Solar panel upgrade questions

[Submariner]

If you're not sure what your average consumption is on your boat assume 80-100ah a day as a starting point. The cabin refrigerator will consume about 20-30ah, daily. The cockpit refrigerator is about 12-20ah daily.

Some us are 'lucky' enough to have boats so small that they only have one refrigerator. Look at all that power that we save!

We love our cockpit refrigerator. It's our drink cooler so we don't usually carry an ice chest onboard. But having that cockpit refrigerator there is an electrical tax we pay, for sure.

 

[cruiseoncraig]

On Channel Surfing, an RT27-OB, I upgraded solar in May 2021.

I removed the factory CMP (Custom Marine Products) 160 watt solar panel and replaced it with a pair of CMP 200 watt panels. The panels are fixed/rigid panels, monocrystaline panels, with an efficiency of 23.7% using SunPower Maxeon cells.

I have 400 watts total and I connected the two panels in series and upgraded the solar controller from a PWM controller to a Victron MPPT 100/30 controller.

This is real-world data I've captured over the past 15 months of solar on Channel Surfing around the Pacific Northwest, year round.

I've done the math in the spreadsheet to proportionally downgrade or upgrade my actual numbers to a smaller or larger wattage panel. The idea is to help others get some insight to what you might expect with a different sized solar array.

Obviously, solar depends on the weather, rain, fog, overcast, clear blue skies... and time of year, January, March, July, all cause drastic variations in output.

But consider this... If you have 100amp-hours a day in your battery bank and you consume 100amp-hours a day, you get 1 day away from shorepower. But if solar were able to provide you with 75ah a day, you now get 4 days.

If you're not sure what your average consumption is on your boat assume 80-100ah a day as a starting point. The cabin refrigerator will consume about 20-30ah, daily. The cockpit refrigerator is about 12-20ah daily.

Solar wattage comparison spreadsheet
https://www.letsgochannelsurfing.com/solar-power?pgid=kxcvhybj-984f2fdc-512b-4708-af84-e932b613eda6

Hi Martin,
I have two 125 watt Kyocera panels and the Morningstar controller that came with my 2015 C28. The controller accepts two panels and we wired them in parallel, that is, we did not daisy chain them but wired them individually. After reading some of your and others posts, I'm wondering if I would get more production by switching to the Victron MPPT controller?...and which would be best, parallel or series. In case you can't tell the technical side of all this comes into my brain and turns to oatmeal.

 

[cruiseoncraig]

Hello Again Martin, I have four LifeLine AGM's that I'm pretty happy with, they seem pretty robust. However I am not happy with my charging situation. The internally regulated alternator has an unprogrammable charging profile that does not come close to pushing these batteries. I am contemplating going to Balmars programmable regulator and pushing them a little harder. I am also considering installing a fan behind the alternator to help cool it off so it doesn't dumb down so quickly from heat, I've heard good things about this. If that doesn't please me I am considering installing a Balmar XT hairpin stator 250 amp alternator. One of the fears of doing that is putting too much side load on the water pump due to increased demand, but then I read that is more of a problem with V belts vs. Serpentine belts. Your thoughts?

 

[Submariner]

Hi Martin,
I have two 125 watt Kyocera panels and the Morningstar controller that came with my 2015 C28. The controller accepts two panels and we wired them in parallel, that is, we did not daisy chain them but wired them individually. After reading some of your and others posts, I'm wondering if I would get more production by switching to the Victron MPPT controller?...and which would be best, parallel or series. In case you can't tell the technical side of all this comes into my brain and turns to oatmeal.

MPPT solar controllers are about 20% more efficient than PWM style controllers. Said differently, upgrading your Morningstar controller to an MPPT controller would get you 20% more solar power from the panels you already have.

If you have no shading issues at all on the solar panels, then series is preferred. Wiring in series also requires that you have a solar controller that supports the higher voltages (this pretty much requires a MPPT controller). Else, wire them up in parallel.

