I think the issue of drag with a towed generator is often overstated, it certainly hasn't been significant for me, and I sail a boat only 25 feet on the waterline... On a larger boat of 40' or so, loaded for cruising, I would expect it would be barely noticeable in the bigger picture...
It's certainly an intriguing idea, but the main problem as I see it, is that the potential market for such a system is likely to be pitifully small... Two of the most notable trends I'm seeing these days, are the proliferation of portable Honda generators, and ever-larger SUV dinghies powered by 15-25 HP engines... I don't think I've EVER
seen a Torqueedo in a place like the Bahamas, for example - they simply won't satisfy the demand that many of today's cruisers have to go far, and fast
, in their tenders...
The only way for such a hybrid system to make sense, is when used in conjunction with a minimalist approach to energy consumption on board... Unfortunately, the modern trends are quite the opposite, with today's boats being fitted out with a wide array of power-hungry gear - bow thrusters, electric winches, full-time use of laptops for navigation, and so on...
And, bottom line, many people also spend a considerable amount of their time underway, under power
, anyway... A LOT of people simply don't routinely use their boats in a way that really justifies such a system, seems to me...
Good points all, Jon. With the average cruising boat moving north of 40', the popularity of RIBs and high-pressure dinks (which can take 15hp outboards, so why not buy one?), nearly ubiquitous refrigeration, two hot showers a day, etc.... There's no demand for 'elegant' or 'clever.' Brute force suffices -- it solves nearly all problems. Or rather, it creates its own set of problems but those are broadly within the scope of the owner's competence.
Running the engine/genset two hours a day requires big tanks; s'okay, we got a big boat. Heavy electric use requires big batteries; see above. Or shore power -- we like marinas. Gasoline gennies need fuel; we have a thirsty gasoline outboard, so we carry 30 gallons anyhow. Easy. Running the engine to charge batteries shortens its life; but as you note, the majority of sailors motor rather than sail the majority of the time anyhow, so the electrical loads are not a determining factor in engine life. *shrug* It's how we live today. Not judging anyone's choices.
We, OTOH, just bought a small 30'er. Very small, compared to today's boats. Our refit budget is limited, stowage and tankage space is very hard to find, the engine is forty years old, and we chose this boat for its sailing qualities. Also, we expect to cruise in places where gasoline, diesel, water, and provisions may be hard to come by. Unlike, for instance, the Exumas -- where you can get anything, if your chequebook is large enuf.
So for us, elegance and cleverness still rate. We need gear that serves many functions. We need to minimize power and water consumption. The engine must be babied. And because we intend to sail the boat rather than motor, we need to take care that 'improvements' don't hinder its sailing ability -- hats, rather than full bimini. If we could finagle a hydro-gen/electric outboard combo, that would really work for our intended lifestyle. It would be a hugely attractive package. But such an item would not be easy to engineer, nor cheap.
(One advantage we have -- if you want to call it such -- is we live off the electric grid in the wilds of Wyoming. We drink rainwater and can deal with solitude and isolation. It's very hard for people coming from cities or suburbs to transition to a low-stimulation, minimalist lifestyle. Tho Chicky is going to want her some Internets, for sure.