I've always had the point of view that currently the most efficient way to store energy is in fossil fuel, AKA diesel. My boat doesn't have an inverter. We're perfectly fine running the generator(s). The engine room is insulated enough where we can barely hear the slight hum of them running. I never really penciled out the cost of an inverter bank, but with all the talk of Tesla's new battery it got me thinking. Is Tesla's new battery a game changer in the yacht world? How does it compare cost wise to building your own lead acid bank? How about application and installation... does lithium ion present issues in the marine environment? What are your thoughts?