Solar wiring plan feedback

[tarch]

Good evening everyone.

I am hoping to tackle a solar panel installation on a new to me boat and am out of my depth. However, I am willing to learn, hopefully not from my mistakes.
I have been reading various articles and watching youtube videos and came up with following setup. I am hoping to get some advise, guidance etc.


Sources:
Solar panels 500w x2
Hyperion 400W Front + 100W Rear Bi-facial Solar Panels

Hyperion 400W Bifacial Solar Panel (Black) | Up to 500W with Bifacial Gain

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL

signaturesolar.com

WEN Generator

WEN Super Quiet 3600/2900-Watt Lightweight RV-Ready Portable Inverter Generator with Fuel Shut Off and CO Watchdog 56360iX - The Home Depot

Produce up to 3600 surge watts and 2900 rated watts of power. The WEN Watchdog CO Shutdown Sensor helps protect both you and your family by automatically turning off the generator if dangerous levels of carbon monoxide are detected. Our 149cc engine operates at a modest 65 decibels at quarter...

www.homedepot.com

Storage:
300-400Ah LiFePO4 battery/batteries such as

https://www.amazon.com/dp/B07RP5B5P7/?coliid=I25XLY9I5F2AN4&colid=27HW7BL8EK7KD&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

Control:
Victron SmartSolar MPPT 100/15 Solar Charge Controller 100V 15A with Bluetooth

https://www.amazon.com/dp/B075NQH3QW/?coliid=I2R33D5KXE9LBL&colid=27HW7BL8EK7KD&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

Renogy 500A Battery Monitor with Shunt

https://www.amazon.com/dp/B07RP5B5P7/?coliid=I25XLY9I5F2AN4&colid=27HW7BL8EK7KD&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

Loads:
Koolatron Super Kool 45 Portable Fridge OR BougeRV 12 Volt Refrigerator

https://www.amazon.com/dp/B07ZL49RNT/?coliid=IGU94EOWWS1WH&colid=27HW7BL8EK7KD&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

https://www.amazon.com/dp/B08G1BBBQW/?coliid=I1VIYYE20H6C06&colid=27HW7BL8EK7KD&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

LG AC LW5016 5,000 BTU

5,000 BTU Window Air Conditioner - LW5016 | LG USA

Discover the 5,000 BTU Window Air Conditioner that features 5,000 BTU and 150 Sq. Ft of Estimated Cooling Area. Shop LW5016 from LG USA.

www.lg.com

This is for a small catamaran. I am hoping to run a 5000BTU AC, in Florida, expecting it to run a few hours at most during the night, more during the day.
The AC is like LW5016 - I will need to modify the cooling side to run on sea water - like a pipe in pipe condenser. It claims to suck up 440w but I am sure it will pull quite a bit more at the start. I am thinking about soft start unit to ease the pain.

Apart from AC, I wish to run a small fridge/freezer, some lights, navigation equipment that is of low demand and a couple of low power laptops, occasionally water maker. I don't have the type/demand of the water maker yet.

I am going to include a toon style layout I made for people with knowledge and experience to guide.

Also, the Victron MPPT charger says 100v 15A, am I right in thinking that means it can tolerate up to 100v and can accept up to 1500W of input power from solar?


My understanding is that with the sun in FL, I can get approx 40AH from a 100W solar panel. Thus, a 1000W panel in ideal world should give me enough to fill 400AH daily. This translates to 400AH at 12 v = 5000WH

An AC that draws 440W and run for 5 hrs a day will suck up 440w x 5 = 2200 WH.
A fridge that is claiming to draw 50W and run continuously should eat up 1200 WH
Two laptops together at 130W, used for around 8 hrs, leading to approx 1000WH
All the lamps are LED and in theory take very little.
I don't have a radar to eat up juice
I do have a chart plotter but don't know the demand of it.

This should leave me enough to use the laptops and some lights and fans.

This is separate from a starter batter that gets charged with a small solar panel/charge controller and the alternator. I would like to separate the two systems completely just so that I can get my head around the wiring.

