Shaft generator

Aloha Steve and Linda,
We are building a 65′ Catamaran and trying to get as much of our electricity needs from solar and hydro. We chose a Duogen turbine but so far haven’t found a way to install it in a cat. Then I read that you used a shaft generator in one of your vessels in your cruises around the world. Can you tell us the pros/cons of the system and if it could be installed in a Cat. How much power should we expect from the shaft generator? we are running a 24V system in our boat.
Mahalo for your help and safe sailing.

With a cat and all the deck/house area I would opt for solar instead of a shaft generator which is draggy (you need a fixed prop) and noisy. Lots of details on this in our Offshore Cruising Encyclopedia.

Posted by Steve Dashew  (February 19, 2010)

2 Responses to “Shaft generator”

  1. Conceicao Says:

    Thank you so much for your prompt reply. The problem with the solar is that output is much reduced by the shade of the boom and sails. Hydro produces so much more, reliable, so long as you are on the move. We will check you Offshore Cruising Encyclopedia.
    Mahalo again, Conceicao

  2. Steve Dashew Says:

    One of the keys to charging under way is how often the engine is used on a passage. Our experience is that on most passages the engine is run in light airs almost daily, even in the trades. That is sufficient charging for the day, in which case why drag the prop (or have an auxilliary prop). We fitted charging shafts to three or four boats (one for ourselves) and all were eventually removed. While sailing at eight knots the output was in the range of 25/35 amps at 24VDC (from what may be faulty memory – OCE will have the data).