Fleet electrification and low-carbon fuels by 2035 (ADEME)

Key findings from ADEME's 2020-2035 study: electrification versus thermal inertia

ADEME modelled three mobility pathways through 2035: a business-as-usual trend (REF), a territorial cooperation scenario with a 17% drop in mobility demand (S2), and a high-demand "recovery" scenario where a 28% increase is offset by massive electrification (S4). These pathways are cross-referenced with three charging profiles, ranging from grid-friendly to grid-straining.

Across all scenarios, the study confirms a net lifecycle benefit for electric vehicles: greenhouse gas emissions fall by 55% to 56% for passenger cars versus diesel, and by as much as 68% for heavy trucks. That result already accounts for the upfront carbon footprint of battery manufacturing, often cited as a drawback.

Even accounting for battery manufacturing, electric remains the most environmentally sound choice over the full lifecycle, for light vehicles and heavy trucks alike.

This finding validates the electrification path already under way in many fleets. But it says nothing about how quickly this benefit materialises at the scale of the entire vehicle fleet, nor about the infrastructure conditions required to get there without straining the grid.

The infrastructure wall: why charging behaviour matters

ADEME's study isolates a factor often underestimated: charging behaviour matters as much as the sheer number of electric vehicles on the road. Fast public charging, reliant on high-power stations, requires heavy reinforcement of distribution networks, estimated at up to 12% additional power lines.

By contrast, moderate daytime charging, aligned with solar production, proves far gentler on the grid. The catch is that this behaviour requires charging points to be available at workplaces or depots, plus a usage discipline that is hard to scale nationally.

Two charging profiles, two grid trajectories

• Fast public charging: heavy reliance on high-power stations, significant grid reinforcement
• Moderate overnight charging: home or depot-based, limited grid impact but uneven coverage
• Moderate daytime charging: the most grid-friendly, aligned with solar output, but the hardest to roll out at scale

For a fleet manager, this reframes the issue entirely: choosing a charging strategy is as strategic as choosing the vehicle itself. Poorly anticipated rollout can create local bottlenecks, even with high-performing vehicles.

Thermal fleet inertia: a challenge lasting until 2030-2035

Renewing a car or truck fleet takes time: thermal vehicles bought today will still be on the road for years. ADEME quantifies this in its high-demand scenario (S4): the environmental gains from electrification are entirely masked until 2030 by emissions from the residual thermal fleet.

In other words, even under the scenario most favourable to electric vehicles, the overall fleet's emissions curve only bends meaningfully after 2030. Until then, it is the thermal fleet on the road today that drives the real carbon footprint of road transport.

For a sustainability officer or fleet manager facing short and medium-term reduction targets, this inertia raises a concrete question: what should be done with thermal vehicles that will stay in service until 2030 or even 2035? Waiting for the fleet to fully renew is simply incompatible with current decarbonisation trajectories.

The pragmatic answer: why low-carbon fuels are needed now

Faced with this inertia, low-carbon fuels offer an immediate lever for action, without waiting for vehicle replacement. They cut the carbon footprint of the thermal fleet already on the road, the very factor ADEME identifies as dominant until 2030.

Several product families address different needs depending on vehicle type, sector and the desired level of substitution: pure products that fully replace fossil diesel, and blends that enable a gradual transition without modifying the vehicle or supply logistics.

Available transition solutions

• HVO (hydrotreated vegetable oil): a drop-in diesel substitute, compatible with most existing engines
• B100: pure biodiesel, suited to captive and dedicated fleets
• Bio-CNG: a low-carbon alternative for fleets already running on natural gas
• Blends (B30, F30, B24, XTL 10...): gradual incorporation rates, with no disruption to operations or heavy investment

These solutions do not replace electrification, they complement it. The point is not to choose between the two, but to cover the period during which the thermal fleet will keep emitting heavily, while fleet renewal gradually takes effect.

How Heeding supports this realistic, multi-fuel transition

Beyond fuel access, Heeding helps design a tailored strategy that combines gradual electrification of suitable segments with low-carbon fuels for the remaining thermal share. It is this balanced approach, rather than a choice between two competing technologies, that makes realistic decarbonisation targets achievable.

Conclusion: combine electrification and low-carbon fuels now

ADEME's study does not question the value of electrification, it clarifies the conditions for its success: controlled charging behaviour, properly sized infrastructure, and above all patience with the inertia of the existing thermal fleet. Through 2030-2035, that thermal fleet will keep weighing heavily on road transport's carbon footprint.

For a fleet manager, successful decarbonisation is therefore not a binary choice between electric and thermal, but a combination: progressively electrify the segments where it makes sense, and turn to low-carbon fuels today for the share of the fleet that will remain thermal for years to come.