Exponential adoption of battery electric cars

Abstract

The adoption of battery electric vehicles (BEVs) may significantly reduce greenhouse gas emissions caused by road transport. However, there is wide disagreement as to how soon battery electric vehicles will play a major role in overall transportation. Focusing on battery electric passenger cars, we analyze BEV adoption across 17 individual countries, Europe, and the World, and consistently find exponential growth trends. Modeling-based estimates of future adoption given past trends suggest system-wide adoption substantially faster than typical economic analyses have proposed so far. For instance, we estimate the majority of passenger cars in Europe to be electric by about 2031. Within regions, the predicted times of mass adoption are largely insensitive to model details. Despite significant differences in current electric fleet sizes across regions, their growth rates consistently indicate fast doubling times of approximately 15 months, hinting at radical economic and infrastructural consequences in the near future.

Fig 1. Global exponential growth of BEC adoption.

The number of battery electric cars in operation has grown rapidly across the world. The straight-line increase on the logarithmic-linear scale (inset) over two orders of magnitude (black line indicates slope of fit of 2016-2022 data) highlights that the recent adoption has happened exponentially.

Fig 2. BEC adoption growth across regions.

The BEC share in the total PC fleet has grown significantly over the past decade, with individual countries being at very different stages of adoption: In 2022, Norway features a BEC share of 25.3% (out of frame), while Poland is at just under 0.2%. Europe outperforms both the USA and the world average.

Fig 3. Estimating BEC dominance.

Battery electric car fleet sizes may soon dominate the total passenger car fleet, shown here for Germany as an example. The past total passenger car fleet size stayed approximately constant (black horizontal line), with the data points (black squares) taken from the Eurostat dataset. The exponential (gray, Eq (2)), logistic (brown, Eq (5)) and Bass diffusion (red, Eq (8)) models predict the future growth of BEC adoption. The dominance times t_1/2 (gray, brown, red vertical lines) at which half of the passenger car fleet (dotted horizontal line) consists of BECs are estimated to occur between 2027 and 2032, depending on the model.

Fig 4. Model-estimated BEC adoption trajectories.

The speed of BEC adoption varies strongly across countries (thin orange lines denote individual European countries) in both the logistic model (A) and the Bass model (B). Norway, Sweden, and the Netherlands exhibit the fastest adoption, Spain, Portugal, Italy, and Greece the slowest. Overall, the models predict rapid dominance of BECs (more than 50% of the PC fleet, horizontal gray line) in Europe, the USA and globally shortly after 2030.

Fig 5. BEC dominance time estimates.

Battery electric cars start to dominate the passenger car fleet in European countries between 2024 and 2039, according to our models. The ranking of the estimated dominance times of the countries is consistent across the three models, with the exponential model giving the earliest time, the logistic model an intermediate time, and the Bass diffusion model yielding the latest time. The dominance time estimates for the USA and the aggregate regions “Europe” and “World” are indicated by vertical lines, according to the logistic (solid lines) and Bass diffusion (dotted lines) models.

Fig 6. Stage and growth of BEC adoption across countries.

A: The current (2022) stage of BEC adoption strongly varies across individual countries, ranging from 0.18% in Poland to 25.3% in Norway (note the logarithmically-scaled abscissa). B: All countries exhibit similarly large growth rates near the average of $\overline{a}=0.55/\text{yr}$ (solid vertical line), yielding a standard deviation of σ_a = 0.09/yr (dotted vertical lines).