Re: Repowering with an electric engine?
50nm is great range? You can easily sail farther than that in a day.
I think that the practicality of an electric motor for a sailboat depends on how you use the boat. I do a lot of cruising on vacation time, so I do need to get home on schedule. I can easily sail 70nm in a 12 hour day and do 1-2 week cruising vacations. I need to know that if I leave in a period of strong wind that I can motor back if necessary. That doesn't mean motoring at 3 knots (half of my normal cruising speed) or on short days.
If I were not going back to work and sailing around the world without a schedule it would be easy to operate motorless or with a short capacity electric motor. As someone with regular employment and fixed vacation schedules I don't see any option other than diesel or gasoline that is practical.
If I sailed on a lake or only used the boat for short day sails then electric would be a great option.
boats that I sail on regularly: Pearson 28-2, Rondar 505, Yankee 30, Blanchard Junior