Solar system - 'real world' help needed!

[roland stockham]

Hi All
I am not currently cruising full time but make extended trips (2-3 Months) and may not have shore-power when docked
Just looking at ordering the parts for a solar charging setup and need some advice from people who have used this stuff, it's my first system! have read all the bumph and many threads on here but if you have experience with solar could you look over the system and comment. Thanks

Boat. 35ft classic, Radar, small fridge and autopilot are main consumers and all lights etc are LED. Nav is by tablet and only on for coastal. From experience I use 50-75a/h per day. This may go up a bit as I have just installed a more powerful pilot but I also have a wind vane. I occasionally get up to 125 when running nav, auto pilot and radar 24-7 plus making lots of coffee!!! (the electric kettle gets used when it's iffy and I can't stay below to work the stove).
At the moment I find that, on a long run, I don't have the engine on for long enough to fully charge the batteries so they go down to about 85% and stay there, bad for the batteries and reduces power available if it is needed.
Electrics. Externally regulated 90a alternator, 2 batt banks one about 350a/h for domestics, one 300a/h for nav and ships gear. 3 way diode to batteries. Charge acceptance with low batteries is greater than the alternator will produce (about 70a at 2000rev). I am happy to continue to use the alternator for bulk charging if needed.
What I want the solar system to do is;
1. Keep/recharge batteries when the boat is unattended
2. Reduce engine run time so that normally I will not need to run the engine either underway or at anchor.
3. If I have used more power and need to run the engine I want to do the bulk charge in the morning from the alternator but for the solar system to then get the batteries back up to full charge during the day.

The system I am looking at is a 245w Kyocera panel and SOLARBOOST3000i 30A 12V MPPT PV CHARGE CONTROLLER.
Questions
1 Can I hook the panel to the diode block on the alternator input, does the controller have remote batt sense or can it be adjusted to compensate to the diode voltage drop (about 0.75v)?
2 If I get a second panel will I also need a bigger controller? What happens if the panels occasionally produce more than 30a, does it simple limit the current or will it blow the controller?
3 In the real world sailing from Panama north to Canada what am I likely to get in A/h day from this panel? Do you think it will be big enough? I am guessing I will get about 60% rated output for 6h/day with a peak of about 90% allowing for sun angle and transmission losses, is this about right?
4 I have seen various controllers on Ebay as direct purchases from China which would save $100-200. I have had good results buying LED lights that way but anyone used controllers from there and were there as expected?
5 Do people rig panels so they can be taken down for storm conditions or will they stand up to 50kn if well mounted?

I may be able to fit a second panel if needed but getting concerned about windage and loading on the stern arch if I do. It would also be over the stern above the rudder and windvane so a bit vulnerable. Some extra windage will be good as she has a high bow that tends to blow off.

[Snore]

Curious-- a 240 is big. Where would you mount it?


Sent from my iPhone- please forgive autocorrect errors.

[sailormed]

The 245W panel, mounted fixed horizontal is going to produce 70% of 245 = 170W. 4 hours of daily sunpower production (4 hours @ 100%, you get more sunhours in a day, but most are < 100%) = 680W. Theoretically you can get 680/12= around 56 Amp hours daily on sunny days. For you to decide if this is OK for you. If you can orient the panel to face the sun (difficult when on a mooring) you could get more Wattage out of it.
Your 30A MPPT could possibly support a second panel, it is a bit close to the limit for 2 panels.

[roland stockham]

Originally Posted by Snore

Curious-- a 240 is big. Where would you mount it?

As an extension to the stern arch, it is about the same width. Once you get above 200w you are using panels made for home instalations in much bigger quantities so the price per watt is about half. 140w panel $290, 245w $310!

[BobLoucks]

I am looking to do a similar setup.
I am looking at a 305w solar panel from Canadian Solar for a bimini mount, https://dnmsolar.com/product.php?pro...FRCGaQodfQULMw
About $285 Cdn dollars so deduct about 40% for USD.
300w pure sine inverter
30amp charge controller.
Also looking for advice & feedback.

[holtjp]

My boat sounds a lot like yours in terms of size and daily power requirements. I tried to work with larger panels for cost and efficiency, but simply could not make them fit. The amount of unshaded space on a 35 foot monohull is pretty small to begin with. On top of that, the larger full-frame panels presented quite a barrier to movement. I ended up returning the larger rigid panels and I am still working to fine tune the installation of 2 x 100W and 2 x 50W flexible panels. After one full season, I do have some concerns with the 100W flexible panels, but this is the only route open on my boat. Check and double check the proposed location for your panels for both width AND thickness.