 

[Submariner]

Hello Again Martin, I have four LifeLine AGM's that I'm pretty happy with, they seem pretty robust. However I am not happy with my charging situation. The internally regulated alternator has an unprogrammable charging profile that does not come close to pushing these batteries. I am contemplating going to Balmars programmable regulator and pushing them a little harder. I am also considering installing a fan behind the alternator to help cool it off so it doesn't dumb down so quickly from heat, I've heard good things about this. If that doesn't please me I am considering installing a Balmar XT hairpin stator 250 amp alternator. One of the fears of doing that is putting too much side load on the water pump due to increased demand, but then I read that is more of a problem with V belts vs. Serpentine belts. Your thoughts?

What size is your house bank (how many amp-hours)? What size is your alternator (in amps)? Adding a dedicated alternator with an external voltage regulator for just the house bank would make sense to me. The Lifeline's will take up to a 5C charge rate which is pretty impressive for AGM.

I'll be adding a couple of Lifeline batteries to my boat probably next season (AGM engine starting and AGM thruster bank).

 

[Rode Trip]

I have to disagree about the parallel vs series wiring of solar. Parallel is always preferred to series. Rod Collins, the electrical guru behind Marinehowto.com did some experimenting and was able to prove that parallel outperformed series in every situation. He never wrote this up in an online article but he did on his facebook electrical group. I'm going to repost below what he wrote in the group after his experiment.

Rod Collins
·
Solar Series vs. Parallel on a boat-

Seems to be a lot of myth and lore around Series solar on boats..We tested this extensively with Amy B. of AltE. Eventually this will become an article on Marinehowto.com..

I came up with this testing design to have a fair comparison under ideal & identical conditions. One day wile talking with AmyB of AltE I ran this by her & she could not wait to be involved and even offered to supply the panels..

- We used two Morningstar MPPT controllers (also repeated with Victron MPPT controllers *we are a Victron dealer AlT E was not)

- One set of panels was set up for parallel and one for series in an X pattern wiring layout

• All panels were set up flat, as they would be on a boat, and we wired them in the X pattern, as below, with identical wiring harnesses right down to the MM lengths. Harness volt drop was tested using an electronic DC load to be sure both harnesses were the same..
• Shade was induced 100% equally to all panels by placing a BBQ rotisserie motor smack dab in the middle of the 4 panels with a single 3" wide, rotating paddle rotating 36" above the panels to mimic a sailboat with shading.

- Solar performance was tracked with a dual-shunt Bogart Trimetric that was carefully calibrated- Panels / controllers were placed in a large completely un-shaded field and connected to a 98% discharged 400Ah LiFePO4 battery. The controllers were wired in parallel to the load each with its own shunt. The LFP battery was used as the "load". Under no testing scenario did the panels ever get the LFP bank to absorbtion voltage pure bulk charging the entire time.

- Genuine Multi-Contact MC4's were used. ( not poor performing knock-offs)

Most of the data was collected by Amy B of AlT E at our property in Maine. (She was a neighbor of ours up at the mountain.)

Not once did series beat parallel. The closest day was a day when series delivered 97% of parallel..

This is an easy and fair test to conduct yourself all you need is four identical panels an Ah counter and a BBQ rotisserie.. When we conducted this with four semi-flex panels with no bypass diodes the spread between series and parallel was even wider but not much..By-pass diodes made little quantifiable difference . I thought it would have been better

 

[Submariner]

• "Shade was induced 100% equally to all panels by placing a BBQ rotisserie motor smack dab in the middle of the 4 panels with a single 3" wide, rotating paddle rotating 36" above the panels to mimic a sailboat with shading."

• "When we conducted this with four semi-flex panels with no bypass diodes the spread between series and parallel was even wider but not much..By-pass diodes made little quantifiable difference . I thought it would have been better"

If there is a shading issue, parallel will outperform series. He purposely induced shading in his testing. A solar panel is constructed of cells, all connected in series. Connect two panels together via series makes one big panel. Connected in parallel makes two separate panels that operate independent of each other. The R27-OB has zero shading issues, the mast doesn't ever cast a shadow over the panels. Some panels are shade resistant as well, as they offer electrical bypasses that reduce capacity but still allow power to be generated by the remaining unshaded cells. Rod's observation that the bypass diodes didn't make much difference was interesting. I hadn't heard that before.

