Solar; Flex Panels for Summer Usage while traveling

[Sdpaddler50]

We need solar about 3 to 4 months per season, and only intermittently when anchored for 1 to 3 weeks, then back to a marina and a power cord.

I have a Gen, and need to run it every day for heating water and a few other things like cooking. We currently run the Gen about 3 hrs per day.

AGM battery bank is 1,000 Amp hrs and typical draw is around 5 to 15 amps with everything on and people aboard.

Overall Need: Some help from the sun for battery health, and reduce Gen run time.

I realize the ridgid panels are more efficient and durable, but the most practical available space we have is on top of a large canvas Bimini. I would take the Bim and panels down in the winter, so they would only be up there and exposed to the elements about 4 mos per year.

With a good controller/charger and a high quality flexible panel (as opposed to rigid for reasons described above) does this make sense for our noted use case?

Note: I have read through some discussions on flex panels, just starting a new thread as it relates to our situation.

[CaptainRivet]

Originally Posted by Sdpaddler50

We need solar about 3 to 4 months per season, and only intermittently when anchored for 1 to 3 weeks, then back to a marina and a power cord.

I have a Gen, and need to run it every day for heating water and a few other things like cooking. We currently run the Gen about 3 hrs per day.

AGM battery bank is 1,000 Amp hrs and typical draw is around 5 to 15 amps with everything on and people aboard.

Overall Need: Some help from the sun for battery health, and reduce Gen run time.

I realize the ridgid panels are more efficient and durable, but the most practical available space we have is on top of a large canvas Bimini. I would take the Bim and panels down in the winter, so they would only be up there and exposed to the elements about 4 mos per year.

With a good controller/charger and a high quality flexible panel (as opposed to rigid for reasons described above) does this make sense for our noted use case?

Note: I have read through some discussions on flex panels, just starting a new thread as it relates to our situation.

Have a look at these products, https://www.geminiproducts.net/concave-rail-mounts/
Solar makes always sense, cheapest quiet and reliable as soon as you have daylight, rocks if sun is out.

you can also put ridged bifacial panels on top of a bimini
I highly suggest to use bifacials rigid panels over expensive, unreliable and very low production semi flexible ones. They are really your last way out if nothing else fits or works. They also heat up quite strongly and reduce the life of the Bimini. It’s worth the additional effort to mount ridged ones on top of the Bimini.
Bifacials work with diffusion light and at sea you have plenty of it. So you get max out of the surface you have available

[sesmith]

When we had our canvas replaced last year, our canvas guy sewed zippers on the panels and on the bimini. We zip them on in the spring and zip them off in the fall. Prior to that, I used 3m dual lock. I did beef up the bimini frame and add battens over the bows under the fabric to better support the panels. I've been using Renogy flexible panels for 3 years with no issues.

[smac999]

If you run the gen every day anyways and often get to a dock to fully recharge there is no need for solar. Take a look at your ac charging instead. With 1000ah of agm you should have at least 200a of charging. That is 600ah a day charging at 3hrs if batteries are low.

If you are using ariund 10a. That’s 240ah a day. Or under 1.5hr gen time with proper chargers.

What are you currently charging with? And how big is your gen?

[Sdpaddler50]

Originally Posted by sesmith

When we had our canvas replaced last year, our canvas guy sewed zippers on the panels and on the bimini. We zip them on in the spring and zip them off in the fall. Prior to that, I used 3m dual lock. I did beef up the bimini frame and add battens over the bows under the fabric to better support the panels. I've been using Renogy flexible panels for 3 years with no issues.

I was also thinking of having my canvas guy sew them in to the Bimini, or another method to get them secure. I would also add some fore and aft struts to the Bim structure to help support the panel.

Reonogy and Solbian both appear to get good reviews in general. I talked to an installer who has done 3 sailboats with Solbian and he said they provided good customer support.

[Pete7]

Does the top of your trawler roof look like this?

If so use sticky velcro pads to hold down the solar panel to the roof. We have just removed it now because the panel failed, but 4 x 2" pads held down a 50w solar panel for 2 years through all weather all year round.

Take the panels off during the winter if you need to.

4 x 100A panels should give you 1.8Kwh during the summer.

https://www.amazon.co.uk/Double-Stic...Q%3D%3D&sr=8-5

[hlev00]

I mounted my Solbian panels on my Bimini using velcro lapels. I am very happy with the panels. The mounting method is very secure but is a bit awkward to mount them at the beginning of the season as the velcro always wants to attach itself before I have the panel lined up. To help with this, I us a large plastic trash bag around the panels. After they are in lined up, I pull the plastic bag off and the velco grabs on. I could have possibly used less velcro or oriented the hooks and loops differently so they don't catch when I don't want them to. I think SV Delos used clips or some other method to secure to their cloth bimini. Here is a write up of my solar.
https://juno423.blogspot.com/2020/08...th-photos.html

Harry

[sesmith]

Originally Posted by smac999

If you run the gen every day anyways and often get to a dock to fully recharge there is no need for solar.

