Good luck with retirement, I hope the year passes quickly for you. One day you will look back and realize that retirement was the best career move you ever made. Work isn't so bad until it interferes with sailing. That being said, I appreciate your sharing all this process with everyone here, as most of us are short on real world experience with electric propulsion. Many years ago I understood that the US Army, in their quest for alternative energy and drive systems, determined that the most efficient drive train was in fact just that, a train with diesel/electric power. Unfortunately, there are some peripheral issues for us sailors, the biggest being weight. For a barge however, it might be just the ting.
I'm still in love with the idea of electric propulsion, maybe Musk will turn his passion to sailing. My future plans are for long term cruising/liveaboard off the grid on a boat that is somewhat more weight sensitive, and that puts electric out of the running as I see it.