WHITEPAPER: Comparative analysis of energy consumption and productivity in electrified vs. Diesel compact excavators

1. Executive summary

The off‑highway machinery ecosystem—construction, agriculture, mining, and material handling—is approaching a critical pivot. Global component sales like hydraulics, gears, electronics, and electric powertrains are projected to reach ~$50 billion by 2030 (1), yet technology adoption remains slower than in on‑road markets. Three structural factors explain the lag:

• Sparse, fragmented policy drivers. Unlike automotive, few targeted regulations incentivize low‑emission, high‑safety, or automated off‑highway machines across geographies. Adoption of higher‑value systems, like advanced electronics, therefore, concentrates in narrow niches, limiting scale effects.

• OEM conservatism combined with value‑sensitive end users. OEMs typically invest when customers prove willingness to pay. In construction, cost sensitivity is high; lower‑value models often grow volumes faster than high‑value configurations, and OEM pricing pressure constrains suppliers’ ability to scale new technologies. Competitive pressure from Chinese OEMs, however, is pushing incumbents to differentiate with electrification and advanced features.
• High‑mix, low‑volume fragmentation: Off‑highway spans dozens of machine families and duty cycles; some variants sell only a handful of units annually. The result is complex integration, limited reuse, and slower learning curves for new tech. Emerging “electrify‑the‑jobsite” concepts—modular power, energy hubs, and platform approaches—aim to reduce these barriers. 

Despite these headwinds, two pathways can unlock outsized value. The first is the electrification of compact and mid‑range equipment, where duty cycles include frequent pauses and partial loads. Here, PMAC motors deliver high torque density and instant response; electric drivelines consume near‑zero energy at idle, and OEM tools report practical runtimes (e.g., ~4 h at light duty from a 20-kWh pack) with ~50‑minute fast‑charge to 80%—compatible with normal shift routines. The second is a software‑driven and modular deployment, borrowing from automotive SDV concepts and “whole‑site” electrification. By shifting customization into software and standardizing charging/power interfaces, suppliers and OEMs can scale features across platforms while controlling cost and complexity. This whitepaper contributes practical evidence by comparing energy consumption and productivity for a representative compact electric excavator versus a diesel counterpart under light and medium urban/utility duty cycles. The findings:

• Electric delivers lower operational energy (~5.0–6.7 kWh/h vs diesel ~2.2–3.4 L/h ≈ 22–34 kWh/h input), driven by drivetrain efficiency and zero‑idle behavior.
  

• Productivity is equivalent, and it’s supported by instant torque, steadier hydraulics, and significantly lower NVH (Noise, Vibration and Harshness).
  

• Shift planning is simple with a single fast‑charge window.

• Diesel remains the right tool for remote, continuous high‑load tasks until site power becomes commonplace. 
  

The remainder of the report quantifies these results (Ch. 2), examines operator and cycle‑execution effects (Ch. 3), and translates them into day‑plan guidance and deployment checklists (Ch. 4). These findings complement the framework established in our earlier analysis, “Understanding the Total Cost of Ownership for Electric Vehicles”, by linking performance‑based outcomes directly to planning and cost‑evaluation practices.

2. Energy consumption

Understanding energy consumption across light‑ and medium‑duty duty cycles is foundational to compare electrified and diesel compact excavators. While both machine types deliver broadly comparable digging performance, their energy profiles differ dramatically, not only in raw consumption but also in how energy is used during different work phases. This chapter quantifies those differences using representative data from a 2.6–2.8 t class electric compact excavator and its diesel counterpart.

The reference electric excavator operates with a 20-kWh lithium‑ion battery at 48 V, driving a permanent‑magnet traction motor rated at 18 kW peak and 14.8 kW continuous. Under typical use, the machine provides an indicative runtime of up to 4 hours (2), depending on workload and hydraulic demand. But runtime varies significantly by duty cycle. The official runtime/charging calculator shows that under moderate workloads, the machine achieves several hours of continuous operation—while in mixed cycles, pauses and idling extend usable runtime further because electric systems consume near‑zero energy when not actively working (3). This behavior sharply contrasts with diesel machinery, where idling continues to burn fuel regardless of workload. In many jobsite studies, compact diesel excavators idle for 20–40% of the shift (3); this directly increases fuel consumption without contributing to productive work.

To derive a practical kWh per operating hour, we divide usable energy (20 kWh) by typical runtimes observed in light/medium scenarios:

• Light duty (fine trenching, frequent pauses):

  Runtime ~4.0 h → ~5.0 kWh/h

• Medium duty (continuous trenching in standard soil):

  Runtime ~3.0–3.5 h → 6–6.7 kWh/h

This range aligns with the machine’s continuous power draw and reflects the efficiency of permanent magnet motors, which maintain high conversion efficiency across varying loads.

