Re: [Amel Yacht Owners] Solar Energy System

Bill Kinney <greatketch@...>


Angling solar panels  to the sun is not a panel technology issue, it is simple physics.  The benefit has not changed.  It is true that some panel manufacturers make use of internal reflections, back side generation, and such, it makes a VERY small difference in overall output if the panel doesn’t track the sun.

When the sun is at 45 degrees the panels only “see” about 70% of the incident solar radiation they do when at 90 deg. What they don’t “see” they can not generate power from.  That’s physics and hasn’t changed.

The hard part is deciding if it is worth it to mount adjustable angled panels on a moving platform like an anchored sailboat.  I don’t have an easy answer for that one...

Bill Kinney
Harmonie, SM #160
Cape Canaveral, Florida

On Mar 9, 2016, at 12:45, 'Bill & Judy Rouse' yahoogroups@... [amelyachtowners] <amelyachtowners@...> wrote:


Regarding the size "gravitation," I think it is because what will fit on liferails and what will fit on an arch.

Regarding the rotation to the sun, it is my understanding that with modern solar panels that this is not as important as in the past, albeit some benefit still exists. That benefit needs to be quantified before you go to a great deal of trouble and expense. You should check this out with a reliable other words, not Cruisers Forum. There has got to be a good, knowledgeable and honest source for this information, although I do not know where to go...maybe someone else can refer you.

BeBe 387

On Wed, Mar 9, 2016 at 5:07 PM, Bill Kinney greatketch@... [amelyachtowners] <amelyachtowners@...> wrote:


The reason the 140 W panels are popular on boats, is they are the largest standard panels that easily fold flat against lifelines.  Larger panels start to get too wide to easily store vertically inside the standard lifeline height.

If you are shopping with eMarine for panels in the 320 W size range, you might consider the LG panels.  They have a higher efficiency than the Kyocera panels, hence a bit smaller, and the price is attractive.

Bill Kinney
Harmonie, SM#160
Cape Canaveral, Florida

On Mar 9, 2016, at 11:59, sailor63109@... [amelyachtowners] <amelyachtowners@...> wrote:

I'm considering adding solar panels and an MPPT Controller to the boat.  I'm wondering why everyone seems to gravitate toward the 100 to 140 watt panels (these have 36 cells).  Manufacturers also make larger (by wattage and size) 260 to 325 watt panels (having 60 and 80 cells respectively).  The Kyocera 140 watt panels sell for $2.12 per watt and the 325 watt panel sells for $1.31 per watt (about 62% of the 140 watt panel, prices from  For the same wattage I think you'll need the same controller (especially if you wire the panels in series).  If you wire the 140 watt panels in parallel the total voltage would be less so you would save marginally on the controller.

The reason I'm asking is I'm planning on mounting them on poles at the stern quarters with rotating mounts so they can be positioned.  The only real downside that I know of with the 325 watt panels would be their size and weight.  60 pounds is a lot to dismount if heavy weather was expected (I wouldn't think this be too much of an issue).  I'm still researching whether it makes sense to pole mount these 65" by 52" panels.  Kyocera also makes a 260 watt panel (60 cells) that's only 41 pounds and 65"x39".  That would seem easier on me and the pole!

Any thoughts or experiences with pole mounts and these larger panels is appreciated.

Wanderer, SM#477

Join to automatically receive all group messages.