Plug-in hybrid electric vehicles and battery electric vehicles don’t just have the potential to reduce emissions – they could also help meet the significant energy imbalances on the power grid that can be created by large amounts of wind generation.
A new report by researchers from the US Department of Energy’s Pacific Northwest National Laboratory looked at the potential for electrified vehicles to meet the entire additional energy imbalance that is imposed by adding 10GW of additional wind to the Northwest Power Pool. It looked at two scenarios – V2GHalf and V2GFull.
Under V2GHalf scenario, the charging is varied in an effort to absorb the additional imbalance from wind generation – but it is never fed back into the grid. This is desirable to carmakers that have concerns about battery warranty if vehicle-to-grid discharging is allowed.
On the flipside, V2GFull will not only vary the charging of the vehicle battery, but it will also vary the discharging of the battery pack into the power grid. This is less desirable to carmakers but could double the capacity of electric vehicles’ value to the grid.
Among the key findings of the report were that a V2GFull operating mode would have some market acceptance barriers to overcome whereas V2GHalf strategies only require a modulation of the charging current and so won’t violate the users’ desire to have the battery fully charged at a certain time. It also suggests there is a strong relationship between the availability of charging stations during the day and the total number of vehicles needed to meet the balancing requirements – there are diminishing returns after the vehicle stock is offered a certain amount of charging stations at work.
Overall, the report concludes that the electric vehicle fleet could make a significant contribution to meeting the new balancing requirements that are associated with grid integration and the degree of this will depend on the economics of implementation and a viable business model.
