Marine Electrification Feasibility: Environmental & Economic

5.2 Marine Electrification System

Feasibility Study for the 'Marcel Carné' Vessel

System Architecture

Fully electric propulsion typically consists of an energy storage system (ESS/Battery) supplying DC power to an inverter, which converts it to AC for the electric motor driving the propeller. This eliminates local emissions and reduces noise.

Operational Energy Demand

Worst-case scenario: June 16th (high traffic).

Route: Seine River loop + Extended Canal Saint-Martin route.

Total Energy Required (E_day): 209 kWh.

Battery Capacity Sizing

To guarantee 209 kWh at the propeller with 95% system efficiency, 220 kWh must be drawn from the battery. Furthermore, to maximize battery life ( LiFePO4), we restrict operation to a 30%–90% SOC window (60% usable depth).

Configuration & Redundancy

The 380 kWh capacity is split equally between two independent propulsion lines (Port & Starboard). This preserves 'twin-screw redundancy': if one line fails, the other remains independently powered.

Recharging Strategy: Assessment

Option A: Opportunity Charging (Rejected)

Charging between loops (15 mins) requires ~260 kW power. High thermal stress, accelerated battery aging, and costly quayside infrastructure (300 kW grid connection).

Option B: Overnight Charging (Selected)

Charging once daily during non-operational hours (night). Lower power requirement (30-60 kW), safer thermal management, and standard infrastructure costs.

Battery System Characteristics

Technology: LiFePO4 (Lithium Iron Phosphate)

Estimated Mass: 1.9 – 3.5 tonnes

Estimated Volume: 1.16 – 2.7 m³

Cycle Life: 2,000 – 7,000 cycles (~12.5 years)

Emissions Performance (CO2)

Including production and grid mix, the electric solution offers a ~89% reduction in daily operational carbon footprint (10.5 vs 96.5 kg CO2-eq).

Financial Analysis: CAPEX

<ul><li><strong>Vessel Investment (~200 k€):</strong> estimated at 525 €/kWh.<ul><li>Battery System: ~350 €/kWh (~133 k€).</li><li>Propulsion Components: +50% factor (~67 k€).</li></ul></li><br><li><strong>Infrastructure Investment (~50 k€):</strong><ul><li>Single low-power DC charging point.</li><li>Includes hardware and quay-side integration.</li></ul></li><br><li><strong>Total CAPEX: ~250 k€</strong></li></ul>

Financial Analysis: OPEX

Electricity Cost: 0.16 – 0.19 €/kWh (French business rate).

Daily Recharge: ~220 kWh / day.

Annual Energy Cost: ~13,300 € / year.

Conclusion & Recommendation

Excellent environmental performance (lowest emissions).

High CAPEX (250 k€), significant battery weight/volume, and non-negligible OPEX.

NOT SELECTED. Due to economic and integration constraints, full electric propulsion is not the preferred solution for the Marcel Carné at this time, though it remains a relevant long-term option.