Comment by aaronax

It seemed to be the most DIY-friendly product line with a complete selection of things that I wanted. Plus very popular so lots of armchair experts out there in the related Facebook groups. :)

We have a 36 HP Yanmar 3JH2E so that would be about 27,000 watts. Now say that wanted to give up the ability to approach hull speed while motoring, maybe 1/2 of that would be OK. So call it 12,000 watts, or 1000 Ah in a 12V system to motor for an hour. Our batteries were close enough to $1,000 for 100Ah so it will cost you $10,000 to have enough batteries to motor for 1 hour.

The solar capacity to get you into the barest realm of running that motor or charging a sufficient battery bank would be 3000 watts...minimum. The most I have heard of on a 40-50 foot monohull is 2400 watts. A catamaran could get you there, but you will give up looks and be spending $100,000+ on panels, controllers, wiring, mounting, etc. And weight is crucial on a catamaran so bust out more cash to make it lightweight.

All this means that realistically you will have 1 hour or less of electric motor run time. I have only been sailing for 5 months so take this with a grain of salt, but I usually have somewhere to get to before dark and I also don't enjoy waiting days for favorable weather or inching along at 4 knots in crappy wind. And I like traveling on the Atlantic Intracoastal Waterway. I use the engine to keep our speed above 6 knots. So if I was to go with electrical propulsion I would put in a generator (probably a DC generator).

Sailing Uma has some YouTube videos about electric propulsion on their sailboat. Their style of travel is much different than mine. They sail a lot more!