Which Solar Panels for this giant hardtop?

[Scorpius]

Originally Posted by Pelagic

I think the biggest concern in yacht instalations is the potenial racking moment and stress when the boat is in rough weather

That is far more severe than a land installation and while the wind loading is the same, the G forces are not

So I chose to make heavy alloy racks that the Sunpower panels fitted into quite tight to stiffen up the panel's own frame.
2 panels per side
Used sealant to bed them down and sealed top to prevent any salt water getting trapped inside.

Salt spray does not seemed to have been an issue after about 6 years on.

By the way, what is the expected electrical generating lifespan of solar panels ?

Attachment 232670Attachment 232671Attachment 232672

I just had an aluminum frame built of 2" T-bar (inverted) and angle to fit snugly around the six solar panels, then put the whole thing up there as a bimini. No fabric to run screws or wires through and it's strong as heck. Also serves to collect water with a couple of pipe fittings at the after end. It also supports a swing-out davit / crane to lift an outboard off the dinghy or whatever.

I'm very, very happy with it.

[noelex 77]

Originally Posted by jmschmidt

Better check into this for any panel that will go into a boat.

In practice, rigid solar panels seem to be one of the most reliable products you can install on a boat. No moving parts with few discrete electronic components combined with durable glass and aluminium parts is probably the fundamental reason for this reliability, but whatever the reason they are typically durable on boat despite generally being constructed to survive on the roof of building rather than a marine environment.

Excluding mechanical damage from collisions, a failure to secure to the panels properly, and the occasional lightning strike, defects in the panels themselves seem very rare.

More expensive panels have a higher quality of construction and quality control. These differences can be easily seen, but even relatively cheap rigid panels seem to have an acceptable life that is generally better than most other dedicated marine equipment.

Unfortunately, the same has not been true for flexible panels, although the life of modern flexible panels will not be known for some time. There are some advances in the construction of these panels in recent years that suggests the life may improve.

[Quadrille in JB]

PM me for SunPower availability

[Simi 60]

We put 9 x 250w Jinko panels on our roof
Tier 1 company, great quality, got them second hand on Gumtree for about $80 each delivered to the boat when on the hard.
Still had 9 1/2 years of the 10 year warranty on them.
https://www.gumtree.com.au/s-jinko+solar/k0

To mount them I got hollow recycled plastic garden sleeper, cut into blocks, bolted panel to them and then sikaflex to the roof.
No fasteners or holes.

They have seen multiple storms over the past 4 1/2 years, one with 80+ knot gusts, no issues.

Added bonus was that with a near 2 inch space under the panels for airflow, the cabin is so much cooler as it never sees any direct sun or heat.

[rslifkin]

Originally Posted by Simi 60

We put 9 x 250w Jinko panels on our roof
Tier 1 company, great quality, got them second hand on Gumtree for about $80 each delivered to the boat when on the hard.
Still had 9 1/2 years of the 10 year warranty on them.

To mount them I got hollow recycled plastic garden sleeper, cut into blocks, bolted panel to them and then sikaflex to the roof.
No fasteners or holes.

They have seen multiple storms over the past 4 1/2 years, one with 80+ knot gusts, no issues.

That resembles the mounting I'm planning for my panels. My plan is to bolt pieces of aluminum angle to the panels and adhere another set to the deck. Then the 2 pieces of angle bolt together to hold the panels, making it possible to remove them if I someday feel like cleaning under them.

[Seafarer7]

Originally Posted by JasonS

We put 3 LG 375 watt panels on our Manta 40 hardtop a year ago. Extremely happy with them and no issues noted. We run them in serial through a 150/100 Victron. We’ve seen voltage out of the panels as high as approx 123 volts, amps pushing over 80, and watts over 1000 (1125 would be max rated). Most of the time, we don’t even need what we have but nice to have on cloudy days. We’ve all but eliminated our need for generator except to run AC at anchor and heat hot water, although I’m going to look into a 12 volt heating element for our water heater. Good luck with your install. Here’s picture from last 4 days of solar generation while at anchor in the Florida Keys.

JasonS: very impressive - thanks for sharing. From your screenshot I dare say (guess) you may be significantly in need of more battery storage. You’ve got a powerful (>1kw) solar array, and are clearly hitting your absorption charge phase daily (>14.4v), and yet you appear to be draining your battery bank significantly (below 12v, greater than 50% depth of discharge/DOD) daily. So while you have abundant energy supply (to the point of discarding excess daily), your batteries appear to be dipping too low each day - which is not good for the batteries (life measured in # of deep cycles and that # is sensitive to the DOD). I would guess you have a lead acid type (incl AGM), not lithium, from those voltages, so they probably have 300-500 cycles in them at those DOD levels).

I would recommend doubling or tripling your battery bank size. Your battery depth of discharge would drop to 20% or so, # cycles would disproportionately increase, and your batteries would live much longer (non linear benefits that greatly outweigh the cost).

[SunPoweredYachts]

SunPower panels are available! We're slowly getting the word out there but as a SunPower Authorized Dealer we can now offer the SunPower fixed frame DC panels to the marine market. There's a 350W, 370W & 410W panel.

