Star-Lord, Electric Trawler Conversion

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
What I think will work, and will provide a lot of the benefits of a 100% electric system, is a series hybrid diesel electric. If you run an 80 kWh battery (ie Tesla Model S long range) with a repurposed EV motor (150-300hp), you could have both good cruise range and the ability to motor out of tight situations at higher speeds. But you'd be dead in the water if you needed to use more power more frequently, so I wouldn't be comfortable with that trade off. Hence the addition of a diesel engine, perhaps fitted roughly where and how the factory diesel was, but spinning a genset instead of the prop. That genset would be charging the battery pack and running at max efficiency, since it'd be under consistent loading. Of course, the diesel could be off on slow cruise days, so you're running silently. Plus, dropping anchor with a full battery means you can run air conditioning all night without the thrum of a genset, cook with induction, and even heat with electricity, which means no propane on board either.


This comes up frequently, and a few have been built. If improved fuel efficiency is what you are after, this approach is a net loss, not a net gain over a conventional diesel+gear+prop. The recreational boats I know of that were built as diesel-electrics only lasted a short time before being converted to conventional drive, where they live happily ever since.
 
This comes up frequently, and a few have been built. If improved fuel efficiency is what you are after, this approach is a net loss, not a net gain over a conventional diesel+gear+prop. The recreational boats I know of that were built as diesel-electrics only lasted a short time before being converted to conventional drive, where they live happily ever since.


Absolutely agree. This can’t be about miles per gallon underway. I’m not sure that it’s impossible to increase efficiency beyond a traditional diesel power system, but that’s a question that’s better answered in the nautical world with, if you’re really concerned with efficiency, sails, anyway.

No, my goal for such a system would be increased MTBF and efficiency/flexibility at anchor. Being able to run ship mechanical systems silently at anchor for, potentially, an indefinite period, is a huge boon that gets lost in conversations around fuel burn underway.
 
. Being able to run ship mechanical systems silently at anchor for, potentially, an indefinite period, is a huge boon that gets lost in conversations around fuel burn underway.

Just because something runs on batteries does not make it quiet.
 
No, my goal for such a system would be increased MTBF and efficiency/flexibility at anchor. Being able to run ship mechanical systems silently at anchor for, potentially, an indefinite period, is a huge boon that gets lost in conversations around fuel burn underway.


If what you are after is "normal" electrical power at anchor without running a generator, that is very achievable. I would call it a hybrid "house" power system (as opposed to a hybrid propulsion system). A good setup of batteries and inverter can very easily solve this problem. Throw in so solar, and it gets even better. Plus LFP batteries make it several times better than it has been historically with lead.


Sizing everything is key, and keep in mind that there is a big jump in required capacity and power management if you also want to run HVAC. As a result, few people do it, but it's definitely possible.
 
Back
Top Bottom