Considering going solar

[foggysail]

I meant special like ANL? Or just a regular breaker/fuse.

I cannot answer your question but interrupters should be checked for DC current breaking ratings. DC tough to interrupt especially if there is an inductor or measurable inductance in series with the current. AC is much easier because the current passes through 0 on each half cycle.

 

[firehoser75]

I had my solar supplier supply the breakers. They are mounted right next to the solar controller, about 2 feet from the batteries. I have 2 breakers specific to my solar system. One separates the panels from the controller, and one separates the controller from the batteries. Off hand I can't remember the amperage.

 

[mvweebles]

For one or two small panels, it's pretty straight forward on switches/breakers. But once you get into 400+ watts, you're into 30+ amps, so you have to start engineering the system to keep cable sizes manageable and breakers correctly sized. It's an exercise in Ohms Law (P = A x V) as you step down into the MPPT controller and into the boats charging system. It's not difficult nor is it complicated, but it does require diligence and sizing correct equipment. Solar systems usually use DIN switch enclosures which take a ton of space. Blue Seas makes some boat-relevant breakers but do not have sizes if you want panel mounts.

Bottom line is larger systems are still not that complicated, but the equipment changes compared to small systems. There is significant power being generated so you have to be careful. My 800w of panels will produce over 50A of charging power to the batteries. That's nothing to sneeze at.

 

[ScottC]

My 4 each 295 watt panels are connected with 2 parallel pairs connected in series. I can assure you that their output DOES NOT get killed with shade. Yes, the Vmp will be lower and the Victron controller adjusts to that change. Operating panels in series offers benefits. The higher output voltage relaxes the wire sizes needed from panels to the controller and for me that is a huge benefit.

In reference to FoggySails comment, I could have worded my post a bit better. Indeed, shadow from a tree, for example, will not kill the total array output 80-90%. It’s the placing of something like a RIB or fenders or something else directly on a portion of the solar array that kills a disproportionate amount of solar production, at least in my experience.



My array is actually composed of 3 pairs of panels. The two panels making up a pair are wired together in series and the 3 pairs are all connected together in parallel.

 

[ScottC]

That’s 22 amps at what voltage from 6 x 300 watt panels. On a good day you should see 120 to 150 amps. I have seen 25 amps at 12 from a single 330 watt panel.

My array is actually composed of 3 pairs of BISOL BLO-300 hard panels. The two panels making up a pair are wired together in series and the 3 pairs are all connected together in parallel.



MPP rated Voltage for each pair is 63.2 Volts at 25 degrees centigrade.
MPPT Controller is a Victron BlueSolar MPPT 150/45 TR (48V) 45Amp

Battery is a 48 volt LiPo which is generally fully charged to about 54.3 volts. 44 volts is "empty" for me. Too much risk of shortening the battery life to go below that. Battery is supposed to be good for about 8-10 years operating like this. I had to replace mine after about 9 years.


The entire installation is a factory installation, so I am assuming it was designed and assembled correctly.


Bottom line for me is that I can fully charge my 48v battery in two sunny-days' time while on the hook. This is with the 230v refrigerator and a (230v) 12v battery charger running off the inverter. This is good enough for me. Also interesting is that I can run at 2-3 knots on solar alone (i.e. with out negative draw on the battery) while running in electric mode. I admit, these solar-only speeds are not very exciting. They become more interesting for canal work and emergency "get-home" propulsion.

 

[Frosty]

I found 36" square panels of 200w each so have four mounted.

That would be a really convenient size for a project I'm doing (and not one I've seen). What is the brand/model or source, if you don't mind?

 

[mvweebles]

That would be a really convenient size for a project I'm doing (and not one I've seen). What is the brand/model or source, if you don't mind?

Slight correcction - they are 39" square. Rated at 200W. I purchased from a small solar shop in Price Utah. Looks like they are out of stock - give them a call. They were out of stock when I purchased last year so I had to wait a couple months. But like yourself, size was perfect so I could mazimize coverage on my hardtop

https://www.continuousresources.com...200w-36-cell-12v-nominal-solar-panel-5-busbar

 

[Ken E.]

That would be a really convenient size for a project I'm doing (and not one I've seen). What is the brand/model or source, if you don't mind?

Frosty, Since you're in the PNW, check Platt Electric. They have several stores in this region. That's where I got mine and they had a good selection, at least they did a couple years ago.

 

[Group9]

We have 540 watts of solar on our boat. That will run the refrigerator/freezer and recharge the loss from the night before, and that's about it.

