Electric outboard motor

Electric outboard motors are an option for boat propulsion. Most electric outboard motors have 0.5 to 4 kW direct current (DC) electric motors, operated at 12 to 60 volts DC. These systems have the propeller fixed directly to the motor, which is mounted in the lower unit under water – see trolling motor. This setup limits the power output. Recently developed outboard motors are powered with an alternating current (AC) or DC electric motor in the power head like a conventional petrol engine. With this setup, a motor can produce 10 kW output or more and is able to replace a petrol engine of 15 HP or more. The advantage of the induction or asynchronous motor is the power transfer to the rotor by means of electromagnetic induction. As these engines do not use permanent magnets, they require less maintenance and develop more torque at lower RPM.

Power supply

The advantages of electric boat propulsion systems are the low maintenance costs, the limited noise and emission-free operation. The disadvantage is the limited range due to the weight and size of the batteries. There are several battery types in use today with various power-to-weight ratios:

Charging the batteries with a photovoltaic solar system, wind turbines and towed generators (when traveling under sails or anchored in strong current) can make the system independent of any external energy source. For longer trips, the system can have a range-extending gasoline or diesel generator which recharges the batteries.

Costs

Electric outboard motors cost two to three times the cost of a four-stroke petrol engine, but operation costs are lower. A 1-kilowatt electric outboard motor, including a lithium battery, can be purchased from US$1800.00 (2016) which is already competitive to a 3 HP petrol engine. Electric motors are usually much more efficient in power-to-weight ratios. Generally 17.0 pounds of thrust equals 1 HP. However, one requires at least twice as much power to compensate for added weight.[1]

Models

In the following section a overview and comparison of electric outboard motors.

To compare with petrol engines: 1 HP = 0.745 kW and 1 kW = 1.341 HP.

Torqeedo[2]

Ultralight Travel Cruise Deep Blue
403 503 1003 1003 C 2.0 4.0 10.0 40 80
Input power (W) 400 500 1000 2000 4000 10000 33000 66000
Propulsive power (W) 180 220 480 1120 2240 5600 16200 32400
Static thrust (N) 147 178 302 511 841 1401
Max. overall efficiency (%) 45 44 48 56 54
Battery type Build-in External
Battery voltage (V) 29.6 24 48 345
Battery capacity (Wh) 320 915 320 530 915 2685 2x 2685 12800 30500
Motor weight (kg) 4.4 8.9 17.5 18.3 59.8 139
Battery weight (kg) 4.5 6.0 5.0 5.5 6.0 24 2x 24 149 256
Max. prop. speed (rpm) 1200 700 1200 1300 1400 2400

ePropulsion[3]

Lagoon Spirit Navy
1.0 3.0 6.0
Input power (W) 300 1000 3000 6000
Propulsive power (W) 500 1650 3300
Static thrust (N) 111 294 1246
Max. overall efficiency (%) 50 55
Battery type Build-in External
Battery voltage (V) 22.2 40.7 48
Battery capacity (Wh) 333 1017 3042 2x 3042
Motor weight (kg) 1.5 9.8 26.8 28.8
Battery weight (kg) 2.5 8.8 31.5 2x 31.5
Max. prop. speed (rpm) 1800 1200 1800 1550

AquaWatt[4]

Green
Power Racing Thruster Flash
Input power (W) 15500 26000 50000
Propulsive power (W)
Static thrust (N)
Max. overall efficiency (%)
Battery type External
Battery voltage (V) 48 80 144
Battery capacity (Wh)
Motor weight (kg) 52 63 94 98
Battery weight (kg)
Max. prop. speed (rpm)

Elco[5]

Electric Propulsion
EP-9.9 EP-14 EP-20
Input power (W) 4800 6240 7920
Propulsive power (W)
Static thrust (N) 578 907 1068
Max. overall efficiency (%)
Battery type External
Battery voltage (V) 48
Battery capacity (Wh)
Motor weight (kg) 29.5 38.6 40.8
Battery weight (kg)
Max. prop. speed (rpm)

Pure Watercraft[6]

Pure Outboard
Input power (W) 20000
Propulsive power (W)
Static thrust (N)
Max. overall efficiency (%)
Battery type Build-in
Battery voltage (V) 350
Battery capacity (Wh) 6000
Motor weight (kg) 41.7
Battery weight (kg) 42.2
Max. prop. speed (rpm)

KARVIN [7]

KARVIN 2700 KARVIN 5500
Amp hour rating. min. 80 Ah battery 120 Ah battery
Battery voltage - 3 in 1 24V/36V/48V 24V/36V/48V
RPM max. 900/1200/1500 900/1200/1500
Comparable petrol outboards in HP (thrust) 9,5 19,5
Min. overall efficiency (%) 85% 85%
Motor type brushless without gear-box => DirectDrive
Power max. kW/HP 2,7 / 3,6 5,5 / 7,4
Torque 27, 5 Nm 43,2 Nm
Static thrust in lbs 210 290
Tensile force [kg] 95 133
Body material aluminium
Propeller material stainless steel
Shaft length Long L (510 mm) / Short S (380 mm)
Continuous regulation Yes
Forward and Reverse Yes
Engine weight 22 kg 26 kg
Electronics Electronic control + Electronic Safety Key + Electronic manual throttle + Immobiliser

See also


References

  1. "Calculator for electric boat motors". Retrieved 2010-11-11.
  2. "Torqeedo 2017 catalog" (PDF).
  3. "ePropulsion 2016 brochure" (PDF).
  4. "AquaWatt 2016 catalogue" (PDF).
  5. "Electric Outboards | Electric Outboard Motors". www.elcomotoryachts.com. Retrieved 2017-01-31.
  6. "Pure Outboard". Pure Watercraft. Retrieved 2017-01-31.
  7. "KARVIN electric outboard motor". KARVIN MOTORS.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.