Return to Directory

Towed-Water-Generator

John MacDougall, Annie Laurie, #26

Well, unlike my other projects, I don't have real world results to tell you all about......Not yet anyway.....as my first use of this will be on my Atlantic crossing this summer, and I'll do my best to update you all (including new photos) when I can.

A week or two ago, I installed a Hamilton Ferris / Ferris Power "WP-200" Towed-Water-Generator, that can produce more than enough power when sailing at reasonable speeds to keep up with most all the electrical needs of an offshore cruising sailboat in the 45' - 50' range.

My estimates and calculations show that.....

This towed-water-generator, together with my 520 watts of solar panels, will allow my Annie Laurie to sail long distances (3000+ miles) for weeks at a time, without the need to use any fossil fuels (diesel fuel, etc.) to generate power / charge batteries......

With 24 hr/day use of Raymarine autopilot and instruments, refrig/freezer, VHF Radio, AIS receiver, lights, stereo, etc. as well as daily use of WeFax receiver, SSB / Ham Radio, Radar, etc....as well as use of my new watermaker (Spectra Ventura 150MPC) every few days.......

(Click on picture for full size)

Towed-Water-Generator

Here are some views of the WP-200 Water Generator Brochure,...

Towed-Water-Generator

...and a close-up of the power curve graph.

The graph shows outputs of:
5 amps @ 4 kts (24 x 5 = 120 a/h per day)
8 amps @ 5 kts (24 x 8 = 192 a/h per day)
11 amps @ 6 kts (24 x 11 = 264 a/h per day)
15 amps @ 7 kts (24 x 15 = 360 a/h per day)
19 amps @ 8 kts (24 x 19 = 456 a/h per day)

But, these are the factory numbers...... NOT, real world numbers.....

And, of course, you do NOT need to use it 24 hrs/day if it isn't needed, nor desired.....thereby allowing you tailor your power use / battery charging routines based not just on your personal tastes, but also taking boat speed (and wind conditions) and expected boat speed (and wind conditions) days from now, into account..... (You may have light air and slow speeds now, but forecasts/predictions show good wind and better speed in a day or two, so you use power now - and charge more in a day or two, when you've got lots of wind to spare.......or vice versa, could also be true.....)

My guess is that the actual output will be about 85% - 90% of the figures quoted.... But, even that is substantial......that's still more than 165 a/h per day when sailing at an average of 5 kts....and more than 200 a/h per day when sailing at an average of 6 kts.....assuming use 24hrs/day....

With typical prop / line drag forces slowing down a modern light displacement performance cruiser approx. 1/4 kt. (0.25 kts), it's a small price to pay for added electrical power.....and of course, you don't need to use it 24 hrs per day if it isn't needed, nor desired....

Towed-Water-Generator

 

Towed-Water-Generator

 

Towed-Water-Generator

 

Towed-Water-Generator

 

Towed-Water-Generator

 

Towed-Water-Generator

 

Towed-Water-Generator

I've got the unit mounted on the port side transom, between and just above, the dock water inlet and deck shower......

It has a sturdy white Marelon base that I've thru-bolted with 3 1/4-20 bolts and the generator yoke simply sits into this base and is secured in place by a set screw. There is a 75' length of line that attaches the generator to the propshaft and 5" dia prop. It is the spinning of this prop when the boat is making way that spins the generator, and hence makes electricity.....

I have it wired with a flush mounted, quick disconnect 2-cond. plug/socket (provided by Ferris Power, but one that I will change out for a heavier one next year, I think). From the plug/deck socket, I have a run of 10ga. wire to the Nav Station, where I mounted the Ferris Power amp meter and diodes BEHIND the upper aft Nav Station panel.....I will need to swing down this panel a little, to see this amp meter, but I have total monitoring of my batteries / charging from my SALT TM-500 battery system monitor, which is mounted out in the open on the lower forward Nav Station panel, so I doubt that this will present any problems.... (I still have some space available in the Nav Station panels, and hope to keep things clean and uncluttered....)

I WILL be taking some photos of this unit in operation..... BUT, the operational photos will not be available to view until I get back from the first part of my trip (in August).....

I hope you all enjoy.