If I had a sail boat with a big mast in the middle I'd run a port and starboard panel, each with their own dedicated solar controller as I would expect at least one side to be completely shaded most of the time.

The pair of 200 watt panels I installed are Custom Marine Products Mono cell panels. They renamed and re-marketed them as 210 watt panels (same exact panel) as they were outperforming their original 200 watt spec. My two panels are connected in series. I broke my high-score for solar this season. 416 watts peak on one day. Then about a week later I hit 2,730 watt-hours (213 amp-hours at 12 volt) breaking my old record of 2,700 watt-hours.

https://www.letsgochannelsurfing.com/boat-upgrades/solar-panels?pgid=lmydgcq5-b6c9c0_6c3e048369ff4e5ebe6d29b9045f7d0fmv2.jpg

 

[scross]

Real world example of benefits of upgrading solar. Been on our Broughtons cruise for 15 days now. Average time underway between locations about 40-45 minutes. Cruising at 2,400 to 2,700 rpm. Used shore power 3 nights and one of those was completely unnecessary.
Average solar panel output 900 watt-hours or 75 amp hours at 12 volts. We have a power hungry portable freezer in cockpit that sucks up about 55 amp hours a day.
We have had lots of sunny afternoons but mornings until noon and late afternoons after 7 PM are foggy. Plus 3 days of heavy rain.
I could have avoided the shore power altogether by picking docks or anchorages a bit further apart. Given that shore power up here averages $25 USD a night it would have been more economical to burn more fuel.
That said, the solar contribution to my house bank lets me anchor out or use docks w/o shore power multiple days in a row. That gives me a lot more flexibility in cruise planning.
My $600 upgraded solar system has almost paid for its cost after 2 full seasons. Next season I’ll be in the black!

 

[Rode Trip]

Seeing these solar panel results has me convinced to add a solar panel as my first electrical upgrade, before improving the battery capacity.

Unrelated, but scross how are you able to 'like' posts? You're the only one I've seen do it and I scoured the posts looking for some option and can't seem to find it.

 

[scross]

Seeing these solar panel results has me convinced to add a solar panel as my first electrical upgrade, before improving the battery capacity.

Unrelated, but scross how are you able to 'like' posts? You're the only one I've seen do it and I scoured the posts looking for some option and can't seem to find it.

Andy, im using the website, not the app. On an iPhone. Here’s what I see at the bottom of each post.

 

[Rode Trip]

That's weird, I'm using a computer and it's not there. Checked on my iphone and it's not there either. I guess that's why you're the only one able to 'like' posts. 🙂
edit: Submariner can do it also, maybe I'm just too new and don't have permission yet.

 

[SeaWoof]

Just to chime in on the advantages of some of the newer bi-facial panel (one that captures energy from both sides), since rangers have space under the mounting point and the boat has a white roof (perfect for reflection + reflection off water). You can get maybe 20-30% more power out of the panel. So combine this with a much more efficient MPPT controller (~20% more efficient) and you are looking at a potential gain of up to 50% from the standard panel and controller - from the same footprint (theoretical of course). That is pretty impressive.

 

[freedomvango]

pretty sure i can fit 1000w+ on the front of almost any tug, even more extending over the bimini. My goal is to run the AC in the summer in Florida off solar during the day. On my van my 1000 watts gives me about 70 amps which is enough to run that, using not great panels. Screenshot from my VRM when I last used that van to show production

 

[4umfreak]

400w panel on a 100/30 and a Thule box. fi
Fits good on a 2011 r27. No shading issues. They both hang over the bimini a bit but don't touch it.

What to do about that fugly tv antenna though?

 

[Ted Rathjen]

So much information, thank you. We live in New England our boat is a 2013 R27C. We’ve decided to use our mooring this year which we own. We have a single panel which I believe is factory. We have a generator and will be upgrading the batteries this spring with AGM’s. We keep the refrigerator operating most the time to keep the bevies cold. We are conservative with electric when onboard, if we need ac we run the generator. Propane for the bbq and rarely we need heat. When operating big draw items like the oven we use the generator. We’ve upgraded all the bulbs with LED. I’m concerned if our panel will be adequate to maintain the batteries while on the hook. I’m a DIY guy for the most part but electrical, especially routing cables on the boat is incredibly difficult. First should I be concerned with limited solar? Second if we upgrade how difficult is the process and can we use the factory cables. Third, anyone have recommendations for our model from recent upgrades.