[roland stockham]

Originally Posted by BobLoucks

I am looking to do a similar setup.
I am looking at a 305w solar panel from Canadian Solar for a bimini mount, https://dnmsolar.com/product.php?pro...FRCGaQodfQULMw
About $285 Cdn dollars so deduct about 40% for USD.
300w pure sine inverter
30amp charge controller.
Also looking for advice & feedback.

That looks like an excellent deal if they are not to far away. Unfortunately for me the freight costs to get it to the boat would be more than the cost of the panel! Why are you looking at pure sign for the inverter, only thing that I have found that needs it is a microwave. At the price they are may be worth getting a small one just for a specific device and then a bigger one for the main circuit. If you mount the panel as a bimini remember to ensure it is not under the boom or you will loose lots of power.

[reed1v]

We used an inwater prop generator while underway that charged at 10 amps, a wind generator that charged at 4 amps, and of course our solar panels that were chugging out 2 amps on average. These are 24 hour figures based on our central monitor. For any long distance, need all three to get a charging system that offsets usage. We ran a frig, freezer, air conditioning, lights, all electronics, water desalinization, and radar off this system every day and never had the need to fire up the Perkins for more charging while underway.

[roland stockham]

Originally Posted by reed1v

We used an inwater prop generator while underway that charged at 10 amps, a wind generator that charged at 4 amps, and of course our solar panels that were chugging out 2 amps on average. These are 24 hour figures based on our central monitor. For any long distance, need all three to get a charging system that offsets usage. We ran a frig, freezer, air conditioning, lights, all electronics, water desalinization, and radar off this system every day and never had the need to fire up the Perkins for more charging while underway.

What size panel and where were you cruising?

[skipgundlach]

Try these folks, too...

Sungold Solar 340W SG340W-36V Solar Panel, Mono - Sungold Solar - ACOPower.com | ACOPower.com

$289...

No, I've not used them; in research for my own boat.

See also this thread:

http://www.cruisersforum.com/forums/...um+-+Emails%29

[ramblinrod]

Responses in red.

Hi All, I am not currently cruising full time but make extended trips (2-3 Months) and may not have shore-power when docked
Just looking at ordering the parts for a solar charging setup and need some advice from people who have used this stuff, it's my first system! have read all the bumph and many threads on here but if you have experience with solar could you look over the system and comment. Thanks


Congrats!

Boat. 35ft classic, Radar, small fridge and autopilot are main consumers and all lights etc are LED. Nav is by tablet and only on for coastal. From experience I use 50-75a/h per day. This may go up a bit as I have just installed a more powerful pilot but I also have a wind vane. I occasionally get up to 125 when running nav, auto pilot and radar 24-7 plus making lots of coffee!!! (the electric kettle gets used when it's iffy and I can't stay below to work the stove).


50 A-hr today when running electric (assumed) refrigeration is pretty light. Most fridges will draw 50 A-hr per day on their own. For your size of boat and amenities, I recommend planning on 100 A-hr per day.

At the moment I find that, on a long run, I don't have the engine on for long enough to fully charge the batteries so they go down to about 85% and stay there, bad for the batteries and reduces power available if it is needed.

This is concerning. If your batteries start out in the morning at 50%, and you motor till evening, with your set-up the batteries should be at 100% or darn close. Check to ensure that your regulator is sensing the battery voltage and not the diode isolator voltage.

That said, 85% SOC with an alternator is about what most shoot for (shutting down the engine when this is reached) as the acceptance rate of the batteries (standard FLA (Flooded Lead Acid) diminishes as the SOC (state of charge) increases. To charge higher requires an inordinate amount of running time.

Electrics. Externally regulated 90a alternator, 2 batt banks one about 350a/h for domestics, one 300a/h for nav and ships gear. 3 way diode to batteries. Charge acceptance with low batteries is greater than the alternator will produce (about 70a at 2000rev). I am happy to continue to use the alternator for bulk charging if needed.

My recommendation is to get rid of the diode isolator, and combine all deep cycle batteries into one bank. This helps assure that the overall battery SOC is higher and the batteries last longer, as compared to drawing down a small bank while the other bank is fully charged. When you replace the batteries, go for same make and model for all (unless you have an isolated start battery, which may be different.)

Your alternator is pretty much right-sized in my opinion (for standard FLA batteries). If your batteries are at 50% SOC or greater, they will take the full alternator output for some time, and then as they charge the acceptance rate will limit what they can take from the alternator. A larger alternator will only save you a few minutes of charge time to 80% state of charge, in practice.