Does it look sane/feasible?
Or did I err?

Thanks all in advance

 

[DIYrich]

Missing inverter for AC. Idea: get a 12v RV AC, and run everything off 12v.

Don't count on the backside of bifacial. Consider it a bonus.

 

[tarch]

Missing inverter for AC. Idea: get a 12v RV AC, and run everything off 12v.

Don't count on the backside of bifacial. Consider it a bonus.

Hi Rich

The tan colored box left of the AC panel is the inverter in the crude schematic. I looked up the 12v AC systems for RV - I can't seem to find any that are using as low as 400-500W. Most seem to eat up 600-1000W. I wonder if economy of scale makes the window models the more efficient ones. Do you have any recommendations for the 12v AC?

I know I need to calculate loads down each leg from AC and DC distribution panels and size the wires accordingly still.

Does my overall plan and expectation seem to be in the ball park or any rookie mistakes anyone can see?

Thanks

 

[robbob2112]

Hi Rich

The tan colored box left of the AC panel is the inverter in the crude schematic. I looked up the 12v AC systems for RV - I can't seem to find any that are using as low as 400-500W. Most seem to eat up 600-1000W. I wonder if economy of scale makes the window models the more efficient ones. Do you have any recommendations for the 12v AC?

I know I need to calculate loads down each leg from AC and DC distribution panels and size the wires accordingly still.

Does my overall plan and expectation seem to be in the ball park or any rookie mistakes anyone can see?

Thanks

The links for your battery storage in the first post takes me to the battery monitor verse actual battery. Hopefully we can steer you away from Renology. They have a pretty bad reputation especially when something goes wrong.

This inverter is the one I have, it has more power than what you are looking for, but that isn't a bad thing. The standby draw is lower than most inverters and it has an eco mode so it turns all but off unless there is something turned on and demanding power.

Victron 12V Phoenix 1.2kVA 120V Inverter VE.Direct | Current Connected

Stay connected and power up confidently with the Victron Phoenix Inverter. Advanced features for a customizable and efficient power solution.

www.currentconnected.com

Also a fridge may say 50w but they cycle on and off all the time. Usually they draw triple for a bit, then nothing and more. If they have an actual compressor to start you would be looking at 5x the rated wattage for a few seconds when it cycles on. The inverter I linked handles my full size fridge with no trouble at all.

The AC that draws 550watts may be your real issue. Unless it has a soft start it will probably draw 2500w for a second or so when starting. It might work on the Phoenix and it might need a 2000w low frequency model like this or even the 3000w version.

https://www.amazon.com/Victron-MultiPlus-Compact-Inverter-Charger/dp/B01AD2MJSK?th=1

Look on the unit or in the paperwork and most AC units list the starting current.


The differnence between the LF and HF inverters is that the LF use a large chunk of iron and wire wrapped around it and can tollerate the starting surge for 30 second to several minute. The HF are light weight and can only do startup surge for a few seconds or less. The HF units are cheap compared to the LF units.

Most LF these days are actually hybrid to an extent, HF from the battery into the first stage and LF in the second stage. Works out to the same result as the older pure LF units.

At 12v that sort of power draw can be a lot of amps for a short amount of time, but you have to wire and fuse things accordingly. Consider switching to 24v or 48v. Then get a buck converter to step back to 12v for your DC loads. This cuts the wire sizes by 1/2 or 3/4 and the current by the same. Smaller fuses. 48v inverters are typically a bit cheaper than 12v or 24v. With the savings you can maybe do a server rack battery or a single 48v battery. Don't try to build one from 12v batteries unless you must.

Add a tub of 'no-ox-id special' to your shopping list, this is for all the contact points to prevent corrosion.

Edit your drawing to include fuses and wire sizes.

Your plan and basic design is sound, as with most thing the devil is in the details.

And don't buy anything until you have hammered out the whole design.

