Bifacial Solar Panels for yachts

[coopec43]

Bifacial solar panels for yachts?

https://www.youtube.com/watch?v=mzqjCsZKUYQ

A few more links.

https://www.youtube.com/results?sear...nels+on+boat+s

[danstanford]

I found this very interesting as well. I have an electric boat and this model originally had a mainsail with panels sewn into it. Durability made this sail a failure along with the angle of the sun depending on your latitude.

This double sided option could really change the viability of these on boats where real estate for panels is so limited.

[s/v Jedi]

I have 4x Renogy 450W bifacial on the new array: two strings of two series panels in parallel connected to one Victron VE.Can 150/85 so 1,800W total.

We are at 90% irradiance and my peak production is 2,019W and my best 24hr production is 9.03kWh.

So when we correct that for irradiance, we get 2,200W peak and 10kWh production.

Renogy claims up to 30% extra from the back face so that would be 2,340W

[coopec43]

"Because they can better dissipate heat, bifacial panels are also less likely to overheat. Due to this technological advancement, solar panels can continue to operate at better efficiency even when exposed to extended periods of high temperatures".6 Oct 2023

https://solarquarter.com/2023/10/06/...and-materials/

[s/v Jedi]

Originally Posted by coopec43

"Because they can better dissipate heat, bifacial panels are also less likely to overheat. Due to this technological advancement, solar panels can continue to operate at better efficiency even when exposed to extended periods of high temperatures".6 Oct 2023

https://solarquarter.com/2023/10/06/...and-materials/

Yes I believe that. On the other hand they are definitely mechanically weaker. The bifacials are moving a bit when it blows (not the frames, the actual cells) which my monofacials don’t do.

[coopec43]

No way in the world will I install monofacial solar panels

This thread is worth reading as the guys seem to know what they are talking about.

https://www.trawlerforum.com/forums/...nel-69997.html

In Australia our panels are mounted flat on deck or coach house or solar arch. But reading the thread you'd need to tilt them quite significantly (70°?) if you were sailing in higher latitudes.

[rslifkin]

Originally Posted by s/v Jedi

Yes I believe that. On the other hand they are definitely mechanically weaker. The bifacials are moving a bit when it blows (not the frames, the actual cells) which my monofacials don’t do.

I'm not sure that's a mono vs bifacial thing. My monofacial panels flex slightly when it's windy and if the wind hits them just right, they resonate a little and put a noticeable noise through the frames and mounts into the boat. This is with 2 large panels mounted on the cabin top about 2 inches off the deck and angled slightly to each side matching the deck camber.

[coopec43]

"The optimum tilt angle is calculated by adding 15 degrees to your latitude during winter, and subtracting 15 degrees from your latitude during summer. For instance, if your latitude is 34°, the optimum tilt angle for your solar panels during winter will be 34 + 15 = 49°."

https://sinovoltaics.com/learning-ce...t-calculation/

[rslifkin]

Originally Posted by coopec43

"The optimum tilt angle is calculated by adding 15 degrees to your latitude during winter, and subtracting 15 degrees from your latitude during summer. For instance, if your latitude is 34°, the optimum tilt angle for your solar panels during winter will be 34 + 15 = 49°."

https://sinovoltaics.com/learning-ce...t-calculation/

Tilt is tough to do on a boat unless you build a setup that allows you to adjust the panel angle on the fly. It's hard to otherwise get tilt in a useful direction, as the boat doesn't always face the same direction.

[s/v Jedi]

Originally Posted by rslifkin

I'm not sure that's a mono vs bifacial thing. My monofacial panels flex slightly when it's windy and if the wind hits them just right, they resonate a little and put a noticeable noise through the frames and mounts into the boat. This is with 2 large panels mounted on the cabin top about 2 inches off the deck and angled slightly to each side matching the deck camber.

Just reporting my observations

[coopec43]

Originally Posted by rslifkin

Tilt is tough to do on a boat unless you build a setup that allows you to adjust the panel angle on the fly. It's hard to otherwise get tilt in a useful direction, as the boat doesn't always face the same direction.

Agreed. My yacht is a ketch so I will have to hang my panels over the transom maybe like this?





https://atomvoyages.com/the-atom-solar-tracker/

[GordMay]

Originally Posted by coopec43

"The optimum tilt angle is calculated by adding 15 degrees to your latitude during winter, and subtracting 15 degrees from your latitude during summer. For instance, if your latitude is 34°, the optimum tilt angle for your solar panels during winter will be 34 + 15 = 49°."
https://sinovoltaics.com/learning-ce...t-calculation/

Originally Posted by rslifkin

Tilt is tough to do on a boat unless you build a setup that allows you to adjust the panel angle on the fly. It's hard to otherwise get tilt in a useful direction, as the boat doesn't always face the same direction.