Now let’s look at the energy profile of a comparable diesel machine. Because compact excavators in this class rarely publish OEM fuel consumption figures, industry validated ranges must be used. Multiple independent datasets confirm that mini excavators in the 1–10-ton category typically consume 1–4 L/h, depending on load and digging intensity. We can then make an estimate of consumption for a machine with ~23 hp (comparable to our reference diesel excavator):

• Low load: ~2.2 L/h

• Medium load: ~3.4 L/h

• High load: ~4.5 L/h

For the purposes of this whitepaper—focused on light/medium duty—the relevant ranges are 2.2–3.4 L/h. Idling remains a large contributor to total fuel use. Diesel engines consume fuel continuously at idle, often 0.8–1.2 L/h, meaning even modest idle percentages inflate total fuel burn significantly. This effect is absent in electric operation. To evaluate energy consumption on a common basis, we compare the raw hourly consumption:

Electric (Light/Medium)

• Light duty: ~5.0 kWh/h

• Medium duty: ~6–6.7 kWh/h

(Real world value depends on operator behavior, hydraulic load, and idling share.)

Diesel (Light/Medium)

• Light duty / low load: ~2.2 L/h

   

• Medium duty: ~3.4 L/h

The more meaningful comparison for operators is operational energy (4), that reflects how much energy is consumed to deliver equivalent digging performance under similar workloads. In operational terms:

• Electric machines consume less total energy per productive hour because their drivetrain efficiency is significantly higher and idling draws no power.

   

• Diesel machines consume more energy during non-productive time (idling, short pauses, boom repositioning), which accumulates disproportionately in light and medium duties.

Runtime tools show that even on a full battery, electric machines deliver 4–5 hours of usable operation in realistic conditions with no worries about fuel burned at idle.  A diesel machine applying the same workload pattern—where 20–40% of the time may be spent idling—would see total consumption rise above the theoretical 2.2–3.4 L/h values and often into 3–4 L/h effective averages.

In light/medium scenarios, electric averages ~5.0–6.7 kWh/h; diesel consumes ~2.2–3.4 L/h—equivalent to ~22–34 kWh/h input energy. This comparison highlights several key conclusions:

• Electric excavators are inherently more energy efficient, using only the energy required for actual hydraulic or traction work.
• Diesel excavators suffer from idle penalties that inflate consumption, particularly in light and medium duty cycles where task interruptions are frequent.
• In real jobsite conditions, the electric machine’s effective energy consumption per productive hour is lower, even when absolute energy per hour seems similar.

• These differences scale directly with runtime: a 20-kWh pack delivering 3–4 hours of real work indicates high efficiency relative to the diesel machine’s chemical energy input.

3. Productivity and operator factors

Productivity in compact excavator applications is governed by how effectively the machine converts energy into hydraulic work, how consistently that work can be performed, and how the operator experiences and controls the machine over a full shift. In light‑ and medium‑duty construction tasks, the differences between electric and diesel platforms become increasingly visible.

This section evaluates key productivity determinants: hydraulic performance, torque delivery, cycle execution, and operator experience, comparing an electric compact excavator with its diesel equivalent in the same 2.6–2.8 t class.

3.1 Powertrain characteristics

Electric compact excavators use permanent magnet motors that deliver maximum torque instantly from zero RPM. This gives them immediate response to operator commands, without waiting for the engine to reach its torque band—a core performance difference from diesel machines. Electric drivetrains also maintain high efficiency across varying loads, enabling smoother implement transitions and quicker reactions during trenching, leveling, and repositioning.

Diesel engines, by contrast, rely on combustion-driven torque curves and must increase RPM to reach peak torque. This creates transient lag that can extend cycle times, especially during fine repositioning or rapid switching between boom, arm, and slew movements. As widely noted in comparative equipment evaluations, these characteristics often make diesel machines feel less precise in light and medium-duty tasks.

As a result, in applications where responsiveness and control matter more than raw horsepower, electric excavators typically deliver more consistent cycle execution with less operator compensation.

3.2 Hydraulic performance

Hydraulic performance is a core productivity determinant for any excavator. The reference electric compact excavator features a main pump flow of approximately 58 L/min, along with breakout and tear‑out forces (≈22.3 kN breakout; ≈17–18 kN arm forces depending on configuration) that match or closely mirror the diesel equivalent. Industry comparisons confirm that electric compact excavators in this class maintain comparable hydraulic pressure and implement performance to their diesel counterparts. In some cases, the electric variant slightly exceeds the diesel version in continuous motor power or hydraulic consistency because electric motors maintain stable output regardless of RPM fluctuations.

For light‑ and medium‑duty tasks—including utility trenching, backfilling, grading, and site preparation—the result is functional parity in digging performance. Operators do not need to adjust their technique or expectations when switching between electric and diesel machines for these workloads.

3.3 Cycle consistency

Cycle consistency is another essential productivity metric, particularly in compact equipment that frequently performs short, repetitive cycles. 
Electric machines benefit from:

• Immediate control response due to electric motor torque characteristics.

• Reduced slew and implement vibration because the driveline lacks combustion related pulsations.

Lower vibration and noise contribute to improved operator precision, especially when working in confined or urban environments. The reference electric excavator produces significantly lower exterior and interior sound levels (LpA ~74 dB, LWA ~84 dB) (2) compared to typical diesel machines, which reduces cognitive load and fatigue over a workday. 

The diesel comparator, while fully capable within this weight class, introduces more variability in cycle timing due to engine speed adjustments every time hydraulic demand changes, higher noise and vibration and hydraulics readiness. These effects are subtle but meaningful, particularly in repetitive medium duty cycles such as trenching in standard soil or material placement around utilities.

Author: Francesco Patroncini