Sorry. Links to offsite polls are against our forum rules, however asking the questions is just fine. As long as we stay within that rule, the conversation is welcome and probably going to gain you some interesting information.
BTW - this topic has been posted about before. It's probably worth the effort for you to do a search of the forum on alternative fuel, electric motors and such (if you haven't already).
***I did not know that. Thank you for telling me! I will certainly give it a look!
I think many (if not the majority) boaters are environmentally conscious. I would call myself a conservationist vs. an environmentalist as the terms normally get used today - but I'm constantly watching how I'm interacting with both the waters I boat and the wildlife I encounter (<== some of which is other boaters

).
How would you define conservationist vs. environmentalist? What types of things are you watching out for when interacting with the waters and wildlife? Air Pollution? Habitat Disturbance? Litter? Water Pollution? Do you consider any one aspect more important than another?
The adoption of electric trolling motors over the last few decades would suggest that use of electric would adopt quickly in boating applications were it made practical. Roscoe's point about "energy" and "bunkerage" for enough electricity is spot on.
What in your opinion would make it practical? What are the objections that need to be overcome specifically? What is an acceptable battery weight? What is an acceptable battery life and charge time?
I am

But, it's an issue of noise under load. At idle, most of my motors have been/are reasonably quiet. BUT, the minute you spool any of 'em up to speed they get considerably noisier. If an electric motor is going to be quiet but only push me at 5KTS, it's not all that valuable compared to a gas motor. If it'll push me at 35KTS and be really quiet, now you've got my attention.
I am really sorry, I don't know what KTS is. What if the electric motor could run on a single battery at 35-40hp and up to 80 with a double battery set up, and was still practically silent at full speed? Quiet enough that you could carry on a conversation at a reasonable volume level without the motor noise getting in the way?
Price will always be a driver - right now there are electric cars that are good vehicles; practical and energy efficient. But over a 5 year ownership, the cost savings is not substantial enough to move me from driving a 3/4 ton pickup truck (that I can buy at 1/4 the price) to a small four door electric car.
Is there any factor that could get you over the price objection? for example, you are comparing a small four door electric car to your 3/4 ton pick up truck. What if you could have an electric 3/4 ton pick up? (ie. the electric motor would perform just as well as the gas motor at the same hp level)
I'm a big fan of the Tesla, but can't make it practical enough to purchase.
Weight vs. output matters on nearly any boat. And I'm guessing that your motor won't really be the heavy part in many cases ... it's going to be the batteries that add all the weight. A small utility boat (fishing as an example) weight will be a bigger concern because I'll be carrying the whole thing in the back of my pickup and my buddy and I have to mount the motor every time we go fish in the river. Conversely, a bigger outboard on my 20 foot sport boat can be considerably heavier because I'm not going to take it off the boat if I can avoid it.
Let's say the electric outboard would weigh 70 lbs. How much would the battery have to weigh for the set up to be attractive for you?
How many HP will the motor turn out, and how long will the batteries last at 75% power?
I don't know. How many would it have to turn out, and how long would the batteries need to last at 75% power for you to consider it?
I wouldn't. But I would also contest that all "alternative energy" motors are more environmentally friendly. BUT I like alternative energy enough to consider it based on all sorts of factors - safety, power, performance, cleanliness, etc.