load the utility incurs a cost to serve into a
DER that creates significant benefits. The total cost/benefit
and the avoided cost component value streams are shown
for several VGI use cases in Figures 4 and 5 for the base and
high-value scenarios, respectively. These figures suggest the
costs for and benefits to the utility from serving and managing a group of five EVs in different use cases on a levelized per-vehicle, per-year basis. Generation capacity,
distribution capacity, and AS are the most significant value
streams captured.
When AS is not provided, there is an energy value
stream benefit; however, when AS is provided, energy

I E E E E l e c t r i f i cati o n M agaz ine / J UN E 2019

costs are incurred to enable greater participation in AS
markets. In the high-value scenario, the ability to provide
AS adds little benefit over load shifting with V2G. We also
studied a sensitivity case in the high-value scenario,
where the model's constraints and penalties for reducing battery degradation are removed. In that case, the
total benefit rose by US$359/vehicle/yr along with the
annual energy discharged, from 10,225 kWh/vehicle/yr
to 15,051 kWh/vehicle/yr.
The incremental values of V1G and V2G technologies
are shown in Table 1 for the different scenarios and use
cases. The table also includes the annual energy discharged per vehicle with V2G.

Realizing the Value of V2G
The results of our modeling indicate that it will be most
advantageous to deploy V2G technology in generation and
distribution capacity-constrained locations, where the
value of V2G can be more than four times that of V1G. If
energy storage becomes the preferred generation capacity
resource, then all of the dollar values presented in Table 1
will be even greater. When automakers design V2G systems
as a feature on vehicles, they must be convinced that any
additional battery wear and tear will be outweighed by the
V2G benefits for the vehicle owner. Our modeling shows
that relaxing the limits on discharging the battery would
increase the electric grid value of V2G by 32%, although the
energy discharged would also increase by 47%.
There are challenges that must be overcome before consumers can access the large potential value streams of distribution capacity and AS. There may be only a few locations

IEEE Electrification - June 2019

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