- Plug-in electric vehicles (PEVs) grew from 9,241 in 2004 to 1,095,753 in 2024, a nearly 119-fold increase and by far the fastest-growing alternative-fuel category tracked.
- 2023 was the crossover year: PEVs overtook E85 flex-fuel vehicles to become the single largest alternative-fuel category, and by 2024 outnumbered E85 by more than 2 to 1 (1,095,753 vs. 511,781).
- PEVs made up just 4.5% of tracked alternative fuel vehicles in 2004; by 2024 they were 51.1%, more than half.
- Conventional (non-plug-in) hybrids grew a more modest 19.4-fold over the same period, while CNG and propane vehicle counts grew far more slowly, at under 2-fold each.
01 Introduction: What This Data Covers
Plug-in electric vehicles grew nearly 119-fold between 2004 and 2024 in the U.S. Department of Energy's Clean Cities and Communities vehicle inventory (from 9,241 vehicles to 1,095,753) and in 2023 overtook E85 flex-fuel vehicles to become the single largest alternative-fuel category tracked. The figures come from Clean Cities and Communities partnership annual activity reports, which gives a year-by-year record of alternative fuel vehicles by fuel type from 2004 to 2024.
DOE Clean Cities and Communities, Alternative Fuel Vehicle Inventory, 2004–2024This is a fleet-reporting inventory, not a full census of every alternative fuel vehicle registered in the country; see Section 05 for exactly what that distinction means for how to read these numbers. Within that scope, though, two full decades of consistent annual reporting make it possible to see which fuel categories actually took hold and which stalled, well before that shift showed up in national vehicle-registration statistics.
02 Total Alternative Fuel Vehicle Growth
The total number of alternative fuel vehicles tracked across all categories grew from 207,098 in 2004 to 2,142,273 in 2024, a roughly 10.3-fold increase over two decades. But that total obscures a much bigger story underneath: which categories actually drove the growth changed completely over that span.
DOE Clean Cities and Communities, Alternative Fuel Vehicle Inventory, "Total" row, 2004 and 2024| Year | E85 | HEV | PEV | CNG | Propane | Total (All Types) |
|---|---|---|---|---|---|---|
| 2004 | 47,643 | 10,674 | 9,241 | 76,257 | 31,338 | 207,098 |
| 2009 | 642,520 | 107,585 | 4,568 | 44,317 | 7,937 | 811,853 |
| 2014 | 275,508 | 82,834 | 65,042 | 68,479 | 17,404 | 643,161 |
| 2019 | 275,216 | 144,875 | 263,543 | 100,938 | 31,985 | 1,003,562 |
| 2022 | 568,837 | 154,089 | 475,330 | 123,463 | 33,716 | 1,552,928 |
| 2023 | 534,976 | 157,582 | 595,912 | 129,026 | 33,909 | 1,692,743 |
| 2024 | 511,781 | 207,358 | 1,095,753 | 143,905 | 33,763 | 2,142,273 |
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Use the Calculator03 The Rise of Plug-In Electric Vehicles
No category in this dataset changed position as dramatically as PEVs. In 2004, plug-in electric vehicles were a rounding error: 9,241 vehicles, just 4.5% of the total AFV inventory, smaller than the E85, hybrid, biodiesel, CNG and propane categories that year (hydrogen, LNG, renewable natural gas and renewable diesel were smaller still). Two decades later, PEVs are 1,095,753 vehicles and 51.1% of the total, more than half of every alternative fuel vehicle in the inventory, combined.
Calculated: 9,241 ÷ 207,098 = 4.5% (2004); 1,095,753 ÷ 2,142,273 = 51.1% (2024), from the DOE Clean Cities and Communities datasetThe specific year this crossover happened is identifiable directly from the data: in 2022, E85 vehicles (568,837) still outnumbered PEVs (475,330). By 2023, PEVs (595,912) had overtaken E85 (534,976) for the first time. One year later, in 2024, PEVs (1,095,753) outnumbered E85 (511,781) by more than 2 to 1. The gap didn't just open; it widened sharply in a single year.
DOE Clean Cities and Communities, Alternative Fuel Vehicle Inventory, year-over-year comparison of E85 and PEV rows, 2022–202404 Category by Category: Winners and Laggards
Outside of PEVs, the other categories in this dataset tell very different stories. Conventional (non-plug-in) hybrid vehicles grew steadily but far more slowly than PEVs: a 19.4-fold increase from 10,674 in 2004 to 207,358 in 2024, without a single category-defining crossover moment.
Calculated: 207,358 ÷ 10,674 = 19.4x, from the DOE Clean Cities and Communities dataset, HEV row, 2004 and 2024E85 flex-fuel vehicles, now the second-largest category, had a volatile history: after growing rapidly in the mid-to-late 2000s and peaking at 642,520 in 2009, the count fell by more than two-thirds to a low of 197,187 in 2012, before partially recovering into the 500,000s by the early 2020s. The dataset doesn't include a stated reason for that decline, so no cause is asserted here, but the swing itself is in the data.
DOE Clean Cities and Communities, Alternative Fuel Vehicle Inventory, E85 row, full 2004–2024 seriesCNG and propane vehicles, by contrast, grew the least of any tracked category: CNG rose 1.9-fold (76,257 to 143,905) and propane grew just 1.1-fold (31,338 to 33,763) over the full two decades, essentially flat compared to every other fuel type in this inventory.
Calculated: 143,905 ÷ 76,257 = 1.9x (CNG); 33,763 ÷ 31,338 = 1.1x (Propane), from the DOE Clean Cities and Communities dataset, 2004 and 202405 What This Data Does and Doesn't Represent
This dataset also does not distinguish battery-electric vehicles from plug-in hybrids within the PEV category, doesn't provide a state-by-state breakdown, and doesn't include vehicle age or how long each vehicle has remained in service. It answers one specific question well: among vehicles tracked through this DOE program, how has the mix of alternative fuel types shifted since 2004? For that question, the crossover of PEVs past E85 in 2023 is a real, directly observable finding in the data, not an estimate.
06 Data Sources
- U.S. Department of Energy: Clean Cities and Communities, Alternative Fuel Vehicle Inventory, annual data 2004–2024. cleancities.energy.gov