Β. What types of boats are suitable for electrification?
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Yachts, displacement boats, multi hulls, kayaks, dinghies and tenders are all perfectly suited for electric motors.
The first revival of electric boating took place in 1970’s due to the global energy crisis. As a result there was a resurrection of recreational electric boats.
Today’s drive for electric boating has come from an added focus on sustainability helped by the broader success and interest around electric cars with Tesla leading the way.
Europe and USA are leading the march in electric boating spurred on by government legislation that has banned powered boats along a large number of internal waterways.
As a result of this global demand for cleaner and more sustainable energy the technology behind electric boating has significantly advanced. The demand also means that going electric is now not only an option for corporate companies or wealthy indivduals. With electric motors now starting from as little as €2,000 its an attractive option for the many, not just the few.
Yachts, displacement boats, multi hulls, kayaks, dinghies and tenders are all perfectly suited for electric motors.
Any speed boat plus displacement boats that need more than 8 hours of motoring.
There are many!
First step is to think how you wish to use your boat, what the conditions of local waterway and what is the range and speed you are looking for. Generally speaking ;
1 kilo Watt (kW) = 1.35 Horse Power (HP)
However, in real life on a displacement style craft:
1kW replaces 3HP!
Why?
If current diesel performance is adequate: replace with 1/3 in kW
If diesel power is unknown use the follow empiric rule:
*Motor size rule: kW rating of motor needed = displacement x 2
Size of motor depends on:
Most recreational electric boats operate at 24 / 36 / 48V
Minimum battery requirements:
2-3 hours boating (auxiliary drive on yachts): motor kW x 1.5 = battery capacity in kWh
6-7 hours boating (motor boats): motor kW x 2.5 = battery capacity in kWh
EXAMPLES:
19’ couta boat with 3.6kW inboard (sailing boat)
3.6 x 1.5 = 5.4kW battery bank (36V / 150Ah) à total weight approx 135kg
20’ classic launch with 4.2kW Pod motor (motor boat)
4.2 x 2.5 = 10.5kW battery bank (48V / 225Ah) à total weight approx 260kg
High quality lead acids such as sealed AGM deep cycle batteries are most cost effective for most displacement boat applications.
Approx 500 cycles over 10 year period.
PRO’s:
CON’s:
In some instances Lithium batteries are desirable for their benefits over lead acid
Approx 2000 cycles over 10 year period.
PRO’s:
CON’s:
Lead-Acid and Lithium both have a life expectancy of approx 10 years max
In these 10 years a Lead Acid battery will give up to 500 discharge cycles
on the other hand in these 10 years a Lithium battery will give up to 3000 discharge cycles
Lithium is 3 times more expensive than Lead Acid
If you use the boat a lot (more than 150 times per year) Lithium works out cheaper
As this is often not the case with recreational boats, the remaining benefits of Lithium are:
CONCLUSIONS:
If you have a displacement boat which needs weight: use lead acid
If you have a racing yacht and a big budget: use lithium
AT THE MARINA = plug in to shore power 240V
ON A TRAILER = plug into the mains at home 240V
ON A SWING MOORING = use solar panels / (wind)generator
ON BOARD = HYBRID VERSION = engines recharge batteries