Solar Panel Pole Mount - Flexible Panels

robalex117

Super Anarchist
Looking for a mount like shown in the picture.  I like these panels because they are light.    My other opton is to get some carbon tubes and start making something but it would be good to have something to start with.

IMG_2291.jpeg

 

slug zitski

Super Anarchist
4,976
774
worldwide
Many of the minis that do the mini transit have these.  It won't be a set and forget but looks like it is holding tight in that picture.  
Yup 

race boats are always a compromise 

you might try to stiffen the panel with a sheet of 4mm ply 

and make it easy to unplug and remove the panel when things get aggressive 

 

slug zitski

Super Anarchist
4,976
774
worldwide
Solar panels reduce output when they get hot 

When  backing  , reinforcing the rear side of the panel , you block ventilation to the back of the panel and the panel will run hot 

better to use a very robust backer then cut it out  in such a way.. …ventilation pattern ….that stiffness is  maintained , weight reduced ventilation achieved 

additionslly the single point , load concentration , panel attachment point  is poor engineering 

you must design the attachment to spread the load over a much larger area 

 
Last edited by a moderator:

robalex117

Super Anarchist
Solar panels reduce output when they get hot 

When  backing  , reinforcing the rear side of the panel , you block ventilation to the back of the panel and the panel will run hot 

better to use a very robust backer then cut it out  in such a way.. …ventilation pattern ….that stiffness is  maintained , weight reduced ventilation achieved 

additionslly the single point , load concentration , panel attachment point  is poor engineering 

you must design the attachment to spread the load over a much larger area 
That is a good point.  That is a nice job he did with the mount.  Maybe drilling a bunch of holes to let air circulate would help.  

 

ryley

Super Anarchist
5,380
581
Boston, MA
Let's put this in practical terms.

flexible solar panels come in at about -0.3%/degreeC above 25c. That's about 1% / 3degC. So for a temperature of say 40c, that's 15deg/3=5% loss on a panel that is 17 - 22% efficient. That's a pretty significant loss. I'd like to see some real-world monitoring that the panel surface is regularly getting that hot especially on a moving boat. I'm sure it happens, but what's the peak temperature and how long is at that peak? 

 

DDW

Super Anarchist
6,238
971
Let's put this in practical terms.

flexible solar panels come in at about -0.3%/degreeC above 25c. That's about 1% / 3degC. So for a temperature of say 40c, that's 15deg/3=5% loss on a panel that is 17 - 22% efficient. That's a pretty significant loss. I'd like to see some real-world monitoring that the panel surface is regularly getting that hot especially on a moving boat. I'm sure it happens, but what's the peak temperature and how long is at that peak? 
Unfortunately, if it is sunny no way those panels will be only 40c. They get way too hot to touch. Real world example: the array on my house is rated at 4.5kW. When the sun hits it on a cold morning (at a shallow angle) I've seen as high as 5.2kW. Mid day, with the sun directly on them in the summer, can be as low 2.5kW. Fro the flexible panels on the boat it is much harder to quantify as they get shaded by different things, are pointing different directions, etc. - but in the sun, still too hot to touch. 

 

ryley

Super Anarchist
5,380
581
Boston, MA
Unfortunately, if it is sunny no way those panels will be only 40c. They get way too hot to touch. Real world example: the array on my house is rated at 4.5kW. When the sun hits it on a cold morning (at a shallow angle) I've seen as high as 5.2kW. Mid day, with the sun directly on them in the summer, can be as low 2.5kW. Fro the flexible panels on the boat it is much harder to quantify as they get shaded by different things, are pointing different directions, etc. - but in the sun, still too hot to touch. 
ok, on your house I'm not surprised. I don't think any panel on my boat has ever gotten too hot to touch, or at least no hotter than the decks, and that includes going to and staying in Bermuda. Of course now that this is a thing, I'm going to do some measurements this summer of the rigid and flexible panels - the flex panels are on my dark blue dodger.

but ok, the math for 60c is 35deg/3 = 12% loss. significant, but not catastrophic.

 
Last edited by a moderator:

slug zitski

Super Anarchist
4,976
774
worldwide
ok, on your house I'm not surprised. I don't think any panel on my boat has ever gotten too hot to touch, or at least no hotter than the decks, and that includes going to and staying in Bermuda. Of course now that this is a thing, I'm going to do some measurements this summer of the rigid and flexible panels - the flex panels are on my dark blue dodger.

but ok, the math for 60c is 35deg/3 = 12% loss. significant, but not catastrophic.
On a small installation any loss is significant 

 

Ex Machina

Anarchist
570
213
New Zealand
Unfortunately, if it is sunny no way those panels will be only 40c. They get way too hot to touch. Real world example: the array on my house is rated at 4.5kW. When the sun hits it on a cold morning (at a shallow angle) I've seen as high as 5.2kW. Mid day, with the sun directly on them in the summer, can be as low 2.5kW. Fro the flexible panels on the boat it is much harder to quantify as they get shaded by different things, are pointing different directions, etc. - but in the sun, still too hot to touch. 
 
 
Last edited by a moderator:

Ex Machina

Anarchist
570
213
New Zealand
Unfortunately, if it is sunny no way those panels will be only 40c. They get way too hot to touch. Real world example: the array on my house is rated at 4.5kW. When the sun hits it on a cold morning (at a shallow angle) I've seen as high as 5.2kW. Mid day, with the sun directly on them in the summer, can be as low 2.5kW. Fro the flexible panels on the boat it is much harder to quantify as they get shaded by different things, are pointing different directions, etc. - but in the sun, still too hot to touch. 
 
I recently saw a a canvas Bimini cover at the local sail loft with a hole scorched in it from a flexible panel . Luckily the owner was onboard and caught it before it properly combusted . I thought flex panels fitted on canvas biminis were a lever solution but not anymore 

 

Max Rockatansky

Max Rockatansky
3,536
816
I know of many boats that burned to the waterline for many reasons. Without details, such as the quality of the panels or of the installation, or the age/maintenance, your assertion is not worth much.

 
Top