Seastead Design Analysis Report

Generated based on provided specifications. All estimates are preliminary engineering approximations suitable for concept feasibility, not for construction. Assumes Marine Grade Aluminum (5083/5086/6061-T6). "Unsafe" conditions flagged where applicable.

1. Solar Power & Energy Balance

1.1 Solar Array Specifications

ParameterValueNotes
Roof Area (Equilateral Triangle, 44ft side)836 ft² (77.7 m²)Area = (√3/4) * a²
Usable Area (walkways, hatches, structure)~650 ft² (60.4 m²)~78% coverage factor
Panel Efficiency (Marine Grade, 2024+)22.5%High efficiency monocrystalline
Installed Peak Power (DC)13.6 kWp60.4 m² * 1000 W/m² * 0.225
Derating (Temp, Salt, Angle, Wiring, Age)0.72Conservative marine derating
Effective Peak Power9.8 kW

1.2 Caribbean Daily Production (Average)

MetricValue
Average Peak Sun Hours (Caribbean, Horizontal)5.5 hrs/day
Average Daily Production (AC)53.9 kWh/day
Annual Average (Accounting for storms/cloudy weeks)~48 kWh/day

1.3 Battery Bank (500 kWh LFP)

ParameterValue
Usable Capacity (80% DoD for longevity)400 kWh
Specific Energy (Pack Level, Marine)110 Wh/kg (0.05 lbs/Wh)
Total Battery Weight25,000 lbs (11,340 kg)
Cost @ $90/kWh (Cell/Pack Level 2024/25 est.)$45,000
Installed Cost (BMS, Fire Suppression, Racks, Wiring) ~1.8x$81,000
Critical Weight Alert: Batteries alone (25,000 lbs) exceed the stated "rated buoyancy at desired waterline" of 27,500 lbs. Structure, hull, systems, payload must fit in remaining 2,500 lbs. This design is UNSAFE/impossible at 500 kWh with 27,500 lbs displacement. See Section 4 (Weight Budget) and Summary.

1.4 Average Hotel Load (Non-Propulsion)

ComponentAvg Power (W)Daily kWhDuty Cycle / Notes
AC (1 unit running, 2 idle)1,20028.812k BTU Inverter, COP 3.5, 35% duty
Refrigeration (Fridge/Freezer)1503.6High efficiency marine
Water Makers (2x, 1 running avg)80019.260 GPH Spectra type, 8 hrs/day
Electronics/Nav/Starlink (2x)2506.0Continuous
Lighting / USB / 120V Misc3007.2
Ventilation / Pumps / Controls2004.8
Total Hotel Load2,900 W69.6 kWh
Energy Deficit: Average Hotel Load (69.6 kWh) > Average Solar Production (53.9 kWh). Deficit = 15.7 kWh/day. Batteries will drain without propulsion. Propulsion power = 0 W average unless generator/kite used.

1.5 Wind Station Keeping (Head to Wind)

Drag Coeff (Cd) Estimates: Superstructure (Triangle wall 44x7 + Roof) ~1.2. Legs (3x NACA 0035, 10.75 submerged, 10.75 exposed) ~0.04 (streamlined) + Struts/Wires. Frontal Area ~ 308 ft² (House) + 70 ft² (Legs/Struts) = 378 ft² (35 m²).

Wind SpeedDrag Force (lbf)Thrust Required (lbf)Propulsive Power (kW) @ 50% Eff
30 MPH (13.4 m/s)~1,1001,100~7.5 kW
40 MPH (17.9 m/s)~1,9501,950~17.5 kW
50 MPH (22.4 m/s)~3,0503,050~34 kW

6 x RIM Drives (1.5ft dia). Typical max continuous power ~5-10 kW each. Total max ~30-60 kW. Can hold station up to ~45-50 mph if batteries allow. At 50 mph, 34 kW drains 500 kWh in 14.7 hours (ignoring hotel load).

1.6 Sailing / Keel Mode (Beam Reach)

Lateral Plane Area (3 Legs submerged): 3 * (10.75ft * 2.975ft avg chord) = ~96 ft² (8.9 m²). Aspect Ratio ~ 3.6 (per leg).

1.7 24/7 Cruising Speed on Solar Surplus

Since Hotel Load > Solar Production, Surplus = 0 kW. Cannot cruise 24/7 on solar alone.

If Hotel Load reduced to 1.5 kW (no AC, minimal water): Surplus ~2.5 kW avg. 6 RIM Drives ~ 50% eff at low speed. Thrust Power ~1.25 kW. Resistance @ 3 kts ~ 1.5 kW. Max Solar-Only Speed ~ 2.5 - 3 knots.

2. Battery Range Table (No Solar Input)

Assumptions: 500 kWh Total, 400 kWh Usable (80% DoD). Hotel Load 2.9 kW constant. Propulsion Efficiency 50% (Battery to Thrust). Resistance Curve estimated for 27,500 lbs Displ, 3x Foil Struts, 44ft Triangle House. Stabilizers ON reduces roll/pitch drag slightly but consume ~500W.

2.1 Stabilizers OFF

Speed (kts)Speed (MPH)Total Drag (lbf)Prop Power (kW)Total Power (kW)Hours (400 kWh)Range (nm)Range (Statute Mi)
44.6~450~5.58.447.6190219
55.8~750~11.514.427.8139160
66.9~1,200~22.024.9