 

[mvweebles]

We have 540 watts of solar on our boat. That will run the refrigerator/freezer and recharge the loss from the night before, and that's about it.

What's your battery capacity a d type of battery? Size of boat would also. E helpful.

 

[socalrider]

We have 540 watts of solar on our boat. That will run the refrigerator/freezer and recharge the loss from the night before, and that's about it.

That is surprising. Depending where you are, 540W of solar should get you close to 3,000W-h of energy, or about 10A x 12v x 24hr. Does your fridge/freezer draw 10A continuous? Mine is closer to 2A I believe.

 

[ScottC]

That is surprising. 10A x 12v x 24hr.

Are we planning on some arctic cruising? ;-)

 

[Group9]

That is surprising. Depending where you are, 540W of solar should get you close to 3,000W-h of energy, or about 10A x 12v x 24hr. Does your fridge/freezer draw 10A continuous? Mine is closer to 2A I believe.

My solar panels don't work 24/7.

 

[socalrider]

My solar panels don't work 24/7.

Geez... maybe file a warranty claim?

 

[mvweebles]

My solar panels don't work 24/7.

Ergo the question on battery capacity. The 24x10x12v response was to say your panels produce enough to fund an average 10 amp draw (240 ah per day, which is adequate for many cruisers with gas stoves, no AC or electric hot water, don't run their MFD systems for anchor watch, and no home theater systems aboard) , but you will need a reservoir to store the energy produced. As an educated guess, a minimum house bank of around 400ah for lead acid, 300 ah if lithium.

 

[Group9]

Ergo the question on battery capacity. The 24x10x12v response was to say your panels produce enough to fund an average 10 amp draw (240 ah per day, which is adequate for many cruisers with gas stoves, no AC or electric hot water, don't run their MFD systems for anchor watch, and no home theater systems aboard) , but you will need a reservoir to store the energy produced. As an educated guess, a minimum house bank of around 400ah for lead acid, 300 ah if lithium.

660 amp hours, AGM batteries.

It's not the battery capacity, I have plenty of that, it's recharging them with solar. I can run my AC off my batteries for a short time, but my solar would never make up that debt. There isn't enough room, nor enough good places on my boat to mount enough solar to do that.

I've had solar on my boats for years. Theoretical charging means little in real life, in my experience.

The theoretical maximum for our previous sailboat to my recollection was about 26 amps (280 watts). The most I ever saw, under perfect conditions, was 22 or 24 amps (I forget) briefly, sun directly over the panels, no clouds. Usually, due to the angle, I guess, I was lucky to get 14 to 16 amps.

I saw a lot of people when cruising with movable panels who had got tired of moving them all the time, and had just come to accept the loss of power from less than optimum angles.

I love solar, but my experience has been to expect about half of what a panel is rated for during daylight hours on average, when mounted on a boat.

I expect it to keep my fridge running at anchor without having to crank the genset, on sunny days. That's about the best I have been able to pull off over the years when cruising.

Others here, may be much better at it, than me.

 

[mvweebles]

660 amp hours, AGM batteries.

It's not the battery capacity, I have plenty of that, it's recharging them with solar. I can run my AC off my batteries for a short time, but my solar would never make up that debt. There isn't enough room, nor enough good places on my boat to mount enough solar to do that.

I've had solar on my boats for years. Theoretical charging means little in real life, in my experience.

The theoretical maximum for our previous sailboat to my recollection was about 26 amps (280 watts). The most I ever saw, under perfect conditions, was 22 or 24 amps (I forget) briefly, sun directly over the panels, no clouds. Usually, due to the angle, I guess, I was lucky to get 14 to 16 amps.

I saw a lot of people when cruising with movable panels who had got tired of moving them all the time, and had just come to accept the loss of power from less than optimum angles.

I love solar, but my experience has been to expect about half of what a panel is rated for during daylight hours on average, when mounted on a boat.

I expect it to keep my fridge running at anchor without having to crank the genset, on sunny days. That's about the best I have been able to pull off over the years when cruising.

Others here, may be much better at it, than me.

I have done three solar systems. One grid-tie on our condo in Mexico. Second a small off-grid for a friend's cabin in Wyoming. And now my boat's off-grid system. I can only speak to my experience:

1. Peak production means nothing - it's the average production that counts. My Mexico system is installed flat just like my boat - not optimized, with some slight shading early morning. On average, I get about 4.5x the rated panel power rating. This is over 2-years of data, so pretty solid.

