Catenary electric truck systems—such as Siemens’ eHighway concept—electrify highway lanes with overhead lines that trucks connect to via pantographs, drawing power directly from the grid while driving and using on-board batteries or engines off-wire. The idea is simple and familiar from rail, but its deployment on open-access roads raises questions about cost, interoperability, and long-term flexibility. At Energy Solutions, we analyse how catenary trucks compare with battery-electric and hydrogen options in terms of energy efficiency, infrastructure cost, and corridor-level ROI.
Catenary systems for trucks involve overhead contact lines installed above selected highway lanes. Hybrid or full-electric trucks are equipped with a roof-mounted pantograph that automatically connects to the lines, drawing power for traction and (in some designs) for charging on-board batteries. When leaving the electrified lane, the truck reverts to battery or combustion power.
Energy Solutions benchmarks are based on published Siemens eHighway data, independent ERS studies, and internal freight corridor models. Costs are expressed as order-of-magnitude ranges; actual project economics are highly context-specific.
The main advantage of catenary trucks is high electrical efficiency due to fewer conversion steps compared with hydrogen and smaller on-board batteries than full BEVs. But this comes at the cost of fixed infrastructure.
| Option | Tank-to-Wheel Efficiency (%) | Vehicle Capex (Diesel = 1) | Infrastructure Capex (Corridor-specific) |
|---|---|---|---|
| Diesel ICE | ~40–45 | 1.0 | Low (existing roads & stations) |
| Battery-electric truck (BEV) | ~70–80 | 2.0–2.5 | Fast-charging hubs and grid upgrades. |
| Hydrogen fuel cell truck | ~45–55 | 2.2–2.5 | Hydrogen production and stations. |
| Catenary electric truck (ERS corridor) | ~75–85 (on-wire) | 2.0–2.3 (pantograph + battery) | High: overhead lines & substations per corridor. |
Source: Energy Solutions modelling; catenary values refer to time spent under wires.
Overhead electrification is not suitable for every road. It is most compelling on busy freight corridors with a high density of heavy trucks and predictable flows. Key criteria include:
| Corridor Type | Heavy Truck Volume | ERS Viability | Comments |
|---|---|---|---|
| Major interstate/highway freight spine | High | High | Best candidate for early deployments. |
| Regional connector with mixed traffic | Medium | Medium | Viability depends on regional freight concentration. |
| Low-volume rural highways | Low | Low | Better suited to BEVs or hydrogen without ERS. |
The economics of ERS are best evaluated at the corridor level. The capital cost per kilometre must be amortised over the energy delivered to trucks and the emissions avoided compared with diesel.
| Parameter | Value (Order-of-Magnitude) | Notes |
|---|---|---|
| Capex per kilometre | 2–5 million EUR/km | Overhead lines, masts, substations, and civil works. |
| Annual energy delivered (per km) | 10–40 GWh/year | Depends on truck volumes and utilisation. |
| Levelised ERS cost per kWh | 0.05–0.15 EUR/kWh | Highly dependent on utilisation and financing terms. |
Source: Energy Solutions ERS cost models; illustrative cost per kWh vs truck-km per year.
Critics of ERS argue that building fixed overhead infrastructure along highways may lock regions into a specific technology just as battery and hydrogen solutions are rapidly evolving. If truck fleets shift toward different powertrains or routes, ERS assets risk underutilisation.
Governance is also complex: highways cross jurisdictions, and aligning funding, tariffs, and access rules among public and private actors is non-trivial. Some analysts argue that comparable decarbonisation gains might be achieved by investing in rail freight, charging hubs, and hydrogen networks instead. ERS proponents respond that overhead lines leverage existing engineering experience and offer a highly efficient option where freight density is high.
By 2030, most ERS deployments are expected to be pilot or early commercial corridors. By 2035, in ambitious scenarios, several major freight routes in Europe or other regions could host significant ERS networks, serving a share of long-haul truck traffic while BEVs and hydrogen trucks cover other routes.
| Scenario | Diesel & Other Fossil (%) | Battery-Electric (%) | Hydrogen FCEV (%) | Catenary ERS Trucks (%) |
|---|---|---|---|---|
| Conservative ERS | 60–70 | 15–25 | 10–15 | 3–7 |
| Balanced | 45–60 | 20–30 | 10–20 | 5–15 |
| ERS-forward | 40–50 | 15–25 | 10–15 | 15–25 |
Source: Energy Solutions long-haul freight scenarios; shares expressed in energy terms.
Catenary trucks use similar overhead line technology but are designed for open-access highways rather than dedicated bus or tram lanes. They can connect and disconnect while moving and typically rely on on-board batteries or engines when off-wire.
In principle, yes—if pantographs and electrical interfaces are standardised. Ensuring interoperability across OEMs is crucial for utilisation. Without common standards, ERS risks fragmentation and limited fleet adoption.
ERS and rail are not mutually exclusive. Rail remains highly efficient for bulk freight, while ERS can target segments where rail is impractical or capacity constrained. Policymakers should evaluate corridor-by-corridor trade-offs based on existing rail networks, land use constraints, and long-term freight patterns.