Join Date: Apr 2008
Location: On the SF Bay
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Hybrid power is a solution looking for a problem. The technology as applied to sailboats, needs time to mature at the very least. Yes, diesel subs and EMD offshore supply boats have been around for ages but the technology as applied to sailboats is very new. Diesel subs could only stay under water for so long, and then they had to return to the surface so their batteries could be recharged by a diesel engine. Ice breakers, locomotives and offshore supply vessels that use EMD systems have very large diesel engines attached to a very large generator whichis then attached to a very large propulsion motor...which amounts to a large percentage of a vessels displacement and a subsequent loss energy as heat energy. The application for sailing yachts is very different from the previous applications and this is the critical difference.
Converting mechanical energy to electrical energy, to then be used or stored and then converted back to mechanical energy is inherently very inefficient. Each time energy is converted, part of that energy is lost as heat energy. Even if a boat could be run purely off solar and wind energy, one must consider the increased number of batteries in terms of additional weight added to the boat and pollution to the environment in the process of making those batteries.
Another factor is sustained cruising, where within a 24 hour period, with a hybrid boat you are limited to the generators output minus your shipboard loads, minus the inefficiencies. Hey, stuff happens and the iron jenny becomes necessary for hours and sometimes days. An eight kW generator is the equivalent of 10.8 horsepower minus any inefficiencies in converting watts to mechanical energy and minus the shipboard load. With a 20 kW generator, the equivalent horsepower is 27.2 horsepower. Is it feasible to place a 20 kW generator aboard a sail boat that only needs less than a 27 horsepower engine for its propulsion?
Benthos Critters United.
Last edited by BenthosCritter; 04-27-2008 at 08:34 PM.