FWIW:
Optimum Tilt of Solar Panels ➥ https://www.solarpaneltilt.com/

”... Books and articles on solar energy often give the advice that the tilt should be equal to your latitude, plus 15 degrees in winter, or minus 15 degrees in summer. It turns out that you can do better than this - about 4% better ...”

[coopec43]

Gord
I am so utterly confused.

So far I've found they work well over water as water reflects the sun's rays well on to the back of the bifacial solar panel.

I would use a pole mount so I shouldn't be too worried about installation angle but....

5. Installation Angle
Due to their double sided nature, bifacial solar panels can work at more angles (facing south towards the equator) than monofacial panels. Bifacial panels can even work well at a 90 degree angle. In comparison, monofacial panels need to be installed at between 30 and 45 degrees facing south towards the equator.'

https://www.renogy.com/blog/bifacial...nd-advantages/

AND
Install panels in portrait




Installing bifacial solar panels in portrait, or vertical, does two things.
First, it reduces the amount of the back of the panel that is covered by racking.
Second, it gives snow more room to build up speed as it melts and slides off. Additional momentum helps the snow get past the lower edge of the frame so it can fall to the ground, revealing more of the panel’s surface faster.

https://couillardsolarfoundation.org...-solar-panels/

[GordMay]

Originally Posted by coopec43

Gord
I am so utterly confused.

So far I've found they work well over water as water reflects the sun's rays well on to the back of the bifacial solar panel.

I would use a pole mount so I shouldn't be too worried about installation angle but....

5. Installation Angle
Due to their double sided nature, bifacial solar panels can work at more angles (facing south towards the equator) than monofacial panels. Bifacial panels can even work well at a 90 degree angle. In comparison, monofacial panels need to be installed at between 30 and 45 degrees facing south towards the equator.'

https://www.renogy.com/blog/bifacial...nd-advantages/

AND
Install panels in portrait




Installing bifacial solar panels in portrait, or vertical, does two things.
First, it reduces the amount of the back of the panel that is covered by racking.
Second, it gives snow more room to build up speed as it melts and slides off. Additional momentum helps the snow get past the lower edge of the frame so it can fall to the ground, revealing more of the panel’s surface faster.

https://couillardsolarfoundation.org...-solar-panels/

INDEED! My apologies.

The article, I linked, was discussing MONOfacial solar panels, installed on land.
Merely, an interesting aside, to the conventional [land based] "Latitude ± 15°” advice - not applicable to BIfacial panels, on boats.

[Wandering1]

Originally Posted by coopec43

Gord
I am so utterly confused.

So far I've found they work well over water as water reflects the sun's rays well on to the back of the bifacial solar panel.

I would use a pole mount so I shouldn't be too worried about installation angle but....

5. Installation Angle
Due to their double sided nature, bifacial solar panels can work at more angles (facing south towards the equator) than monofacial panels. Bifacial panels can even work well at a 90 degree angle. In comparison, monofacial panels need to be installed at between 30 and 45 degrees facing south towards the equator.'

https://www.renogy.com/blog/bifacial...nd-advantages/

AND
Install panels in portrait




Installing bifacial solar panels in portrait, or vertical, does two things.
First, it reduces the amount of the back of the panel that is covered by racking.
Second, it gives snow more room to build up speed as it melts and slides off. Additional momentum helps the snow get past the lower edge of the frame so it can fall to the ground, revealing more of the panel’s surface faster.

https://couillardsolarfoundation.org...-solar-panels/

If you are going to pole mount panels, you must be thinking of really small panels? Pole mounts would have to by massive to support a large panel. Why not just mount on the guardrails? This is how we mount 720w of solar on our ketch.
We add an additional 200w of roving panel at anchor. The guardrail mounted panels can be tilted to point at the sun when sailing.
We regularly exceed the manufacturer’s rated peak output for our cheap 180w panels, not bifacial, by up to 15%. Next year, we will likely swap them for some new bifacial panels mounted in the same way, simply because these are getting old. I am not convinced by the hype of bifacial and reading some scholarly articles about performance, it would appear that a gain of about 4-6% is realistic. If I can buy bifacial for the same price then its still worth it