2. Battery bank needs to be big. Even though my grid-tie array in Mexico is net-zero in the whole, over 65% of the power I consume comes from the grid. Said another way, 65% of the power I consume gets exported to the grid, then imported as consumption. Think of it yet another way, the Grid is essentially a massive battery bank. If I use 13 kwh/day, I would need a battery bank capable of storing/exchanging about 8.5 kwh, or close to 700AH 12V (for AGM, around 1400 AH), plus reserve, plus a margin to ensure the batteries can actually be charged during daylight hours.

3. Consumption needs to be carefully determined. Parasitic loads are surprisingly difficult to find and tamp-down. Any electronics sap more energy than I would have assumed.

At any rate, surprised at your performance experience. Sounds like you should be doing better than that. Even older home-style fridges consume less than about 100AH/day (12V inverter) even if run almost continuously. Unless you have some other stuff running and consumption is higher, I would think you would be able to consume and recharge 175AH each day. Sounds like you're well short.

For other's, Attached is an energy budget JPG to assist in power consumption calculations NOTE - XLS attachments not allowed in TF - PM me with email address if you'd like the XLS.

Peter

 

[Ken E.]

Peter, your AH numbers at anchor look good to me and they approximate my boat. As a verification, I need about 6 hours of 30 amp charging, which is a typical average for me on sunny days, to get back to float charging. 180 AH to restore to full charge is close to your 157 AH.

 

[denverd0n]

You will be told to figure out your amperage as suggested above but if you are lazy, don't. The reason I say this is you can't have too much solar...https://www.youtube.com/watch?v=SrIPvdw-zB4&t=135s

I would agree that you can't have too much, but you certainly can have too little. If he wants to replace his generator with solar then he needs to know what his usage is, in order to know whether or not solar will generate enough energy for him. If he only has room for 500 watts of solar panels, but his average consumption is 6,000 watts per day, then he is going to have to fix that generator!

 

[rsn48]

I would agree that you can't have too much, but you certainly can have too little. If he wants to replace his generator with solar then he needs to know what his usage is, in order to know whether or not solar will generate enough energy for him. If he only has room for 500 watts of solar panels, but his average consumption is 6,000 watts per day, then he is going to have to fix that generator!

For pure power, nothing can beat a generator. If your boat has a dishwasher and clothes washer and Jacuzzi, then you're hooped with solar (and Efoy). If you have a smaller boat as I do and you your goal is to be on the hook for a week or two, then solar/alternator/Efoy can provide that dream.

I have a separate refrigerator and freezer, two different locations that I had one inch insulation added surrounding the units to make them slightly more efficient. I swapped out my FLA batteries (four) and added 6 Firefly batteries (equals 12 FLA batteries). I added three solar panels, thinking of adding two more flexible jobbies on top of my Bimini, for 300 watts of solar. But remember up here in PNW & BC we get more sun than you southern guys. And of course much less in the winter. Today in Qualicum Beach, sunrise is 5:18 AM and sets at 9:26 PM (3 Jul 20). So my average amp/take per day per panel is higher than that same panel in Florida where in Miami the sunset/rise is 6:34 AM and 8:16 PM (3 Jul 20). Yeah us! But we won't discuss November, December and January into February in my location (why I added Efoy).

So assuming a 250 amp consumption per day, my solar will provide an average of 90 amps, running the boat will provide amps while underway, and Efoy can make up the difference if I am on the hook for longer than about four days.

With 6 Fireflies with a total amp load of 696 (lets say 700), I can go two days without anything supplementing my requirements. But remember during these two days solar has provided 180 amps, so I can go another day, but then another 90 amps has been added to the batteries during that third day, but by day three or four I will have moved the boat so the alternator will have added juice. Any shortfall the solar/Efoy can top up, and on and on and on. And Fireflies are like Lithium, they can charge up faster than AGM or FLA's.

 

[dhays]

I think there are to reasons to go solar for most folks. There are those that want to eliminate the need for a genset, and there are those that want to limits genset run times. I was in the latter category.

I had an almost 800 AH house bank that I wanted to keep charged up. I also was lazy and had a wife that is concerned about aesthetics so I really only had room for one well placed panel. So I spent big bucks on a high quality 365W panel. I still run my genset a couple times a day when out but the solar panel then is able to fully charge my batteries every day.

So, if you want to get rid of your genset, then do the work to figure out how much solar you need and round up. If you just want to lessen its run time to keep the batteries fully charged, then just throw as much solar on as you can conveniently do and afford.

