Electric vehicle batteries could be harnessed to provide all the battery storage capacity necessary to stabilize renewable-based electricity grids worldwide in the coming decades, according to a new study.
EVs are often thought of as a potential source of stress on the electric grid—for example, if everyone charges their vehicle at the same time. The new findings flip that script and cast EVs as a solution rather than a further complication to decarbonization challenges.
The study is not the first to investigate using EV batteries to help even out the availability of power from variable sources of renewable energy such as solar and wind. But the new study is more comprehensive than past efforts, taking into account a larger slate of variables that could affect how much battery capacity is actually available in practice.
Researchers combined three different models to calculate how much EV battery capacity will be available for grid storage in the coming years out to 2050: a model of how many EV batteries will exist (depending on things like how fast the vehicle fleet goes electric and how battery technology develops); a model of EV driving and charging behavior (after all, EVs cannot provide backup storage to the grid when they are being driven); and a model of how batteries’ capacity to hold a charge degrades over time.
In theory, EV batteries could store extra electricity for a few hours either when they are installed in a car that is hooked up to the grid, or after they are retired. That is, even when their capacity to hold a charge has fallen to the point where they are no longer practical to use in a vehicle, they can still be useful as part of stationary storage banks.
Between these two approaches, 32 to 62 terawatt-hours (TWh) of EV battery storage could be available to help stabilize the grid by 2050, the researchers report in the journal Nature Communications.
Past estimates of demand for short-term grid storage run from 3.4 to 19.2 TWh, with an average of 10 TWh. In other words, EV batteries alone would be more than capable of handling grid storage needs.
But how much EV battery storage capacity is likely to be available in the real world? This depends on additional factors like what proportion of EV owners participate in vehicle-to-grid storage programs, what proportion of retired batteries are used for grid storage, and so on.
Only 12-43% of EV owners would need to participate in grid storage programs to meet all short-term storage demand globally, the researchers calculated. If half of retired EV batteries were used for grid storage, only 10% of owners would need to participate.
“Short-term grid storage demand could be met as early as 2030 across most regions,” the researchers write.
What’s more, they add, “Our estimates are generally conservative and offer a lower bound of future opportunities.” But taking advantage of those opportunities will require a range of policy and technological innovations, such as incentives to encourage EV owners to participate in vehicle-to-grid programs; regulations to require commercial fleets to connect when not in use; and hardware and software to facilitate participation.
Source: Xu C. et al. “Electric vehicle batteries alone could satisfy short-term grid storage demand by as early as 2030.” Nature Communications 2023.
Image: ©Anthropocene Magazine.