From a market perspective that particularly regards the
type of services the V2G can provide, the characterization
mainly depends on the V2G infrastructure being either unidirectional
or bidirectional. Unidirectional V2G can sell demand
response services by throttling EVs charge rate only, being
therefore limited to participation in regulation or spinning reserve
market, whereas bidirectional V2G would be able to
provide electricity delivery to the grid as an additional service
[1]. It must be recalled in this respect that if the implementation
of unidirectional V2G sounds feasible and promising, on
the other hand the bidirectional solution still appears futuristic
because it requires additional hardware not included in the
EVs in production and it increases the battery degradation [7,
8].