That may be true, but everyone else in an anchorage will be SO glad you installed solar.

Did I mention how much I hate generators? 😁

[sailormed]

Flexible panels are flexible, but only to a limit. You can bend the to follow a curvature on your boat, bimini, deck etc. They do NOT like bending continuously as happens when they are installed on a flexible background. OK to install them on a curved hard surface, Not ok on a moving flexible background.
You will not notice a difference in 1 year, you will in 4 years, the panels are full of cracks and output is down.
If you install them on the bimini, install them first on a fixed background, plywood, plexi, etc and then fix the background on the bimini.

[Rohan]

Originally Posted by Sdpaddler50

I was also thinking of having my canvas guy sew them in to the Bimini, or another method to get them secure.

I wouldn't do it that way. The only problem with flexible panels is dissipation of heat, so you want as much airflow underneath them as possible. Either sew parallel rows of velcro strips into the bimini and attach them that way, or attach them by the corners using string or wires to fixed points on your bimini (Renogy panels and most others have little openings in the corners for this). If you do it the latter way, make sure it's really tightly secure so they don't flop around in heavy wind.

I had 2x 100w Renogy flexible panels and after a year I liked them so much I got 2x 175 panels instead, all attached by velcro to the bimini. No problems after 2 years.

[Rohan]

Originally Posted by sailormed

If you install them on the bimini, install them first on a fixed background, plywood, plexi, etc and then fix the background on the bimini.

I wouldn't do that. First of all, then you wouldn't get the much needed airflow underneath which is good for the panels, and second of all, if you are attaching them to plywood or plexiglass, then it starts to get much heavier, and you need a frame to hold it up. In that case, you might as well get hard solar panels to begin with.

[Sdpaddler50]

The Bimini we have is relatively flat, with very little curvature.

I appreciate the comments regarding the mounting of the panels to allow for heat dissipation.

The Solbian website (https://solbian.solar/en/) shows various fastening methods for a textile based Bimini like I have.

They also state:
"Velcro flaps all-around the panel, holding the solar laminate from both top and bottom. Perfect for installations on textile structures, highly windproof and aesthetically pleasing. Needs less space than zippers."

I am having trouble visualizing how this arrangement allows for heat dissipation if they are snugly held against the fabric of the Bimini. IE, all of the mounting methods appear to have a tight contact between panel and fabric.

[fxykty]

Originally Posted by Sdpaddler50

The Bimini we have is relatively flat, with very little curvature.



I appreciate the comments regarding the mounting of the panels to allow for heat dissipation.



The Solbian website (https://solbian.solar/en/) shows various fastening methods for a textile based Bimini like I have.



They also state:

"Velcro flaps all-around the panel, holding the solar laminate from both top and bottom. Perfect for installations on textile structures, highly windproof and aesthetically pleasing. Needs less space than zippers."



I am having trouble visualizing how this arrangement allows for heat dissipation if they are snugly held against the fabric of the Bimini. IE, all of the mounting methods appear to have a tight contact between panel and fabric.

Doesn’t the heat just go through the bimini fabric? I don’t imagine there’s much insulation value in Sunbrella or even heavy PVC fabric. Where I have seen heat damage to flexible panels and/or substrate has been when they’re mounted tight against fibreglass.

Surely Solbian isn’t encouraging a solution that would degrade their panels faster?

[hlev00]

Regard heat issues, yes the tests and probably some real world experiences show that heat reduces the output. However, we have had 380W of Solbians for two winters in the Bahamas and four summers in New England velcro'ed directly to our Bimini and are very happy with the output in both environments. When it is hotter the sun is more overhead so maybe that makes up for it a bit. We also have not noticed any significant reduction in output due to age.

Harry

[CarlF]

I mounted my flexible panels on 1/4” twinwall polycarbonate panels. This is used for greenhouse glazing so lasts forever in the sun, It’s great stuff. Very light. Flexible enough to follow a bimini curve but not so flexible that the solar panel can be damaged by bending, The air channels also help with heat disipation. Finally the twinwall can be placed over the bimini stainless bows - something you should never do with a flexible panel.

Available at Home Depot. Cut to size with a strong knife or Dremel. I stuck the solar panels to it with VHB tape and then used velcro to attach to the fabric.

When you remove the panels the twin wall keeps the solar panel from bending too much as you handle it. Just one momentary sharp bend while handling flexible panels can break an internal solder joint.I just toss them on a berth off season. .

When shopping for flexible panels look for a good warranty. Two of my five very expensive Solbian panels failed in a year. They quickly sent replacements. Given the price I guess they can afford it.