 

[tarch]

Sorry about the battery link. Here is the right one.

https://www.amazon.com/dp/B0CSFSDHPM/?coliid=IP0LWG2S9QMHD&colid=27HW7BL8EK7KD&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

Looking at the massive toroid in the Victron you have, it seems to be LF.
I can perhaps split the 120AC supply to two separate sections, one with LF inverter to run the air con and one for the loads with low in rush such as laptops etc.

I can also go with DC-DC converters to provide 19v for laptops and get a 12v fridge. Then the only main need for 120vac will be aircon.

Thanks for the advise about no-ox-id

The Victron MPPT charger says 100v 15A, am I right in thinking that means it can tolerate up to 100v and can accept up to 1500W of input power from solar? I can put 2 large panels, each at 12v - so I can run them in series but the downside is if one is in shade since it is a sailboat after all, from my reading the efficiency drops. That is the reason I put them in parallel in the schematic.

Yes, I am going to have the wiring/details planned out before ordering anything.
Thanks Robbob

 

[robbob2112]

To victron 100/15 means max 100v and it will put out a max of 15 amps. Basically it means it will use the voltage and current coming in from the solar panels and convert it to the correct voltage for the batteries to charge.

Make certain not to exceed the voltage input even by a bit or it will burn out. Solar panels are like a full barrel of water you tap, they only give you the amouht you ask for. So you don't have to worry about overdoing the Isc (current short circuit). Voltage increases in cooler temperatures, but that probably isn't much problem for you.

That is just about the same battery I have as part of my UPS for my server. If you intend to run the AC very long you will need more than one of them. Figure 550watts x number of hours to run and not drop below 20% for maximum battery life. So figure 4 hours each with no other drain give or take a bit. Hotter day more compressor cycling more usage, cooler day less cycling.

Correct, the phoenix is a LF inverter capable of 3000w for almost 30 seconds so it might work for you if there is nothing else on when the AC is cycling.

It is possible to split out the AC but only with something that does 240 split phase or separate electrical panels that aren't connected together at any point. I was originally thinking might do it with a 240 panel and just have the left side be on the LF and the right side be on the HF, but I am pretty sure it would burn up one or both inverters. Besides the extra panel costs and other precautions would add $$ and still not meet the ABYA regulations.

Depends on the panel but just about all of them loose all output when shaded. So it might be better to look for smaller panels you can string in parallel so if one drops out the rest still work. Use the criteria of watts per square meter/efficiency verse pure raw wattage. This method might not look as pretty as a couple of big panels but should conform to the hull better.

Running things off battery voltage directly cuts out a lot of the conversion inefficiency.

There are DC split units, not sure how they would fit but might be worth looking into.

Once you figure that out and the draw you can figure out how many batteries you need. From there you will be able to figure fuses and wires.

 

[Bop]

The Victron MPPT charger says 100v 15A, am I right in thinking that means it can tolerate up to 100v and can accept up to 1500W of input power from solar? I can put 2 large panels, each at 12v - so I can run them in series but the downside is if one is in shade since it is a sailboat after all, from my reading the efficiency drops. That is the reason I put them in parallel in the schematic.

It means the combined Voc ratings of the panels can't exceed 100v (and personally, I have seen my own panels here in Australia go 15% past their marked Voc in the wrong weather conditions- I never go past 80% of the PVmax rating of the charge controller- it WILL dies sooner or later through a brief voltage excursion...)

The 15A is what its maximum OUTPUT is (not what the PV input current is) so on a 12v nominal battery bank, the limit for a Victron 100/15 is only 220w, and only 440w in total on a 24v nominal battery system so your controller is totally inadequate for TWO 400w panels (indeed it would struggle with only ONE 400W bifacial and would start clipping in good generating conditions with 400w coming in the front and 100w coming in the back even on a 24v battery bank...)


