[C320-list] Re Solar Panels

[Graeme Clark]

Scott

Your last comment made me laugh!

Yes you’re right about the potential degradation of boom shading and as you say the type of panel has a bearing on this. 

I chose a backwired flexible panel so we can safely walk on it (although try not to!) and after it arrived I jury rigged it at home to see the effects of shading. 

I think the biggest issue is whether the individual cells are wired in series or parallel. I think mine is wired in “banks” of several cells in series paralleled to the next bank

The outcome was surprisingly little degradation of output. I find that the boom is far enough away that it isn’t really deeply shading the panel. A cell can still “see” lots of bright sky even when shaded from the sun itself. Maybe not enough to generate much power but enough to stop the cell becoming a resistor!

But yes obviously it is better to have an unshaded location. I wasn’t “pushing” the underboom location so much as pointing out what performance you could expect if you choose to use it!

Graeme

Sent from mobile: please excuse typos etc.!


> On 11 Jun 2019, at 23:25, Scott Thompson <surprise at thompson87.com> wrote:
> 
> The problem with that location is that it is under the boom, so it likely is shaded when the sun is most directly overhead. Even a small amount of shadowing can reduce output significantly, depending on the shape and position of the shadow and how the individual cells are wired. For example, I've noticed that the shadow of a nearby mast can cut output to zero even though it covers only a small amount of my solar array. This is why I went with a location on the bimini aft of the boom, and am seeing significantly better performance than you report.
> 
> BTW, I most appreciate our bimini when it is raining! It might be just the thing for Britain.
> 
> Scott
> 
> 
>> On 6/11/2019 6:55 AM, Graeme Clark wrote:
>> Tom
>> 
>> Obviously the performance of a solar panel will depend upon how much light falls on it! That in turn will depend on where you site it (in other words whether it gets shaded and if it is square-on to the sun) and the weather conditions where you keep the boat!
>> 
>> However it might be helpful for you to know that having sited a 100w panel on the sliding hatch cover forward of the mainsheet traveller (which was a perfect fit) and using an MPPT controller, the very best we get from the panel when it is in full sun and unshaded is about 4amps at about 13v (in other words 52W or 52% of the ‘rated’ output). I think you would need very bright light that was absolutely square-on to the panel to better that.
>> 
>> Our refrigerator takes about 6 amps when it is running but of course it cycles on and off so I think probably only averages 3 or 4 amps depending how hot the climate and how often you open the door!
>> 
>> The weather here in Britain is such that we don't really need a bimini, so my choice of siting was based around the options available without the cost of building a stainless steel support over the cockpit just for the panel(s)
>> 
>> The real benefit - in my view - is that it’s “always working”, even when the light is poor. I know that if we have stayed aboard overnight and had the lights on and other electrical loads,  by the time we are up and moving about the next morning (we aren't early risers generally) the panel has already put a whole lot of power back into the battery.
>> 
>> Although the 100w panel isn't enough for the boat to be  entirely self sustaining it really takes the edge off worrying about power consumption. Yes, you can still flatten your batteries if you don't think about what you're doing but you can go much much longer between needing to motor or hook up
>> 
>> Hope that helps
>> 
>> Graeme
>> “Jaskar”, 366, 1996. UK
>> 
>> 
>> 
>>> On 11 Jun 2019, at 07:09, Utility Email <kswanson123 at comcast.net> wrote:
>>> 
>>> Tom,
>>> 
>>> Last summer I installed a 125W Solbian Solar panel on the Bimini of our Mark II with Fastex fasteners so it can be easily mounted and removed when the Bimini is deployed.  The stainless steel Fastex fasteners are very durable as they are typically used with convertible tops.  We don’t have or use an inverter aside from a small 12 automotive plug type of one from time to time.
>>> 
