A new study conducted at the Lawrence Berkeley National Laboratory (Berkeley Lab) in California suggests using electric vehicles (EVs) as mobile devices for storing energy from renewable sources, thereby eliminating the need for building expensive stationary facilities.
Specifically, the study looked at the consequences of deploying renewables across the energy grid on a large scale in the state of California, as well as the associated problems of variability and using EVs to mitigate them.
According to lead author Jonathan Coignard, “California has ambitious targets to decarbonise transportation, mandating the introduction of 1.5 million zero-emission vehicles (or ZEVs) by 2025, most of which will be EVs. It also has a renewable energy policy requiring 33 percent of grid energy to come from renewables by 2020, and 50 percent by 2030”.
Using electric vehicles from the ZEV Mandate as energy storage units could prove beneficial in efforts to integrate renewable energy into the grid by lowering capital costs.
Needless to say, employing EVs in this manner could also go a long way in decarbonising transportation not only in California, but also around the world – at least once the generation of renewables gains enough traction.
In the study, researchers looked at three scenarios in terms of how growing numbers of EVs would affect the evolving grid load: 1) if the charging of EVs was not subject to any controls; 2) if vehicles were grid-integrated with controllable charging only (one-way power flow, or V1G); and 3) if vehicles were grid-integrated with controllable charging and discharging rates (two-way power flow, or V2G) for the worst day of each forecast year.
Results showed that California’s Storage Mandate could largely be met through its EV deployment target and with only one-way charging control of EVs without compromising the mobility needs of drivers.
“Even more significantly, we found that several billion dollars of capital investment could be saved if EVs are used in lieu of stationary storage. Those savings could be redirected to further accelerate the deployment of clean vehicles and vehicle-grid integration, and could even be used to pay EV owner when their vehicles are grid-connected with controlled charging,” said co-author Dr Samveg Saxena.