After having cruised part time for several years and now full time for several months, we have compiled a list of advantages and disadvantages for electric propulsion. This list is not meant to sway you towards or away from electric propulsion, but merely to educate you on its potential advantages and drawbacks that way you can make the most informed choice for your own yacht.
Let's start with the disadvantages, as people who have diesel motors tend to pick on this system quite intensely; later we will go over the advantages.
Range is limited to the size of the battery bank.
Weight of the battery bank can add up quickly.
Range can be supplemented by using a generator, but your speed will be limited by the size of the battery charger.
Electronic components on a boat are prone to corrosion caused failure.
Parts are not readily available, as they are not common components.
Skilled and qualified labor is hard to find.
Battery technology has a long way to go to provide the amount of range of a fuel tank.
You can't charge your batteries by running the motor.
Deep discharging is damaging to the batteries.
When it fails, the culprit is not always obvious.
Nearly no noise.
It is very small in size.
It is light weight.
It starts up immediately without needing to warm up.
There is no exhaust smell.
No risk of carbon monoxide poisoning.
There is no need to winterize the motor.
It provides instant torque and has very fast throttle response.
You can install and service the motor yourself with basic tools.
There is no risk of oil leaks or oil spills.
Enviromentally friendly since it uses no oil or fossil fuels.
You can recharge it with solar panels and wind generators.
It acts as a hydrogenerator when sailing.
The motor is air cooled so you don't have to worry about clogged strainers or sand in the waterpump.
No fuel filter to clog.
Less moving parts to fail.
Nearly maintenance free (only two Zerk fittings to grease once a year).
No oil changes needed.
You don't have to worry about fuel quality or water contamination in the fuel.
You don't have to polish your fuel.
Long and short term costs are less:
The cost of replacing dead batteries is less than the cost of fuel consumed over the same distance.
You will save a lot of money on fuel costs.
The electric motor is cheaper to buy and the parts are also innexpensive when compared to a similarly powered diesel motor.