>>> We have a loaded 2007 C320 MK II model (similar to yours) with refrigeration in the ice box as well as the front loading WAECO refrigerator.  I installed a Genesun MPPT solar controller directly wired to the battery (fused of course) through our Xantrex Link Pro battery monitor so we can see the amps generated.  It works great.  I also installed the solar wiring with a Hella 12 volt plug in the stern near the shore power inlet so the panel can be removed and stowed easily under the after berth.  We connected everything with loomed wiring and A4 connectors.  When deployed or stowed, you don’t even know the 125 W panel is there.
>>> 
>>> The best part is that now instead of having to charge the batteries with shore power or morning every three days, we can go for a week without needing to charge if we are judicious about the refrigeration that we use.  I also upgraded all of our lighting, and we won’t use the icebox refrigerator (but still use the front opening refrigerator) while at anchor to reduce electrical demands.  We love the solar panel and the electrical independence and freedom it provides.
>>> 
>>> Check out our install photos on our C320IA website.
>>> 
>>> https://c320.org/mediagallery/album.php?page=1&aid=293
>>> 
>>> Have fun with your install.  I used a lot of advice from the Compass Marine website.
>>> 
>>> Dave Swanson
>>> S/V Emily Ann
>>> 2007 C320 MK II, No. 1107
>>> Mukilteo, WA
>>> 
>>> Dave
>>> 
>>> 
>>> David B. Swanson, P.E., S.E.
>>> Principal, LEED AP, F. SEI
>>> Executive Vice President
>>> 
>>> Reid Middleton, Inc.
>>> Engineers | Planners | Surveyors
>>> 
>>> Mobile:  (425) 508-7971
>>> 
>>> California Office
>>> 13220 Evening Creek Drive, Suite 115
>>> San Diego, CA  92128-4103
>>> Office: (858) 668-0707  | Fax:  (858) 513-2296
>>> 
>>> Washington Office
>>> 728-134th Street SW, Suite 200
>>> Everett, WA  98204
>>> Office: (425) 741-3800 | Fax: (425) 741-3900
>>> 
>>> www.reidmiddleton.com
>>> 
>>> Alaska | California | Hawaii | Washington
>>> 
>>> 
>>>> On Jun 10, 2019, at 6:24 PM, Tom Grass <tgrass462 at gmail.com> wrote:
>>>> 
>>>> Need advice on solar panels and regulators.  We are thinking of installing
>>>> some panels on Bucket List.  How many watts did you install?  Did the
>>>> install integrate well with your inverter?  Where did you mount the
>>>> panels?   Was the wiring a problem?  Any advise is appreciated.  Tom Grass
>>>> SV Bucket List. 2008 Catalina 320 MK II. #1135.
>>>> 
>>>> On Sun, Jun 9, 2019, 11:51 AM Jack Brennan <jackbrennan at bellsouth.net>
>>>> wrote:
>>>> 
>>>>> Well, I’m finally done with replacing the cabin sole with Lonseal teak and
>>>>> holly laminate. It was a success, but I have to say it was the most
>>>>> meticulous, unforgiving project I’ve taken on in three major refits of
>>>>> sailboats.
>>>>> 
>>>>> Some notes for anyone contemplating this project:
>>>>> 
>>>>> • If I had to do it over again, I would choose the solid teak pattern.
>>>>> Lining up the holly stripes is extremely difficult and time consuming.
>>>>> Remember, there are five hatch covers for the bilge and six separate floor
>>>>> sections in the cabin …
>>>>> • Thickened West System epoxy worked great. I mixed four separate batches
>>>>> to keep it from hardening. First the V berth floor, then the forward cabin
>>>>> area, followed by the large port and starboard sections in the rest of the
>>>>> cabin.
>>>>> • An expensive, really sharp utility knife is your friend. With a little
>>>>> practice, you can cut extremely accurate lines in the laminate if you take
>>>>> your time.
>>>>> • Even if you plan on cutting a new underlayment for the laminate, be
>>>>> careful to protect the old stuff when you remove it. Making your own
>>>>> pattern without them would be very time consuming.
>>>>> • On my 320, small screws through the laminate hold the floor underlayment
>>>>> to the subfloor. I chose to continue doing this, and it made it much easier
>>>>> to cut and glue down the laminate. I would take up a couple of screws, lay
>>>>> down the glue and rescrew the laminate down to the subfloor.
>>>>> • Lonseal comes in six-foot-wide sections. Ten feet, costing about $400,
>>>>> is plenty.
>>>>> • Lastly, if you have a fat bank account, this really is a project left to
>>>>> a floor professional. I did it myself to stretch my boat budget and because
>>>>> I’m retired with plenty of time. My guess is that it would cost 3K or so,
>>>>> based on $800 in material and $2,200 in labor.
>>>>> 
>>>>> Jack Brennan
>>>>> Sonas, 1998 Catalina 320, no. 528
>>>>> Tierra Verde, Fl. Dolphin Cruising Club of Tampa Bay.
>>>>> 
>>>>> 
>>>>> Sent from Mail for Windows 10
> -- 
> Scott Thompson
> Surprise, #653
>