History of electric Types of systems Propulsion basics Electronics basics Guemes Island ferry planned Crosscut.com
The ICE is melting Internal Combustion Engine ICE 90 year gap Steam Electric Electric 1800 1850 1900 1950 2000 2050 ELCO stops electric pleasure boats ELCO Electric Launch Company 8 charging stations on Thames E boat English Channel crossing 8 hrs, both ways Popularization of E launches Jacobi, Russia: 14 passenger E boat 3 mph Photo: Tad Pfeffer/Extreme Ice Survey Data from Wikipedia and Elco website
Electric promises lower impact to self and others: No CO warning sticker No bilge buzzer No plume of diesel smoke in the marina Clean engine compartment and topsides Charging happens at your slip and under way Great control no stalling at low speeds Simpler to use and maintain Quiet low vibration Odorless Renewable energy
Integrated outboards Simple to use Light weight portable Cost competitive with gasoline dinghies thru 2 ton boats Range is expandable Small size = easy to charge
Non integrated outboards: More customized installation More customizable range and power Charge options more limited by size For applications where weight not an issue. Larger boats Variable efficiency Requires engineering and installation Range can be upgraded later.
inboard all electric Up to 60 miles range Control, environmental and sensorial benefits compared to ICE. Charge options limited by size Competitive purchase cost Greater weight balance trim User friendly controls Can be upgraded: more batteries, generator or solar. Torqeedo.com Elco.com
Inboard gaselectric hybrid Extended cruising. Don t mind extra $ for a dual system. Power and range similar to ICE. Looses some environmental and operating cost benefits of EP Weight + depending. Torqeedo.com
How to make sense of E propulsion? Output power Input power voltage thrust Shaft power Propulsion? displacement
How to make sense of propulsion? The boat The system Speed / range Displacement Hull params Output power (drag x speed) Input power (efficiency) Voltage Current Capacity RPM (s) Pitch Diameter Cost Loop until satisfied
Thrust at speed Speed / range Displacement Hull params Output power (drag x speed) Input power (efficiency) Voltage Current Capacity Cost Catalina 30, Data thanks to James Lambden, www.electricboatdesign.com POWER required = Drag (thrust) x speed Dra ag (thrust req quirement), lbf knots
Definitions and system types Speed / range Displacement Hull params Output power (thrust x speed) Input power (efficiency) Voltage Current Capacity Cost E overall = Eprop x Ebattery x Emotor x Egear x Ewiring x Echarging Component efficiencies 98% 99% 98% 90% 85% 75% 60% Typical gasoline or diesel conversion 33% Overall propeller battery motor gear reduction controller wiring charger
Sizing Speed / range Output power Input power Voltage Displacement Current Cost Hull params (drag x speed) (efficiency) Capacity vs efficiency watts input tons 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 EP Carry 0.25 Torqeedo 0.5 66 Oceanvolt 3.5 8.5 Electric Yacht 5 30 Elco 4 40 Efficiency Power (W)
Propeller and motor matching All motors have their efficient RPM operation range. Larger diameters, higher pitch and slower rotation lower blade area. Propeller Diameter Effect on Thrust, 40 watts input 6.0 5.0 st 4.0 ru 30 3.0 th lb 2.0 1.0 0.0 5 7 9 11 13 15 17 propeller diameter, inches Gearing matches motor to propeller.
100 Ah lead acid battery Batteries 50 Ah battery 110 100 % battery capacity 90 80 70 60 50 40 30 0 10 20 30 40 50 60 Amp draw A lead acid 100 AH battery will lose 50% of its capacity at 40 amps draw. (when new). A 48Ah LiFePO4 will lose about 5 8 % at 40 amp draw. Choice of battery affects range, speed etc. A Lead acid system can be upgraded to one of these in the future.
Volts, Amps, Watts, Horsepower Volts, V Amps, A Power = V x A, Watts, W Amp capacity = A x time, Amp hours, Ah Energy = V x A x time, Watt hours, Wh 1kW motor system Volts: 3 battery system = 12v x 3 = 36 Volts Amps: 0 to 28 Amps depending on throttle Power: 0 to 36 x 28 = 1000 Watts depending on throttle Amps Motor system volts + + + battery battery battery Amp capacity: Each battery (idealized) can provide 4 amps for 20 hours = 80 Ah Energy: Ah x Volts = 80 Ah x 36V = 2880Wh
Review shore power generator/ solar / wind throttle charger controller gear reduction electric motor battery bank
Questions Comments Feedback