 

[freedomvango]

Untitled by Grant Wilson, on Flickr

First 600 installed. rack is being built to replace the proof of concept rack, and will extend over the bimini for 600 more.

 

[Ted Rathjen]

MPPT solar controllers are about 20% more efficient than PWM style controllers. Said differently, upgrading your Morningstar controller to an MPPT controller would get you 20% more solar power from the panels you already have.

If you have no shading issues at all on the solar panels, then series is preferred. Wiring in series also requires that you have a solar controller that supports the higher voltages (this pretty much requires a MPPT controller). Else, wire them up in parallel.

Good morning Martin. I’m slowly understanding from the panels to the controller. This is the part I’m stalled on. My current system on my 2013 R27 classic panel is a KRYOCERA 140 SX. The controller is a Morning Star Sun Saver Duo SSD-25 rated for 25 amps. The sun saver has the solar input and 2 pair out. I also have 2 BlueSea SI-arc start isolation automatic Relay. The 2 pair appear to connect to the BlueSea. Looking at the Victron 100/50 I only see only 1 output. My confusion is how to connect from the controller to the house batteries and do I need to go through the BlueSea isolation.

 

[Rode Trip]

Good morning Martin. I’m slowly understanding from the panels to the controller. This is the part I’m stalled on. My current system on my 2013 R27 classic panel is a KRYOCERA 140 SX. The controller is a Morning Star Sun Saver Duo SSD-25 rated for 25 amps. The sun saver has the solar input and 2 pair out. I also have 2 BlueSea SI-arc start isolation automatic Relay. The 2 pair appear to connect to the BlueSea. Looking at the Victron 100/50 I only see only 1 output. My confusion is how to connect from the controller to the house batteries and do I need to go through the BlueSea isolation.

I'll explain how I'm doing my installation from scratch and it might help you. I'm installing two (2) 200 watt bifacial panels on the roof racks and a Victron 100/50 MPPT. I'm connecting the panels in parallel on the roof and running 10 awg wire the short distance to the MPPT in the cabin (28 volt open circuit max, 24 volt operating panels, 9.3 amps max each). I'm putting a 30 amp breaker right before the input to the MPPT on the positive leg just to use as a switch if I need to service the system later. From the MPPT I'm running 6 awg (maybe 4 awg, need to get more exact measurement of length) wiring directly to the house battery. I will probably connect the negative wire directly to my battery monitoring shunt and the positive directly to one of the two house battery positives. I plan to install a 40 amp MRBF fuse on the house battery positive so that the overcurrent protection is within 7 inches of the battery.

 

[Ted Rathjen]

I'll explain how I'm doing my installation from scratch and it might help you. I'm installing two (2) 200 watt bifacial panels on the roof racks and a Victron 100/50 MPPT. I'm connecting the panels in parallel on the roof and running 10 awg wire the short distance to the MPPT in the cabin (28 volt open circuit max, 24 volt operating panels, 9.3 amps max each). I'm putting a 30 amp breaker right before the input to the MPPT on the positive leg just to use as a switch if I need to service the system later. From the MPPT I'm running 6 awg (maybe 4 awg, need to get more exact measurement of length) wiring directly to the house battery. I will probably connect the negative wire directly to my battery monitoring shunt and the positive directly to one of the two house battery positives. I plan to install a 40 amp MRBF fuse on the house battery positive so that the overcurrent protection is within 7 inches of the battery.

I'll explain how I'm doing my installation from scratch and it might help you. I'm installing two (2) 200 watt bifacial panels on the roof racks and a Victron 100/50 MPPT. I'm connecting the panels in parallel on the roof and running 10 awg wire the short distance to the MPPT in the cabin (28 volt open circuit max, 24 volt operating panels, 9.3 amps max each). I'm putting a 30 amp breaker right before the input to the MPPT on the positive leg just to use as a switch if I need to service the system later. From the MPPT I'm running 6 awg (maybe 4 awg, need to get more exact measurement of length) wiring directly to the house battery. I will probably connect the negative wire directly to my battery monitoring shunt and the positive directly to one of the two house battery positives. I plan to install a 40 amp MRBF fuse on the house battery positive so that the overcurrent protection is within 7 inches of the battery.