(from section nine at Victron 100/15 specs)- your '1500w' is WAAAY off the limits of what they can handle... you are confusing the INPUT limit with the OUTPUT limit... a common mistake for beginners)

You have to remember the panels output ratings are ONLY at STC (standard test conditions) and when they aren't at those specific conditions (1000w/m^2 solar insolation, panel temp of 25C and atmospheric mass of 1.5 (the height from sealevel to the top of the earths atmosphere is 1AM) then its output can be lower (which is usual) or higher... (If the light levels go up, so does the voltage, if the temperature goes up, the voltage and power go DOWN, and if your boat is sailing on a mountaintop (what is it, the Ark lol) then the AM goes down and the power and voltage go UP...)

(see the STC ratings?)

Series arrays will generate more total daily power than parallel arrays- your MPPT controller may not even get into MPPT mode at all on a set of '12v' panels (thats salestalk, and tells us nothing) as it requires usually about 5v above the battery voltage before it even starts up (most will run in PWM mode before this- with the accompanying about 30% loss in generation) and many '12v' panels with a VOC of 18-20v may not get high enough 'loaded' (VMP rating of 16v-18v) to get 5v above the battery voltage until well into the day, or possibly ever!!!

If you are using the 400w Hyperions then the Voc is 37.07v, two in series will give you 72.14v Voc- which is actually almost perfectly matched to a 20% derated 100V charge controller (0.8 x 100v =80v)- these in nobodies right mind would be considered '12v panels' with a Vmp of 31v!!!


Shading a panel in series array reduces the array output yes, but so does shading a panel in a parallel array, and the added benefits of the series array (earlier start and finish times, both for charging and MPPT operation, plus better poor weather (overcast) performance by far makes up for it... but forget the Victron 100/15- you are looking at a 100v 80a minimum controller for a 12v battery bank, or a 100v 40a for a 24v battery bank- and both of those is running right at their upper limits- a 100v 100a on a 12v battery bank or a 100v 60A on a 24v would be less stressed in good conditions and a better choice... (with a potential 1000w of input coming in with two of those Hyperion 400w bifacials , your controller would be putting out 78.7a into a 12v battery bank and 39.3a into a 24v battery bank... the Victron 100/15 is seriously outclassed by these panels...

Bifacial panels require a good light source for the back (don't laugh- I have seen bifacial panels mounted FLAT and hard up against the roof of an RV- um how does light get to the back side of it???)- If you are planning a stern mounted array on the stern arch (especially if it 'hangs out over the water', then bifacials make a LOT of sense (reflected light from the water can get a major improvement in performance- indeed in some cases it may even pay to mount the panels upside down with the 100w side facing up and the 400w facing down!!!) but putting them on the cabin roof- forget the bifacials altogether...

 

[tarch]

To victron 100/15 means max 100v and it will put out a max of 15 amps. Basically it means it will use the voltage and current coming in from the solar panels and convert it to the correct voltage for the batteries to charge.

Got it. So, 100 is the max input voltage tolerated and the 15 is the output amps - when multiplied by output voltage gives output capacity.

Make certain not to exceed the voltage input even by a bit or it will burn out. Solar panels are like a full barrel of water you tap, they only give you the amouht you ask for. So you don't have to worry about overdoing the Isc (current short circuit). Voltage increases in cooler temperatures, but that probably isn't much problem for you.

That is just about the same battery I have as part of my UPS for my server. If you intend to run the AC very long you will need more than one of them. Figure 550watts x number of hours to run and not drop below 20% for maximum battery life. So figure 4 hours each with no other drain give or take a bit. Hotter day more compressor cycling more usage, cooler day less cycling.

I can then get a 200Ah-300Ah 24v battery

Correct, the phoenix is a LF inverter capable of 3000w for almost 30 seconds so it might work for you if there is nothing else on when the AC is cycling.

It is possible to split out the AC but only with something that does 240 split phase or separate electrical panels that aren't connected together at any point. I was originally thinking might do it with a 240 panel and just have the left side be on the LF and the right side be on the HF, but I am pretty sure it would burn up one or both inverters. Besides the extra panel costs and other precautions would add $$ and still not meet the ABYA regulations.

