More solar questions

[nautikaljeeper]

Planning a solar project for the boat. I would like to use 2 140W Kyocera panels and 1 90W Solarland (Kyocera KC85T Replacement) to fit on top of bimini. Is the difference in voltage or amps going to create a problem with the MPPT controller? And any suggestions for a highly recommended controller would be appreciated. Another question is would I connect the 3 panels in parallel? I have read several articles on solar topics and have searched this forum to find information to be of great value but I am still feeling a little confused in some areas. I am sure I will have more questions in the near future and any suggestions would be great.

Kyocera 140 Watt 12 Volt Specs:
Ratings:
Voltage 17.7 VDC
Current*7.91 Amps
Power 140W
*
Solarland 90 Wat 12 Volt Spec:
Ratings:
Voltage 17.2 VDC
Curent 5.23 Amps
Power 90W

 

[JohnShannon]

Probably fine, I suspect it would be best to use all the same panels, but it seems for reasons of fit?? you are going to use one different panel.

By connecting in parallel you create one big panel 340W. The MPP controller usually works by subtly varying the load on the panel to find the peak in output power. Dissimilar panels can create local maxima that can trap the controller in a sub optimum point. That said it looks like your panels are similar enough that you should be safe.

What is your alternative?? Just two 140W panels. I suspect even it a subtle mismatch on a 370W system is going to deliver more power than a perfectly operating 280W system.

If MS weighs in ignore everything I said and do what he says/

 

[nautikaljeeper]

Probably fine, I suspect it would be best to use all the same panels, but it seems for reasons of fit?? you are going to use one different panel.

By connecting in parallel you create one big panel 340W. The MPP controller usually works by subtly varying the load on the panel to find the peak in output power. Dissimilar panels can create local maxima that can trap the controller in a sub optimum point. That said it looks like your panels are similar enough that you should be safe.

What is your alternative?? Just two 140W panels. I suspect even it a subtle mismatch on a 370W system is going to deliver more power than a perfectly operating 280W system.

If MS weighs in ignore everything I said and do what he says/

Yes it is about fit. Trying to use the rest of available space. I could always resort to two 140 panels but I am trying to get closer to my amp/hr useage. I could use two larger panels but I am trying to stay inside the bimini footprint for a nice balance of "Form and Function". I have read about for panels connected in parallel, current is additive while voltage is the same. If among the panels connected in parallel there is a panel with rated voltage lower than the others, it will drag down the voltage on all the remaining panels. So my concerns are that the minor amount of voltage difference would cause a problem. Most important is what effect it would have on the controller.

 

[JohnShannon]

Basically the voltage is the same for both those panels. The all panels are more or less the same. They are comprised of a series string of cells. your panels look like they have peak power at 17V sounds like 36 cells in series. The 90W panel has smaller cells.

The other potential difference might be polycrystaline vs. monocystaline cells. These exhibit different behavior specially at low light.


But again your maybe slightly wacky 370W array should for sure outperform a "perfect" 280W system.

Looking at the spec the most it can be "dragged down" would be to 17.2V from 17.7

So that is a loss of 0.5V on 14A of output about 7W and you pick up the 90W of output from the panel that is doing the "dragging down". In fact the effect should be less than that

 

[nautikaljeeper]

As far as what I am reading they are both polycrystaline cells. Thank you for your help.

 

[Johnb]

I am curious, which models did you choose?

Thanks

 

[nautikaljeeper]

I haven't chose any yet. Just planning. I would like to go with what i posted.

 

[John Nantz]

Controller max amperage

The controller will have a maximum amperage and the sum of the panel output shouldn’t exceed that. The panels are rated at a certain temperature and their output will be different at other temperatures so the output may actually be higher than their rating.

Typically, with anything electronic, there is a wear-and-tear factor to consider when something is operated at high output. Over time, capacitors and diodes wear out and this will obviously cause the circuit to change so overdesigning parts of the system to avoid heat, which is the usual killer, will help the system to last longer. Just something to consider.

Edit: going solar is an excellent idea.

 

[Johnb]

I haven't chose any yet. Just planning. I would like to go with what i posted.

Just curious because whilst the Kyocera references resistance to salt spray the solarland does not - that I could see.

 

[Bob 04 H260]

We put a Kyocera 325W panel over our Bimini on our H356. I found the large panel easy to mount behind the arch with a simple home built frame.

The higher voltage and one panel I think is more efficient, and well priced, https://www.emarineinc.com/Kyocera-325-Watt-Solar-Panel-Fixed-Frame-KD325GX-LFB

We used a Rogue controller.

With LED lights this one panel can supply all our needs if we get 3 out of 4 days sunny. Our energy budget is about 100Ahrs per day to run our fridge, freezer and lights. We are usually back up to 100% by early afternoon and use the "extra" power to charge laptops etc.

