Battery-Electric Retrofit of Motorized Fishing Boats on the Odisha Coast: A Duty-Cycle-Driven Techno-Economic Assessment with Shared Solar Shore Charging

Odisha's marine fishery operates about twelve thousand motorized country boats, most of them fibreglass beach-landing craft driven by small two-stroke petrol outboards or wooden gill netters with single-cylinder diesel inboards. Fuel is the largest controllable operating cost, yet no peer-reviewed study located by the authors has assessed battery-electric propulsion for these craft, and no measured duty cycles exist. This paper builds the assessment from physical first principles and states every assumption. Calm-water resistance is computed with the ITTC-1957 friction line plus a residuary term calibrated to the installed power and service speed of each archetype. A phase-structured stochastic duty-cycle generator produces 3,600 trips per case, which drive battery sizing through a mass-spiral fixed point, an hourly simulation of a solar charging hub shared by twenty boats, and a 10,000-draw Monte Carlo techno-economic model. The dominant engineering lever is speed: reducing cruise speed by one knot lowers transit energy by 54 percent because these hulls operate near hull speed, which halves the required battery to about 21 kWh. With locally integrated drives and packs, the outboard craft outside turtle-protection zones returns a median net present value of INR 8.81 lakh per boat and a 3.4-year discounted payback. The result does not survive imported branded hardware, low utilization inside the seven-month turtle-ban zones, or the low fuel burn of diesel inboards, each of which yields a median value near or below zero. A closed-form break-even utilization of 66 trips per year is derived and verified. The findings are simulation-only, and a stratified field logging protocol is specified to replace the synthetic duty cycles before any investment decision.