I don't have enough knowledge at present to try something like the split phase. I was thinking more in terms of 2 2KW inverters running to two AC outputs, one pretty much only running the AC and one for everything else.

Depends on the panel but just about all of them loose all output when shaded. So it might be better to look for smaller panels you can string in parallel so if one drops out the rest still work. Use the criteria of watts per square meter/efficiency verse pure raw wattage. This method might not look as pretty as a couple of big panels but should conform to the hull better.

This might be easier. Large, high wattage panels available on market place cheaply are inviting but smaller panels might confirm better too.

Running things off battery voltage directly cuts out a lot of the conversion inefficiency.

There are DC split units, not sure how they would fit but might be worth looking into.

Once you figure that out and the draw you can figure out how many batteries you need. From there you will be able to figure fuses and wires.

I tried to find the DC split units and the efficiency doesn't seem to be on par with the humble domestic mini splits or window units, perhaps from the economy of scale.

Thanks

 

[robbob2112]

I'm out and about at the grocery. I'll answer more when home. I forgot you are in Australia. Two of the 2k victron units tied together so they sync the phase and just output your standard 240v power would be the best option.

Calling @sunshine_eggo - our local Victron expert. He is a wizard at all things victron and can work our this detail better than I.

On panels @Bop has some points. A bigger or multiple MPPT would be a good idea. I like the idea of redundancy on a boat so if something fails you still have power.

I do disagree with him on hanging the panels over the stern. In heavy weather you would likely loose them. So I would stick to the most efficient ones you can fit in your space. Maybe a port and starboard set? Or fore and aft?

And for heavy weather mounting them close to the roof makes more sense so skip the bifocal ones. The Eggo will probably also have an opinion.

I think 24v makes a lot of sense, multiple with bus bars and fuses.

The ABYA is a yank thing, but the rules are for boats and yachts and I think the safety items are all good to implement since you don't want a fire or failure at sea. My wife is from Adelaide so I kinda understand the slang now.

 

[Bop]

Its actually quite common for boats to have them mounted on the stern arch if present (it obviously has to be designed to handle the loads of course) and is commonly seen here in Australia...
I probably wouldn't recommend them on a deep sea vessel, but for those who don't venture out in cyclones, they seem quite up to the job (and would certainly be the ideal mount for bifacials)

This kind of thing is quite common where I used to live (up Mackay, near the barrier reef) and the ones in the marina all survived intact through a cyclone that took out many houses roofs even, so I suspect the likelihood of them actually being damaged is quite low assuming the arch is of adequate construction...

Flat conventional panels on the roof of the cabin work also- in fact why not have both??? the more panels you can find a spot for (even if they aren't optimal) the more power you can generate- and wanting to run A/C etc- is going to need every watt he can squeeze out of the system....

 

[robbob2112]

Its actually quite common for boats to have them mounted on the stern arch if present (it obviously has to be designed to handle the loads of course) and is commonly seen here in Australia...
I probably wouldn't recommend them on a deep sea vessel, but for those who don't venture out in cyclones, they seem quite up to the job (and would certainly be the ideal mount for bifacials)

This kind of thing is quite common where I used to live (up Mackay, near the barrier reef) and the ones in the marina all survived intact through a cyclone that took out many houses roofs even, so I suspect the likelihood of them actually being damaged is quite low assuming the arch is of adequate construction...
View attachment 214470View attachment 214472
Flat conventional panels on the roof of the cabin work also- in fact why not have both??? the more panels you can find a spot for (even if they aren't optimal) the more power you can generate- and wanting to run A/C etc- is going to need every watt he can squeeze out of the system....

OK, now I see what you mean, it wasn't what I thought.... I can agree with this.

 

[tarch]

I'm out and about at the grocery. I'll answer more when home. I forgot you are in Australia. Two of the 2k victron units tied together so they sync the phase and just output your standard 240v power would be the best option.

Sorry Robbob. I am in US - Florida.

Calling @sunshine_eggo - our local Victron expert. He is a wizard at all things victron and can work our this detail better than I.