[rslifkin]

Originally Posted by SunPoweredYachts

SunPower panels are available! We're slowly getting the word out there but as a SunPower Authorized Dealer we can now offer the SunPower fixed frame DC panels to the marine market. There's a 350W, 370W & 410W panel.

Any idea when you might have pricing listed for the 410W panels? They're a decent bit shorter in length than the other 400+ watt panels I've been looking at, meaning I'd have space to add a pair of 100W panels next to them if desired. As long as they're not crazy expensive like the fairly compact 380W LG panels, I'm likely interested in a pair of them.

[SunPoweredYachts]

The 410W panels are 40" (W) x 72" (L). We won't be publishing prices on our site as we have to discuss each project, send us an email info@sunpoweredyachts.com

[JasonS]

Seafarer 7: A reasonable observation based on my post, but...
we make water for French pressed coffee every morning with an electric hot water maker. It takes about 5+ minutes and draws 140amps. During this time the batteries are drawn for short periods to the 11.4-11.7amps you are seeing on the Victron display I posted. As solar charging has already begun, the Victron is showing the low voltage number. We have a Lifeline AGM Battery bank of 6 6v batteries. It gives us 660ah bank. We typically wake up with Xantrex battery gauge showing -90 to -120ah, and battery voltage usually 12.5 volts with 12.3 being the lowest we’ve seen in last 10 months of active cruising on the hook.Thanks for noticing and commenting!!!

[noelex 77]

Originally Posted by Seafarer7

You’ve got a powerful (>1kw) solar array, and are clearly hitting your absorption charge phase daily (>14.4v), and yet you appear to be draining your battery bank significantly (below 12v, greater than 50% depth of discharge/DOD) daily.

The voltages shown are a little low, but I think you are confusing minimium voltage readings recorded under load with the resting bank voltage readings. These two types of measurement are very different.

[Seafarer7]

Originally Posted by JasonS

Seafarer 7: A reasonable observation based on my post, but...
we make water for French pressed coffee every morning with an electric hot water maker. It takes about 5+ minutes and draws 140amps. During this time the batteries are drawn for short periods to the 11.4-11.7amps you are seeing on the Victron display I posted. As solar charging has already begun, the Victron is showing the low voltage number. We have a Lifeline AGM Battery bank of 6 6v batteries. It gives us 660ah bank. We typically wake up with Xantrex battery gauge showing -90 to -120ah, and battery voltage usually 12.5 volts with 12.3 being the lowest we’ve seen in last 10 months of active cruising on the hook.Thanks for noticing and commenting!!!

Ah! That makes sense. Thanks!

[JasonS]

Noelex - getting a true ‘resting voltage’ while living on your boat at anchor is not practical. But we have a pretty good idea of battery health and daily charging. Sitting here at 11:30pm, we are down roughly 50Ah and voltage is 12.7. Both fridge and freezer running, anchor light, a couple cabin lights on, and 12 volt charging of phones/iPad. Using a bit over 7 amps. By sunup we will likely be down 100Ah or so and will be at 12.5 volts. Freezer/fridge will likely be off (thermostats set to 9 F and 37 F which gives us a range in the boxes of 0-20 F and 33-40 F as mid/bottoms coldest and tops warmest). So nice to have ice cream, but I digress ��.

So as close as we can measure ‘resting’, we have very minimal draw at sunrise, usually in the 2-2.5A range, and will typically be at 12.4-12.5. And then the morning Krups electric water kettle (rated at 1500 watts) is turned on and pulls roughly 140amps, drawing the voltage down to 11.4 to 11.7 while it is running. When the kettle is turned off the voltage quickly returns to 12.4+. Solar charging begins soon after sunrise in our system as three panels are wired serially. Since Victron is already in bulk and started day, it’s picking up the low voltage from the few minutes of high draw. We love not having to heat water by propane and heat up the entire boat. We use an Instapot and have a bread maker as well. Typically make bread during the day when we have excess of solar. Now if we can only find a way to sell our excess to other boaters running genny’s in the Anchorage at midnight ��

[noelex 77]

Originally Posted by JasonS

Noelex - getting a true ‘resting voltage’ while living on your boat at anchor is not practical.

I agree it is not feasible to measure resting voltage for cruising yachts most of the time.

A comparison of voltage readings under similar conditions (primarily focusing on the discharge/charge current and history) can give some useful information, but it is wrong to apply resting voltage tables to batteries under load.

Unfortunately, people often incorrectly apply these tables to batteries under load and draw false conclusions about the batteries SOC.

[Lost Horizons]

Originally Posted by SunPoweredYachts

The 410W panels are 40" (W) x 72" (L). We won't be publishing prices on our site as we have to discuss each project, send us an email info@sunpoweredyachts.com

Is there a particular reason, other than a desire to sell a “project,” why large solar panels are not sold to end consumers? The highest capacity panels available on Amazon are 200 W, and there are not many choices there in this size, the vast majority is 100 W. I suppose, shipping can be a problem, but then local marine stores like Fisheries do not carry them either. I would like to get a couple or maybe initially just one 400 W panel, but it looks like it is not going to happen. Will probably go with three 200 W panels from Amazon, which I hate to do, but there seems to be no alternative. Am I missing something?