Looking for help with Cummins 6CTA (8.3 liter medium duty diesel)

[Stein]

You might get 95-96% efficiency when running a motor from a battery.  That's what some EVs get but they are highly engineered and purpose built motors and drives, I have no idea what the marine industry uses.

The larger savings would be from a battery you charge from shore power, but the electricity rates in AK at the marina are likely high just like anything else at a marina.

[Skillet]

You might get 95-96% efficiency when running a motor from a battery.  That's what some EVs get but they are highly engineered and purpose built motors and drives, I have no idea what the marine industry uses.

The larger savings would be from a battery you charge from shore power, but the electricity rates in AK at the marina are likely high just like anything else at a marina.

We're pretty high on the electricity in Sitka, but not as different as you might think at roughly $.215/KWH for summer rates.  Outpost towns can easily double that.

The issue is what a full charge really does for you in the fishing game.  For a few hour cruise around the area, some sightseeing, whale watching, maybe an afternoon fishing trip, etc., it would work great.  But for commercial fishing, where we are only tied up long enough to an area with an electrical supply to charge depleted batteries a few times season, it couldn't be the plan.  We definitely need onboard charging capabilities.

[Skillet]

Final update on this saga-

The Cummins NW guys were great throughout this.  They sent a new flywheel and starter on their dime and offered to send techs to fix - but our commissioning schedule and their schedules didn't align. So we went ahead and split the engine and gear, and swapped the parts as soon as we could overnight. It was a thrash, but we got it done. Engine fired up and was running great by mid-morning.  Turns out the flywheel was some oddball unit that nobody is really sure how it ended up on the engine.

I was on one of the commissioning runs to test the whole system.  The run silent mode (electric only, no pumps running) is pretty impressive.  You can hear every pulse of the prop passing near the hull.  However, when fishing, the pumps will be running - and that hydraulic pump hum is the same.

There are definitely some bugs to work out in terms of programming and system logic. They're out doing a subsistence longline set for black cod today to test it all out while running gear. 

Overall, my experience with this has been that it's a fascinating project, but I still cannot see how the ROI could ever pencil in our applications.  I hope I'm proven wrong for my friend's sake.

Thanks for the help and interest in this, foks -