On panels @Bop has some points. A bigger or multiple MPPT would be a good idea. I like the idea of redundancy on a boat so if something fails you still have power.

I was thinking of separating partly to get my head around and partly for redundancy.

I do disagree with him on hanging the panels over the stern. In heavy weather you would likely loose them. So I would stick to the most efficient ones you can fit in your space. Maybe a port and starboard set? Or fore and aft?

And for heavy weather mounting them close to the roof makes more sense so skip the bifocal ones. The Eggo will probably also have an opinion.

I am planning to mount them close to the deck with perhaps a centimeter of gap for some cooling.
I was hoping to mount one over the dinghy davits since I have seen it being done a lot. However, I haven't seen one while at sea and wouldn't know how it handles in heavy weather.

I think 24v makes a lot of sense, multiple with bus bars and fuses.

The ABYA is a yank thing, but the rules are for boats and yachts and I think the safety items are all good to implement since you don't want a fire or failure at sea. My wife is from Adelaide so I kinda understand the slang now.

If I did say something sounding Australian, it probably was an accident
Thanks

 

[Bop]

They are ideal for bifacials as you might imagine, with light being reflected from the water underneath the arch up onto the 'backside' of the panel, giving you a real boost in production compared to single sided panels, and unlike cabin mounted ones, are well away from the sails, minimising shading issues

 

[robbob2112]

Sorry Robbob. I am in US - Florida.

I was thinking of separating partly to get my head around and partly for redundancy.

I am planning to mount them close to the deck with perhaps a centimeter of gap for some cooling.
I was hoping to mount one over the dinghy davits since I have seen it being done a lot. However, I haven't seen one while at sea and wouldn't know how it handles in heavy weather.

If I did say something sounding Australian, it probably was an accident
Thanks

Now see - that makes a difference and I was soooo confused.... I blame @Bop for my confusion... kick a vic .... or something like that.

So, in florida - with two of these - https://www.currentconnected.com/product/victron-24v-multiplus-2000va/ (these only work below decks) -- just hook the cable between them and they put out 240v split-phase. Just a little configuration.... when hooking them together to the load panel the grounds and neutrals go together, and the line (black wires) go one to each side of the breaker panel. If one goes out the other can be reprogramed to function as a single and you can still have power to 1/2 your loads.

I do recommend current connected as a source since they actually have tech support and good ones. Signature solar has a mix of review, I have no personal experince with them.

If nothing is 240 on the boat at all you should be able to have them sync and just put out 120 and just wire across the two bus bars so you basically have two units running hot-hot or hot-standby .... read the manual for these and you will see what I mean.... no split phase this way...


As for cooling and weather there are specs in the manual.... minimum clearances around it.... might be worth taking a few pictures of other installs if you can to see what exactly they have done. There are a few units that are sealed against weather, they do cooling from heatsinks on the back... Probably ought to wait on @sunshine_eggo to make suggestions.

 

[tarch]

It means the combined Voc ratings of the panels can't exceed 100v (and personally, I have seen my own panels here in Australia go 15% past their marked Voc in the wrong weather conditions- I never go past 80% of the PVmax rating of the charge controller- it WILL dies sooner or later through a brief voltage excursion...)

The 15A is what its maximum OUTPUT is (not what the PV input current is) so on a 12v nominal battery bank, the limit for a Victron 100/15 is only 220w, and only 440w in total on a 24v nominal battery system so your controller is totally inadequate for TWO 400w panels (indeed it would struggle with only ONE 400W bifacial and would start clipping in good generating conditions with 400w coming in the front and 100w coming in the back even on a 24v battery bank...)

Got it. I can certainly go for a higher rated ones like https://www.amazon.com/dp/B07C6MSW12?th=1 and run the 24v battery like https://www.amazon.com/dp/B0C7G3YNV6?th=1 . Hyperion I linked seem to have much higher Voc compared to the MOBI you linked. Going with Hyperion for calculation sake, so over performing day with lot of sun, in series gives 70v and 15A input to the MPPT, leading to 24v * 50A on the output side to charge a 24v bank. Did I understand correctly?