What I want the solar system to do is;
1. Keep/recharge batteries when the boat is unattended.


If a 600 A-hr battery bank is at 50% SOC (300 A-hrs), meaning full consumption for 3 days with no solar charging whatsoever (unusual) a 400 W system would bring it up to full charge in 2-3 average sunlight days.

2. Reduce engine run time so that normally I will not need to run the engine either underway or at anchor.

For 100 A-hrs / day consumption, I recommend a 400W system. On an average day, this will replenish everything consumed. If you live aboard full time, I would bump this up to 600W (if you have the mounting real estate) to allow dipping into your battery capacity on cloudy days.

3. If I have used more power and need to run the engine I want to do the bulk charge in the morning from the alternator but for the solar system to then get the batteries back up to full charge during the day.


Yup, that's typically what folks want a solar charger to do.

The system I am looking at is a 245w Kyocera panel and SOLARBOOST3000i 30A 12V MPPT PV CHARGE CONTROLLER.

Questions
1 Can I hook the panel to the diode block on the alternator input, does the controller have remote batt sense or can it be adjusted to compensate to the diode voltage drop (about 0.75v)?


RTFM (Read the friggin manual). First, I assume you mean can the "CHARGE CONTROLLER" be connected to the isolator. The answer is yes, but don't. Again connect your house banks together, and connect the charge controller to the single house bank (via proper fuse.)

Most MPPT controllers will allow adjustment of the charge voltage to compensate for a diode regulator, so this is an option if the controller doesn't have (or come with) a battery voltage sensor. Just because you can, doesn't mean you should. Isolating house banks from each other does more harm than good.

2 If I get a second panel will I also need a bigger controller? What happens if the panels occasionally produce more than 30a, does it simple limit the current or will it blow the controller?

First of all, don't go with a single panel mounted athwartship. If any part of it is shaded, the output will be killed. The more discrete panels mounted athwartship, the less impact of shading one. For a 400W system, this would be 4 x 100W panels, each being about 2'W x 4'L. If your bimini is large enough to support this, you're golden.

3 In the real world sailing from Panama north to Canada what am I likely to get in A/h day from this panel?

With a 245 panel mounted athwartship (partially shaded most of the day), about 30-40 A-hrs. With a 4 x 100W panels mounted parallel to centreline, (average one panel shaded at a time), 110 A-hrs / day.

Do you think it will be big enough? I am guessing I will get about 60% rated output for 6h/day with a peak of about 90% allowing for sun angle and transmission losses, is this about right?

I make calculations based on 4 hours of 100% rated output / day avg. It works out close to what you have with your calc. IMHO, 245W in a single panel is a bad idea. 2 x 125W panels will do you much better. Still this will only generate about 80 A-hrs / day, which I suspect is under your average daily consumption, and does not allow for less than avg. sun.

4 I have seen various controllers on Ebay as direct purchases from China which would save $100-200. I have had good results buying LED lights that way but anyone used controllers from there and were there as expected?

I sell low end and high end controllers. If you are living aboard and really counting on the system, I recommend higher end. As with every country of origin, some products may be good and some not so much. You need to determine whether the price is lower because of the lower labour rate, or quality corners cut. This is compounded by the E-bay channel. A bricks and motar retailer who has been in business for 20 years, is not as likely to flog crap as a new E-bay start-up out of garage.

PS, I only sell locally, mostly what I install, so I have nothing to gain here.

5 Do people rig panels so they can be taken down for storm conditions or will they stand up to 50kn if well mounted?

Nope. The installation should withstand 50 knots, no problem. Handling the system for every afternoon thunderstorm is likely to cause more damage than it saves.

I may be able to fit a second panel if needed but getting concerned about windage and loading on the stern arch if I do. It would also be over the stern above the rudder and windvane so a bit vulnerable. Some extra windage will be good as she has a high bow that tends to blow off.

Again, I would recommend at least 2 panels, more is better. Windage really comes into play when healed. Leave a gap between panels, bigger gap is better. A flat rack is better than an arced one for windage and presentation to the sun.

The footprint of an 8' x 4' panel array (like the 400W system recommended) is smaller than the bimini on most modern 35' sailboats.

If panels are mounted a couple inches above a bimini, they don't present any signifcant windage more than the bimini itself. Mounting above the bimini, may often result in shading by the boom. Shifting the panels aft of the bimini (at least partially) may reduce shading but increase windage. Exposure to physical damage isn't really a problem, as if you run into something that close astern or abeam, you have other issues.

Regardless of mounting, the 4 x 100W System recommended, would not produce much more windage than the single 245W panel you are considering.