Your description was excellent. Thank you. I’m attempting to source a single panel larger than I currently have something around 300+/- watts. Other than our refrigerator and bilge pumps while on our mooring I don’t seem to need more than I’m planning on. . We’re fortunate to have a generator aboard that runs the house as needed. This Tug family is so generous with their time and expertise. I’ll let you know how I do. Ted

.

 

[Submariner]

Good morning Martin. I’m slowly understanding from the panels to the controller. This is the part I’m stalled on. My current system on my 2013 R27 classic panel is a KRYOCERA 140 SX. The controller is a Morning Star Sun Saver Duo SSD-25 rated for 25 amps. The sun saver has the solar input and 2 pair out. I also have 2 BlueSea SI-arc start isolation automatic Relay. The 2 pair appear to connect to the BlueSea. Looking at the Victron 100/50 I only see only 1 output. My confusion is how to connect from the controller to the house batteries and do I need to go through the BlueSea isolation.

The SunSaver duo is a PWM style controller. Just switching to a MPPT style controller (more efficient) will result in 20% more power from sunshine on the existing solar panel you have. The PWM style controllers were really designed for low wattage solar arrays as the PWM controller uses very little power. An MPPT controller also uses little power, but it uses more than a PWM consumes.

Most MPPT controllers that I've seen available only output to a single battery bank. The SunSaver Duo is configured for 90% to the house, 10% to the engine battery. Personally, I don't think this is necessary. On a NW edition boat using all AGM or FLA batteries.. those SI-ACR's, with enough sunshine, a charge voltage is created causing the ACR's to close, which means sunshine will get to all three battery banks. On folks with a Luxury Edition (using LiFePo4 batteries), then the output of the MPPT controller just goes to the house bank. EPever makes a MPPT controller that will send 90% to the house and 10% to the engine battery. This is what's standard on the NW editions today that Fluid Motion is selling on the new boats (A 20amp EPever is what the factory uses today). Again, I don't think it's necessary to have dual outputs (house and engine). It doesn't hurt to have dual-outputs.

When I re-wired Channel Surfing and converted my NW edition to LiFePo4 (LFP), I went with a 150/30 MPPT Victron SmartSolar controller. I've since replaced it with a 100/35 Victron controller. I have two 210 watt solar panels (420 watts total). It serves us well, with no generator on board. My MPPT controller outputs to the House bank and that's it. My thruster and engine battery get charged on shore power or when the engine is running. I figure, my car sitting in my driveway for the 55 days we were gone to SE Alaska, started up fine upon our return. The only use case I can see where maybe having the MPPT controller with dual outputs to the engine and house battery is if we trailered our boat and stored our boat for long periods of time on the trailer without shore power. But then again, if that was storage on a trailer without shorepower, I'd probably bring the engine and thruster battery home to my garage for the off-season.

I also want to note the following. A PWM style controller requires that the voltage of the solar panel match the voltage of the battery bank. Our boat is 12volts, and the original solar panel that came on Channel Surfing was a 12 volt 160 watt panel. The 210 watt panels I put up are 24 volt panels. Larger panels most often are going to be 24volt (some are 48 volt). The MPPT controller is a battery charger, while a PWM controller is more like an on/off switch. Said differently, if you're going to upgrade solar on your boat, always start by upgrading the controller first since it's likely that whatever panel you go with, you'll need a MPPT controller for compatibility with the new panel you put up. I started by upgrading from PWM to MPPT, and 5 months later I did the solar panel upgrade.

I have a ton of info published all about solar on our website.

Solar Panels | LetsGoChannelSurfing

www.letsgochannelsurfing.com

And also over on YouTube. Here's a playlist of all our "Solar on a Boat" videos.

Solar Power on a Boat

Share your videos with friends, family, and the world

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