Re: Solar Panels on Bimini with Split Backstay
Out of curiosity I took a look a 8 days of solar output by panel. The whole time the boat was in a slip facing more or less South. Port panels would get morning sun, but a bit limited by a large powerboat to the east. The radar pole is on the port side, which in this case is also the north side. The difference in out put for each panel is pretty negligible. With the starboard panel having a slight advantage, probably due to shading by the powerboat to port. Overall the differences amounted to about 2-3%. There was a couple of outliers that could be due to weather, since this is a retrospective study, I don’t have the climate data readily available.?
The panels are 2 150 watt Solar Panels with independent Victron controllers, mounted flat over the bimini. The data is from late February at about 31°N latitude. For most (all?) of the days we were living aboard.
Dave Second Star S362 #113 Fair Haven, NY/Lake Ontario
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On Mar 2, 2025, at 12:04?PM, Randy Drummond via groups.io <SVReleaseMe@...> wrote:
Yes Everything Dave said. One reason I put another panel on the davits was to surround the radar poll. In the worst case scenario there are always at least two panels in full sun. When the radar dome covers a good portion of a panel it does cut it down a good bit. The back stays really are not noticeable. I have noticed during the middle of the day with high sun, the angle of the sun to the panel makes more of a deference than I would have thought. My two panels on the Bimini are angled slightly outboard and I can see a difference in output when the sun angle slightly favors one side or the other. This has lead me to believe that on average flat is better.?On Mar 1, 2025, at 12:53?PM, David Lochner via groups.io <davelochner@...> wrote:
Tim,
This is where quality and good design come into play. A panel can be designed to be less affected by shading by how the cells are wired and the quality of the cells.
We have 2 150w Solara panels mounted over the bimini. The split backstay has little discernible effect on the power output. The radar pole has some effect, but I’ve never taken the time to figure out how much, too much work and too many variables to account for. When I look at the daily out put of both panels they are very close to being even. When planning the design expect to get about 3x the nominal output on average; a 100w panel will average 300wh of power. Again, better quality and more efficient panels will tend to do better. Earlier this week my panels were producing a little over 500wh of power each under clear blue skies at ~30° N in late February. In summer they have produced over 600 wh a day each. Total panel output will also depend on battery type and charge state. With LFP batteries the panels stay in the bulk stage for much longer. With LA batteries their output would go in absorption and put out less current.
Another advantage of higher quality panels is smaller size. The Solara’s were 3 or 4” narrower than similar panels from other brands.?
Dave Second Star S362 #113 Fair Haven, NY/Lake Ontario
<9FCE91F8-92D1-4B86-AA1B-47EE394D5163_1_105_c.jpeg>d On Mar 1, 2025, at 11:32?AM, Tim Sowerby via groups.io <tim.sowerby2@...> wrote:
With a split backstay, is there a concern about shading from the stay itself? ? (There's also an issue with shade from pole mounted radar installations.) ? I understand that some panels have substantially decreased output with very moderate shading whereas others are designed to be shade tolerant. ? ?In many ways the bimini seems like the best place to install flexible panels being out of the way and having less shade than the dodger. ? Considering the number of bimini installations out there, I'm beginning to think that shading from the backstay is more theoretical and real. ? Perhaps those with split backstays and bimini might comment. ?Is backstay shading a valid concern? ?Are there specific panel arrangements i.e. four 50W panels with separate MPPT controllers vs two 100 W panels with a single controller preferable? ?Are there specific panel brands/models that are more shade tolerant. ? ? Tim
Tim Sowerby
White Rose S426?
Sausalito CA ?
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Re: Cuttyhunk Rendezvous Summer 2025
Second half of August works best for me.
?
Many thanks,?
Carter Brey
T40 Lyra
City Island, NY
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I will find out what bottom paint the Marina in Coruna is using and will let you know .....
-- Gerald (Jerry) Brecher SIRACH 1982 Sabre 38 MK I Home port?Gloucester, MA currently lying?Coruna, Spain
488 Pleasant Street
North Andover, MA 01845 USA
mobile: 617-510-5133
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Re: Cuttyhunk Rendezvous Summer 2025
Moorings are first come basis and during summer it fills up very early both inside and outside the pond. If winds are SW anchoring outside is good but north winds are no fun at anchor outside pond Mitchell Sogin IPhone 5085661468
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On Mar 2, 2025, at 7:01?AM, Nancy & Bruce via groups.io <alcyone386@...> wrote:
? Yes, I am interested. August or September would be best for me. Thank you for thinking g of doing this.
Sincerely?
Bruce Hamilton? Sabre 386 #295 On Sat, Mar 1, 2025, 5:36?PM Roger Kuebel 362#150 Padanaram, MA via <rogerkuebel= [email protected]> wrote: I'm working on organizing an all-Sabre rendezvous in Cuttyhunk (Buzzard's Bay) this coming summer.? If anyone is interested in joining, let me know.
--
Roger Kuebel
Restless
S362#150
Padanaram, MA
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Re: Solar Panels on Bimini with Split Backstay
Yes Everything Dave said. One reason I put another panel on the davits was to surround the radar poll. In the worst case scenario there are always at least two panels in full sun. When the radar dome covers a good portion of a panel it does cut it down a good
bit. The back stays really are not noticeable. I have noticed during the middle of the day with high sun, the angle of the sun to the panel makes more of a deference than I would have thought. My two panels on the Bimini are angled slightly outboard and I
can see a difference in output when the sun angle slightly favors one side or the other. This has lead me to believe that on average flat is better.?
toggle quoted message
Show quoted text
On Mar 1, 2025, at 12:53?PM, David Lochner via groups.io <davelochner@...> wrote:
Tim,
This is where quality and good design come into play. A panel can be designed to be less affected by shading by how the cells are wired and the quality of the cells.