I have detailed photographs of my panel install in an album "Windsong II" on my profile page here on Hunterowners.

Good luck, Bob

 

[Rick]

If it was me, I would spend the money on an asymmetrical spinnaker! Capt Slocum didnt have no solar panels!

LOL... see ya round the docks slip mate

 

[Maine Sail]

Planning a solar project for the boat. I would like to use 2 140W Kyocera panels and 1 90W Solarland (Kyocera KC85T Replacement) to fit on top of bimini. Is the difference in voltage or amps going to create a problem with the MPPT controller? And any suggestions for a highly recommended controller would be appreciated. Another question is would I connect the 3 panels in parallel? I have read several articles on solar topics and have searched this forum to find information to be of great value but I am still feeling a little confused in some areas. I am sure I will have more questions in the near future and any suggestions would be great.

Kyocera 140 Watt 12 Volt Specs:
Ratings:
Voltage 17.7 VDC
Current*7.91 Amps
Power 140W
*
Solarland 90 Wat 12 Volt Spec:
Ratings:
Voltage 17.2 VDC
Curent 5.23 Amps
Power 90W

Your MPPT will simply use the sum powerpoint of all the panels in parallel. With panels that close in voltage (hopefully they perform similarly in varying temps) you're losing fairly little vs. what you gain by adding the 90W. You could also go with two slightly larger panels that are identical as another option. The Kyocera KD255's may even fit....??

 

[nautikaljeeper]

We put a Kyocera 325W panel over our Bimini on our H356. I found the large panel easy to mount behind the arch with a simple home built frame.

The higher voltage and one panel I think is more efficient, and well priced, https://www.emarineinc.com/Kyocera-325-Watt-Solar-Panel-Fixed-Frame-KD325GX-LFB

We used a Rouge controller.

With LED lights this one panel can supply all our needs if we get 3 out of 4 days sunny. Our energy budget is about 100Ahrs per day to run our fridge, freezer and lights. We are usually back up to 100% by early afternoon and use the "extra" power to charge laptops etc.

I have detailed photographs of my panel install in an album "Windsong II" on my profile page here on Hunterowners.

Good luck, Bob

Thanks for the response Bob. That gives me a bit more insight as how the panel handles your power needs. The Rouge controller you have is my first choice but as I have read it has been discontinued.

 

[nautikaljeeper]

Your MPPT will simply use the sum powerpoint of all the panels in parallel. With panels that close in voltage (hopefully they perform similarly in varying temps) you're losing fairly little vs. what you gain by adding the 90W. You could also go with two slightly larger panels that are identical as another option. The Kyocera KD255's may even fit....??

Thank you Maine Sail for your imput. I was hoping the difference in voltage wouldn't be a concern. The KD225's were being considered but the reason with for my current choice of arrangement is to stay inside the footprint of the bimini and keep the over head view. Since the Rogue MPT-3048 has been discontinued what would be your first choice for this array?

 

[Bob 04 H260]

You are welcome.
I can understand wanting to see the mainsail. My plan is to move my window in front of the arch, I think it will provide a better view and be easier on my neck !
Bob

 

[nautikaljeeper]

If it was me, I would spend the money on an asymmetrical spinnaker! Capt Slocum didnt have no solar panels!

LOL... see ya round the docks slip mate

Yes but the other half would just as soon start the motor instead of raise the sail. And I am sure she would enjoy that ice cream at anchor more than the spinnaker.:dance:

 

[PeterBreit]

Bob, very nice installation pictures in your album. I have a 140W panel, (bought also at emarine) installed on my davits. Do you keep your panel always turned on ? even when pugged in to shore power or running the engine ? It seems mine confuses the Link 100 when I do this, it gives me error codes.
Cheers
Peter

"BELVEDERE"
Beneteau Oceanis 461
Kent Narrows, MD

 

[Stu Jackson]

Smitty has a great writeup of his solar system design

https://svsmitty.wordpress.com/category/upgrades-repairs/electrical-system/page/2/

 

[Bob 04 H260]

Bob, very nice installation pictures in your album. I have a 140W panel, (bought also at emarine) installed on my davits. Do you keep your panel always turned on ? even when pugged in to shore power or running the engine ? It seems mine confuses the Link 100 when I do this, it gives me error codes.
Cheers
Peter

"BELVEDERE"
Beneteau Oceanis 461
Kent Narrows, MD

Peter, yes I leave it on all the time, so far no confusion. I don't have a Link but use a Victron battery monitor. I could see how the charger and solar controller could confuse each other but so far as I can tell they work together ok. Now I often leave the boat unplugged in a slip unless we need AC. That can save $20 a day in the Bahamas and saves the zincs !
Bob