View attachment 214367
(from section nine at Victron 100/15 specs)- your '1500w' is WAAAY off the limits of what they can handle... you are confusing the INPUT limit with the OUTPUT limit... a common mistake for beginners)

You have to remember the panels output ratings are ONLY at STC (standard test conditions) and when they aren't at those specific conditions (1000w/m^2 solar insolation, panel temp of 25C and atmospheric mass of 1.5 (the height from sealevel to the top of the earths atmosphere is 1AM) then its output can be lower (which is usual) or higher... (If the light levels go up, so does the voltage, if the temperature goes up, the voltage and power go DOWN, and if your boat is sailing on a mountaintop (what is it, the Ark lol) then the AM goes down and the power and voltage go UP...)
View attachment 214370
(see the STC ratings?)

Series arrays will generate more total daily power than parallel arrays- your MPPT controller may not even get into MPPT mode at all on a set of '12v' panels (thats salestalk, and tells us nothing) as it requires usually about 5v above the battery voltage before it even starts up (most will run in PWM mode before this- with the accompanying about 30% loss in generation) and many '12v' panels with a VOC of 18-20v may not get high enough 'loaded' (VMP rating of 16v-18v) to get 5v above the battery voltage until well into the day, or possibly ever!!!

Ah, didn't know that! Then again, there is a whole lot of solar I am wet behind the ear with! I will happily do 24 or even 48v that way, I can keep the wire guage and the charge controller costs a bit down!

If you are using the 400w Hyperions then the Voc is 37.07v, two in series will give you 72.14v Voc- which is actually almost perfectly matched to a 20% derated 100V charge controller (0.8 x 100v =80v)- these in nobodies right mind would be considered '12v panels' with a Vmp of 31v!!!

View attachment 214369
Shading a panel in series array reduces the array output yes, but so does shading a panel in a parallel array, and the added benefits of the series array (earlier start and finish times, both for charging and MPPT operation, plus better poor weather (overcast) performance by far makes up for it... but forget the Victron 100/15- you are looking at a 100v 80a minimum controller for a 12v battery bank, or a 100v 40a for a 24v battery bank- and both of those is running right at their upper limits- a 100v 100a on a 12v battery bank or a 100v 60A on a 24v would be less stressed in good conditions and a better choice... (with a potential 1000w of input coming in with two of those Hyperion 400w bifacials , your controller would be putting out 78.7a into a 12v battery bank and 39.3a into a 24v battery bank... the Victron 100/15 is seriously outclassed by these panels...

Bifacial panels require a good light source for the back (don't laugh- I have seen bifacial panels mounted FLAT and hard up against the roof of an RV- um how does light get to the back side of it???)- If you are planning a stern mounted array on the stern arch (especially if it 'hangs out over the water', then bifacials make a LOT of sense (reflected light from the water can get a major improvement in performance- indeed in some cases it may even pay to mount the panels upside down with the 100w side facing up and the 400w facing down!!!) but putting them on the cabin roof- forget the bifacials altogether...

I am not laughing at the mounting fiasco you mentioned above. Because, I was planning to do that. The panel on the dinghy davits will get plenty of reflected light and I knew the one on the deck will be mounted close to the deck and will sacrifice the 100W supposed to come from that side. It was just that I had them near me and cheaply. If I was going to pay extra for the bifacial, I don't think I will shell out only to put it in shade


I will sit this weekend and come up with a 48v system and see how this might work out. I can always use a step down converter DC-DC for laptops and other 12v needs.

Thanks all so far.

 

[tarch]

Now see - that makes a difference and I was soooo confused.... I blame @Bop for my confusion... kick a vic .... or something like that.

So, in florida - with two of these - https://www.currentconnected.com/product/victron-24v-multiplus-2000va/ (these only work below decks) -- just hook the cable between them and they put out 240v split-phase. Just a little configuration.... when hooking them together to the load panel the grounds and neutrals go together, and the line (black wires) go one to each side of the breaker panel. If one goes out the other can be reprogramed to function as a single and you can still have power to 1/2 your loads.