FWIW, it is currently heavily overcast. My single panel is putting out 100W at the moment. A bit early with a lighter overcast cloud cover, it was putting out over 300W.

 

[AMG]

Very interesting read, I am quite new to the boating World please excuse me if this seems a silly question, was wondering how the solar charger works with the shore power, can you set it so that when on shore power the batteries are maintained, fridge run with solar and then when the sun goes to bed the shore power kicks in?

 

[rsn48]

Why wouldn't you just run everything from shore power when at a marina? Is your fridge AC? Though many generations of Canadian I am, my Scottish heritage kicks in when I'm am at a marina for a night or two and I've paid with electrical included, then I have shore power on full time to run everything that is on and to charge the batteries.

 

[AMG]

Why wouldn't you just run everything from shore power when at a marina? Is your fridge AC? Though many generations of Canadian I am, my Scottish heritage kicks in when I'm am at a marina for a night or two and I've paid with electrical included, then I have shore power on full time to run everything that is on and to charge the batteries.

My shore power is not included, but I’m really just wondering about it not planning anything at the moment, I wonder if there is a battery charger that uses the solar but if not enough clicks over to the shore power.

 

[dutch-barge]

AMG

On one of our boats we have 1600Win solar panels, connected with 2 Victron Moppet's to a 24V battery bank, to which we connected 2 300W Victron inverters.
The solar keeps us alive throughout the year. In summer when the fridge is running, the washer/dryer runs 1 - 2 times a week we heat the water for nice showers etc, we are usually fully recharged by midday.
During winter now and then we have enough snow to negate any solar input,. The Victron inverters can be programmed to accept shore power when the State Of Charge (SOC) of the batteries drops below a set level. ( we have it at 80)
we also have the inverters set when we are onboard to fully let solar charge the battery, then use any excess solar to heat the 2nd hotwater heater be heated by the solar as long as the SOC does not drop below 90. ( our other hot ware heater is a diesel constant water heater...for the Lon long showers)

 

[koliver]

660 amp hours, AGM batteries.

I can run my AC off my batteries for a short time, but my solar would never make up that debt. There isn't enough room, nor enough good places on my boat to mount enough solar to do that.

I expect it to keep my fridge running at anchor without having to crank the genset, on sunny days. That's about the best I have been able to pull off over the years when cruising.

Do you mean Air Conditioning? or Alternating Current?
If the former, there is no way you an expect your solar to supply the required energy.
If you mean Alternating Current, you haven't given us any data to know your AC demands, so we have no idea what the total budget would be.

I run a fridge and a freezer, both DC, and my solar will easily keep up with all m power demands, with a pair of 160w panels. The batteries are always fully charged long before the sun goes down and never too low in the morning.

 

[Xlantic]

I am currently increasing the number of panels. For the last two seasons I had three 330 W nominal capacity panels for a total of almost 1 kW. I am now adding three more panels for a total nominal capacity of almost 2kW.

With the 1 kW nominal power I hardly used the generator. Only once, after a few days on the hook with overcast days, did I need to run it and only for a couple of hours. (Gas cooking and no AC or electric water heater when anchoring. Washing machine and dishwasher but no dryer.)


The first three panels I had were mounted on the original Bimini structure which I reinforced with additional tube supports. (This set-up was adequate if a bit bouncy.) So the panels served a double duty: solar power and shade in the flying bridge in lieu of a Bimini top.

This summer I decided to add three more panels more for additional shade in the fly than for more power, although more power is always welcome. I designed and had built an aluminum structure to hold the panels (see below, upside down).

What to do with all the extra power? Maybe AC for after-lunch naps and water heating. I also plan to eventually get an electric motor for the dink to avoid having to carry gasoline.

(The first three panels were connected in series for a maximum of 120 V and the six panels will be connected in three sets of two panels each, in parallel, with the three sets in connected series, also giving 120 V max. The regulator is a Victron MPPT 150/70.)