We have 2 150w Solara panels mounted over the bimini. The split backstay has little discernible effect on the power output. The radar pole has some effect, but I’ve never taken the time to figure out how much, too much work and too many variables to account
for. When I look at the daily out put of both panels they are very close to being even. When planning the design expect to get about 3x the nominal output on average; a 100w panel will average 300wh of power. Again, better quality and more efficient panels
will tend to do better. Earlier this week my panels were producing a little over 500wh of power each under clear blue skies at ~30° N in late February. In summer they have produced over 600 wh a day each. Total panel output will also depend on battery type
and charge state. With LFP batteries the panels stay in the bulk stage for much longer. With LA batteries their output would go in absorption and put out less current.
Another advantage of higher quality panels is smaller size. The Solara’s were 3 or 4” narrower than similar panels from other brands.?
Dave
Second Star
S362 #113
Fair Haven, NY/Lake Ontario
<9FCE91F8-92D1-4B86-AA1B-47EE394D5163_1_105_c.jpeg>d
On Mar 1, 2025, at 11:32?AM, Tim Sowerby via groups.io <tim.sowerby2@...> wrote:
With a split backstay, is there a concern about shading from the stay itself? ? (There's also an issue with shade from pole mounted radar installations.)
?
I understand that some panels have substantially decreased output with very moderate shading whereas others are designed to be shade tolerant. ? ?In many ways the bimini seems like the best place to install flexible panels being out of the way and having
less shade than the dodger. ? Considering the number of bimini installations out there, I'm beginning to think that shading from the backstay is more theoretical and real.
?
Perhaps those with split backstays and bimini might comment. ?Is backstay shading a valid concern? ?Are there specific panel arrangements i.e. four 50W panels with separate MPPT controllers vs two 100 W panels with a single controller preferable? ?Are
there specific panel brands/models that are more shade tolerant. ?
?
Tim
Tim Sowerby
White Rose S426?
Sausalito CA
?
--
Randy Drummond
Dazzle S38 mk2 206
Miami
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Re: Cuttyhunk Rendezvous Summer 2025
Yes, I am interested. August or September would be best for me. Thank you for thinking g of doing this.
Sincerely?
Bruce Hamilton? Sabre 386 #295 On Sat, Mar 1, 2025, 5:36?PM Roger Kuebel 362#150 Padanaram, MA via <rogerkuebel= [email protected]> wrote:
I'm working on organizing an all-Sabre rendezvous in Cuttyhunk (Buzzard's Bay) this coming summer.? If anyone is interested in joining, let me know.
--
Roger Kuebel
Restless
S362#150
Padanaram, MA
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Re: Cuttyhunk Rendezvous Summer 2025
Roger,
I am also interested in attending. ?Mid-late July would work for me. ?What will the mooring situation be?
Sounds like it will be a fun time. ?Looking forward to it.
Don Fleming?
Duet
S-38-1 #77
Hudson River
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Early to mid July
Changes in Latitude
1988 Sabre 42 #38
Guilford, CT
-------- Original message --------
From: "Roger Kuebel 362#150 Padanaram, MA via groups.io" <rogerkuebel@...>
Date: 3/2/25 9:15 AM (GMT-05:00)
Subject: Re: [SabreSailboat] Cuttyhunk Rendezvous Summer 2025
Wow! I wasn't expecting so much interest!? This is great.? I was planning on picking a date based on when interested people are available, but I don't want to jam up the chat board with back-and-forth, so if everyone who is interested could reply just
to me with the dates that work for them I will try to figure out the best dates.
--
Roger Kuebel
Restless
S362#150
Padanaram, MA
|
Re: Cuttyhunk Rendezvous Summer 2025
Early to mid July
Changes in Latitude 1988 Sabre 42 #38 Guilford, CT
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-------- Original message -------- From: "Roger Kuebel 362#150 Padanaram, MA via groups.io" <rogerkuebel@...> Date: 3/2/25 9:15 AM (GMT-05:00) Subject: Re: [SabreSailboat] Cuttyhunk Rendezvous Summer 2025
Wow! I wasn't expecting so much interest!? This is great.? I was planning on picking a date based on when interested people are available, but I don't want to jam up the chat board with back-and-forth, so if everyone who is interested could reply just to me with the dates that work for them I will try to figure out the best dates.
--
Roger Kuebel
Restless
S362#150
Padanaram, MA
|
Re: Cuttyhunk Rendezvous Summer 2025
Wow! I wasn't expecting so much interest!? This is great.? I was planning on picking a date based on when interested people are available, but I don't want to jam up the chat board with back-and-forth, so if everyone who is interested could reply just to me with the dates that work for them I will try to figure out the best dates.
--
Roger Kuebel
Restless
S362#150
Padanaram, MA
|
Re: Cuttyhunk Rendezvous Summer 2025
Always enjoy Cuttyhunk.? And I'm with Carter Bray and Jim Starkey. Sapphire usually has a selection of fine rum on board.
Cheers. Fair winds, Mike
~~ _/) ~~ svSapphire Sabre 402 Atlantic Highlands, NJ
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Re: Solar Panels on Bimini with Split Backstay
I hear these guys have a lot of experience with solar and can probably give some solid advice.?
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Carter Brey
Jerry Brecher
Eugene & Maureen
Wrtiverton
Michael Friedman