$25. 002009 ieee 52 ieee

Impact of Plug-in Hybrid Electric 

Vehicles on the Distribution Grid

PHEVs show great promise; they have the potential to curb 

emissions and reduce the cost of transportation. Although 

wide-scale adoption of plug-in vehicles is still a few years 

away, politicians, electric utilities, and auto companies are 

eagerly awaiting the opportunities that may arise from re-

duced emissions and gasoline consumption, new services 

and increased revenues, and new markets that would create 

new jobs. This is particularly true for electric utility com-

panies, which could see substantial revenue growth through 

the electrifi cation of the transportation market segment. For 

consumers, plug-in vehicles will signifi cantly lower opera-

tional  costs  when  compared  with  traditional  gasoline  cars 

or today’s gasoline-electric hybrids. The savings are poten-

tially huge, as electricity costs per mile work out to about 

one-quarter to one-third the cost of gasoline, depending on 

the region and price of gasoline. 

A Pacifi c Northwest National Laboratory (PNNL) study 

states that the existing generation, transmission, and  distribution 

system in the United States, if optimally utilized at all hours of 

the day, could provide enough power for  plug-in vehicles to 

replace up to 73% of the nation’s cars, vans, SUVs, or so-called 

figure 2.

 Wind turbine power curve.

Typical Output of Wind Turbine Versus Wind Speed

120%

100%

80%

60%

40%

20%

0%

0

2

4

6

8

10

12

14

16

18

Wind Speed (m/s)

Typical Operation

Power Output (%)

Cutoff

Fast Ramp

20

22

24

26

28

30

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