 

[Patrick4002]

i live in europe where the sun is not always max.
the last 3 years i expermented on my previous boat to learn the use of solar panels in a stand alone grid (no shore connection)
We cook electric, have 2 fridge sat tv heating on fuel and no airco
the usage was just over 3kw/day

ther are 3 parts on a solar system that hase to be right dimentions for a good daily work. (sorry for the bad englisch)

We have from dec 2019 a trader 54 with a lare roof on the back side
we want to add a waching machine and elektric oven on the user list of our system so we will go to 4.5kw daily use.
we have airco on board but tis need a practical approach.

to get the nessecairy power for a daily living (for 10 months a year good sun) we have placed a 24 m2 solar panels or 2400w of panels connected in 2 grids with each there mppt battery loader
Normal battery last max 4 years on a daily use, so we instaled a 7kw 24v full traction batery pack, attention was needed for the explosif gas when charging so thes is a exhaust eex ventilation installed who is automatic started when charging is getting at 27,8V

the invertor is a 500w cont. 7500w /5sec to give us the 220v

the boiler is now heating from 11am to 1h30pm the airco is only used on hot sunny days from 1pm till 7pm washing machine only when no airco from 1h30pm

to opperate all the aircos on the boat i have to start the generator as they use 10kw

I save a lot of shore power wich is expencive in Europe so i win back the installation in 2 years

life expectency 220v invertor - 10 years, solar panels/mmpt loaders 8 years,
full traction battery pack(the expencive part) -12 years

The heating in the winter is still the most expencive part for us

Best regards,
Patrick

 

[bottomsjohn]

The above comments are the best that I have ever read in one place! My wife and I lived aboard a motorsailer six winter months for 15 years in the Bahamas at anchor only without a generator. We had about 1350w of panels, 5 8D gel cell batteries in one bank, a large chest style efficient fridge, a 100w 12 VDC hot water element, Spectra water maker, but used little electricity otherwise. We never drew our batteries down more than about 15% which contributed to there long life: batteries had 80+% capacity when we sold the boat after 20 years! This frugal lifestyle would suit few cruisers.

A suggestion would be to have your generator fixed with your learning how to maintain it if it not too expensive. In addition add as many panels as will easily fit on your boat.
It takes a lot of unshadowed roof space to collect all the amps you may require.

A few hundred watts of solar combined with your generator will insure that your batteries are 100% charged almost every day. Even if you discharge your batteries as much as 40-50%, fully charging them daily will about double their life. My goal was to not have to wrestle the five 8D monsters out of the bilge! Charging batteries with a generator is helpful for a 90-95% bulk charge, but solar reigns for getting in that last critically important 5-10% for long battery life. If you do not mind replacing batteries every 3-4 years, fixing up and maintaining your gen might be the easiest and cheapest way to go depending on how long you own/use the boat.

I found that few to no boat buyers value solar over a gen. A large solar bank requires frequent daily observation since a failed regulator can cook expensive sealed batteries!
Good luck on your decision for what is best for you.

 

[rsn48]

I found that few to no boat buyers value solar over a gen.

This is changing as we become more aware of alternate power, not only for our boats but our homes as well. In the PNW and BC coastal areas, more of us want to gunkhole and be on the hook longer without the noise and smell of a generator. I'm always reluctant to generalize to other geographic areas as how we boat can be so different. Up here in God's country with the occasional raindrops, owning a center consul boat is just plain a waste of good money (talking about 30 feet plus consuls) but I do get it for folks down south.

Jeff Cote, the owner operator of Pacific Yacht Systems has been presenting solar at the Seattle and Vancouver Boat shows for a number of years so some of the folks who heard him five years ago are starting to come around to solar as their desire to be on the hook longer increases. All of us introverts who don't want to be around the "Maddening Crowd" seek out more isolated anchorages.

Between my boats alternator, firefly batteries, my solar and if I took 6 canisters of methanol fuel (roughly $600 + for the methanol fuel), I could be on the hook for two months without requiring any marina shore power support, assuming an average draw of 250 amps/daily. Now before some one says the Efoy methanol canisters are pricey, yes - you are right. But what is your marina bills as you boat marina to marina, I bet more than $600.

If I were doing the great loop, and warning, I know next to nothing about the loop so that makes me an expert. But I assume (with all the negatives that word implies) that gunkholing isn't as much a thing when you are powering down a river. I "assume" going down the river is more a marina to marina thing. If you are taking your boat from LA to Catalina Island solar (and Efoy) is probably a waste.

My first owned boat was an older Catalina 27. When the Catalina guys were manufacturing these early sailboats, they came without an anchor locker or shower in a head that was reasonably roomy for a 27 foot sailboat. Of course the vision was the Catalina boat owners would sail marina to marina, why would you possibly want an anchor on your boat. There is a Washington/BC Catalina's Owner group up here and one of their tutorials you can access is "how to add an anchor locker to your 27 foot boat." It wasn't until Washingtonians and BC'rs started purchasing the 27 foot wonders and whined about lack of a proper anchor locker that lockers were added. Boating varies so much from region to region.