I do recommend current connected as a source since they actually have tech support and good ones. Signature solar has a mix of review, I have no personal experince with them.

If nothing is 240 on the boat at all you should be able to have them sync and just put out 120 and just wire across the two bus bars so you basically have two units running hot-hot or hot-standby .... read the manual for these and you will see what I mean.... no split phase this way...

Correct. I won't have anything 240v on board. So, I can go with the 120v.

As for cooling and weather there are specs in the manual.... minimum clearances around it.... might be worth taking a few pictures of other installs if you can to see what exactly they have done. There are a few units that are sealed against weather, they do cooling from heatsinks on the back... Probably ought to wait on @sunshine_eggo to make suggestions.

I can ask around in my area and see what others have done.
Thanks

 

[Bop]

I am not laughing at the mounting fiasco you mentioned above. Because, I was planning to do that. The panel on the dinghy davits will get plenty of reflected light and I knew the one on the deck will be mounted close to the deck and will sacrifice the 100W supposed to come from that side. It was just that I had them near me and cheaply. If I was going to pay extra for the bifacial, I don't think I will shell out only to put it in shade

Don't laugh, I mentioned before the motorhome (RV) that had bought the bifacial panels because they 'got more power' and then preceded to bolt them directly to the roof...
I was seriously struggling to keep a straight face when I diagnosed his 'lost power' issues- he simply didn't know (just had listened to a salesperson saying how they would 'make extra power over a single sided panel') and had mounted them like 99% of other Australians do on their caravans and motorhomes... flat directly on the roof...
I really didn't want to add insult to injury by laughing (or even smiling...) but...
it was a serious struggle not to....

 

[robbob2112]

Take a look at this thread and the others in the marine catagory. Seems like similar situation as yours.

Victron MPPT quantity for 4 panels

Hi We plan to add 4 panels on a 40fts catamaran sailboat to have around 1600W of solar for a 12V system (5 kWh LFP battery). I can use 1 or 2 or 4 MPPT for this project. It's just to choose between different Victron product (one 250/100 or two 100/50 or four 100/30). Remark that all those MPPT...

diysolarforum.com

 

[tarch]

Don't laugh, I mentioned before the motorhome (RV) that had bought the bifacial panels because they 'got more power' and then preceded to bolt them directly to the roof...
I was seriously struggling to keep a straight face when I diagnosed his 'lost power' issues- he simply didn't know (just had listened to a salesperson saying how they would 'make extra power over a single sided panel') and had mounted them like 99% of other Australians do on their caravans and motorhomes... flat directly on the roof...
I really didn't want to add insult to injury by laughing (or even smiling...) but...
it was a serious struggle not to....

Oh dear. I will be one of them soon then

 

[tarch]

Take a look at this thread and the others in the marine catagory. Seems like similar situation as yours.

Victron MPPT quantity for 4 panels

Hi We plan to add 4 panels on a 40fts catamaran sailboat to have around 1600W of solar for a 12V system (5 kWh LFP battery). I can use 1 or 2 or 4 MPPT for this project. It's just to choose between different Victron product (one 250/100 or two 100/50 or four 100/30). Remark that all those MPPT...

diysolarforum.com

Thanks Robbob. I will. And, I think I am going to go for LiTime 24v 100ah batteries https://www.amazon.com/dp/B0CSFYDQL9, #2 in series to run at 48v and https://www.amazon.com/dp/B07B36X8LP as the charger. I am looking at not running the AC much and see if a desiccant dehumidifier might be more suitable for the boat. I will try that first for now. As far as the panels go, I am thinking of sticking to the Hyperion and run them in series too. I can get some synchronous buck converters to bring the voltage to 12v at the distribution panel.

Hope I am not sounding like I know what I am talking about. Some but not all. So, if any gotchas, feel free to point out
Thanks