History of electric Types of systems Propulsion basics Electronics basics - Guemes Island ferry planned Crosscut.com - EP Carry
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• History of electric
• Types of systems
• Propulsion basics
• Electronics basics
Guemes Island ferry planned‐ Crosscut.com
The ICE is melting…
Internal Combustion Engine
ICE
Steam Electric
Electric “90‐year gap”
1800 1850 1900 1950 2000 2050
ELCO stops
p electric pleasure
p boats
ELCO Electric Launch Company
8 charging stations on Thames
E‐boat English Channel crossing 8 hrs, both ways
Popularization of EE‐ 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 energyIntegrated
outboards
• Simple to use
• Light weight‐ portable
• Cost competitive
p with ggasoline
• dinghies thru 2 ton boats
• Range is expandable
• Small
S ll size
i = easy to
t charge
hNon‐integrated
outboards:
• More customized installation
• More customizable range and
power
• Charge options more limited
by size
• For applications where weight
not an issue.
• Larger
g boats
• Variable efficiency
• Requires engineering and
installation
• Range can be upgraded later.inboard all‐electric
• Up to 60 miles range
Torqeedo.com
• 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,
solar
generator or solar.
Elco.comInboard gas
gas‐
electric hybrid
• Extended cruising.
• Don’t mind extra $ for a dual
system.
Torqeedo.com
• Power and range similar to ICE.
• Looses some environmental
and operating cost benefits of
EP
• Weight +‐ depending.How to make sense of E propulsion?
Output power Input power
voltage
thrust
displacement
Sh ft power
Shaft Propulsion?How to make sense of propulsion?
The boat The system
Speed / range Output power Input power Voltage
Current Cost
Displacement (drag x speed) (efficiency) Capacity
Hull params RPM (s)
Pitch
Diameter
Loop until satisfiedThrust at speed…
Speed / range Output power Input power Voltage
Displacement Current Cost
Hull params (drag x speed) (efficiency) Capacity
• Catalina 30,
quirement), llbf
Data thanks to
James Lambden, www.electricboatdesign.com
Draag (thrust req
POWER required
=
Drag (thrust) x speed
knotsDefinitions and system types
Speed / range Output power Input power Voltage
Displacement Current Cost
Hull params (thrust x speed) (efficiency) Capacity
E overall = Eprop x Ebattery x Emotor x Egear x Ewiring x Echarging
Component efficiencies
98% 99% 98%
90%
85%
75%
60%
Typical 33%
ggasoline or
diesel
conversion
Overall propeller battery motor gear reduction controller wiring chargerSizingg Speed / range
Di l
Displacement
Output power Input power Voltage
C
Current C
Cost
vs Hull params (drag x speed) (efficiency) Capacity
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
Propeller Diameter Effect on Thrust,
400 watts
atts input
put
6.0
5.0
ts 4.0
ur
ht 3.0
30
lb 2.0
• All motors have their efficient RPM 1.0
operation range. 0.0
5 7 9 11 13 15 17
• Larger diameters , higher pitch and propeller diameter, inches
slower rotation lower blade area.
• Gearing matches motor to propeller.Batteries
100 Ah lead acid battery 50 Ah battery
110
100
90
% battery capacity
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
draw. (when new)
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
Motor
•Volts, V
Amps, A
•Amps, system
t
•Power = V x A, Watts, W
•Amp capacity = A x time, Amp hours, Ah Amps
•Energy = V x A x time , Watt hours, Wh volts
+ ‐ + ‐ + ‐
1kW motor system battery battery battery
•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
•Amp capacity: Each battery (idealized) can provide 4 amps for 20 hours = 80 Ah
•Energy: Ah x Volts = 80 Ah x 36V = 2880WhReview
generator/
shore
solar /
power
wind…
throttle charger
controller
gear battery bank
electric motor
reduction• Questions • Comments • Feedback
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