That's pretty cool James. I can see where that might make sense on a big sailboat where you've got heeling to contend with and enough stability to support such a rig. I imagine a single axis tilt that compensates for the boat's heel would give the biggest bang for the buck. On a relatively flat-running trawler or cat the benefits would be less dramatic.
I ran a few scenarios using the "PVwatts" calculator on the NREL.gov site.
http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/
For Los Angeles, averaged over the year, it shows about 1.5:1 difference between a full 2-axis tracking array and flat mounted array of the same watt rating. In mid summer it's under 1.3:1, in January it's about 2:1.
For my home state of Minnesota the difference between yearly averages is about 1.7:1. In August it's only 1.26:1, while in January it's 3:1. Not much sailing going on in MN in January though. I only need be concerned with the summer months where the difference is under 1.5:1.
Anyhow, from this kind of comparison I concluded that the complexity and top-hamper of a tracking array just isn't worth the trade, at least not on a lightweight, non-ballasted trawler like mine.
Jim
--- In electricboats@yahoogroups.com, "James" <james@...> wrote:
>
> We have just recently completed testing of our solar array which you can find on the website at
>
> http://www.propulsionmarine.com/electric/charging-sources
>
> SOLAR - The Propulsion Marine Solar Array Features:
>
> 2 x 225 watt Sanyo Panels for total of 450 watts at 90 Volts
>
> Midnite Solar Charge Controller
>
> Electric Actuator Lift Arm
>
> Electric Worm Gear Chain Drive to Rotate Pole
>
> Joystick Control
>
> Tracker Expected to be released soon.
>
>
> By Focusing on the sun, power developed is as high as 10 times more than if panels are mounted horizontally
>
> Kapowai is capable of obtaining 3 knots while motoring under power made directly from the solar panel.
>
>
> James
>
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