[/QUOTE]

Happy Sailing,
Ramblin Rod
Marine Service Provider
About Sheen Marine

[bratzcpa]

I have a 32 monohull in Florida. Last year I chose to install 3-150 watt panels and a 40 amp MPPT charge controller. very happy. I have a similar setup for electrical consumption (perhaps a bit less as I have do NOT have radar).

Also installed a Balmar SmartGauge to monitor the battery status.

I went with 3 separate panels because I could replace them individually if there were any problems. Also easier to mount than one big huge panel.

I went with an oversized charged charge controller (40 amp) so that I could add more capacity later if I feel like it. The higher level controller had more "features" then the low amp models too.

I find that in summer I have no problem - never need to run the engine. The solar panel easily keeps the house bank charged up. However, in winter, we have shorter days (so less charging hours) and sun is at a lower anger (less efficiency). If it's FULL sun all day, it keeps up with things (mostly), but usually I have to run the engine a little, or perhaps everyone other day in winter.

I bought my setup from WindyNation (Windy Nation). very pleased. I had some trouble this winter and they were able to email me some good/easy troubleshooting help. Worked great and solved my problem quickly.

Good luck - it will take some time to get it figured out and "dialed in" but once it's done, it is silent, easy, cheap and (mostly) trouble free.

[SailorGerry]

Roland - For my Jeanneau 45, I installed 2 high quality Kyocera 260 W panels with a 30 W Midnight Solar KID MPPT controller. The KID is a true marine grade controller that can be programmed for any battery chemistry. I use LiFePo4, and the system works perfectly. The panels are fixed atop the bimini, so optimal alignment is not achieved. I would add more if I had the room. In 7 months use, the highest output is ~25 amps. What's cool, is that when the boat was in the Broughton Islands last summer, I was getting 2-7 amps in the overcast and light rain! The panels meet most my daily needs while in Mexico now.
I purchased mine from Northern Arizona Wind & Sun for $275 ea last summer. Solar Electric Power Systems For On & Off Grid | Panels and More | NAWS
Shipping can be expensive for a 66"x46" fragile item, but if you have them shipped to a business address with a pallet receiving area (as I did), it's almost half the cost. My shipping was ~$170 to Washington St. Solar is the way of the future!

[BobLoucks]

Good points. The microwave was a primary consideration regarding pure sine wave vs. modified. My research shows that most appliances with a digital timer AKA Microwave go wonky with a modified wave. See http://www.xantrex.com/documents/tec...-universal.pdf
Problem is that once you need 1000-1500 watts for a microwave you have most other appliances covered.
On the Morgan 37 the boom will not be a huge issue however this should always be considered. Also want to make sure the helm can see the wind vane. We had a Bimini & Davit configuration on a friends Niagara 35 using 3 panels. It served us well on a trip from the upper Great Lakes down the coast and around Florida to Tampa.

[ramblinrod]

Originally Posted by BobLoucks

Good points. The microwave was a primary consideration regarding pure sine wave vs. modified. My research shows that most appliances with a digital timer AKA Microwave go wonky with a modified wave. See http://www.xantrex.com/documents/tec...-universal.pdf
Problem is that once you need 1000-1500 watts for a microwave you have most other appliances covered.
On the Morgan 37 the boom will not be a huge issue however this should always be considered. Also want to make sure the helm can see the wind vane. We had a Bimini & Davit configuration on a friends Niagara 35 using 3 panels. It served us well on a trip from the upper Great Lakes down the coast and around Florida to Tampa.

You mentioned about a 300W inverter.

Pure or mod, that ain't gonna run a microwave.

To be able to run most household AC appliance with resistive heating elements, you will need to have at least a 1500W (continuous) unit.

Mod sine tends to have the following issues:

1. Power supplies (e.g. laptop) run hotter.
2. GFCIs hum.
3. Some variable speed tools work fine, some need to be started on slow speed and then increased, some won't run at all.

The advantage of only 1000W is I can tell the first mate she can't run the hair dryer, curling iron, toaster oven, or water heater off of it. (Now wait a minute, that means she's gonna be unshowered, without styled hair, and serving plain bread.)

If your budget will allow, I would recommend at least 1500W pure sine. (Assuming you have the batteries and charging system to support).

This way, you can run most household appliances without any issues (and the first mate will be cleaner and prettier and you'll get hot delicious food instead of a can of cold beans.) ;-)

Just be aware that running a 1500 W appliance for 15 minutes, draws about 40 A-hr. (If the lady needs a lotta work to get pretty you need a generator!) ;-)

RamblinRod
Marine Service Provider
About Sheen Marine