Time to Add Solar--Vendor/Brand Suggestions.

Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
The time has come to get serious about adding solar power to Second Star.

The basics:
House battery bank: 4 6v Deka GC ~ 450 ah
Charger: ProNautic 1250P
Alternator: Externally regulated CMI 90 Amp alternator

While on anchor on Lake Ontario we use around 75 ah per 24 hours. The big draw is refrigeration at about 60 ah a day depending on the weather. We're pretty frugal with energy, mostly LED bulbs, turn the VHF off when, occasional use of the stereo, etc.

If we can keep our bodies and minds intact, next spring we are planning to sail out the St Lawrence and down the east coast. Adding solar will make us less dependent on marinas and motoring for charging.

The rough plan is to add 2 ~140 watt panels connected to 2 Victron suitably sized controllers. That should provide about 60 ah a day on average (23 amps x 3 good sun hours).

There is a bewildering supply of vendors and brands of solar panels. In order to narrow my search I would appreciate suggestions as to brands and vendors to review and to avoid. The budget is not limitless, however, we will pay extra to get better quality, performance, and reliability. Local (Central NY) vendors are not an option as there aren't any. Vendors in Eastern Ontario Canada might be an option.

Suggestions?

Thanks.
 
Feb 6, 1998
11,665
Canadian Sailcraft 36T Casco Bay, ME
Dave,

If you stick with panels from legit solar vendors such as AltE, eMarine, Coastal Climate Control, Wholesale Solar etc. you will get decent quality panels panels using top quality cells. Avoid resellers of cheap Chinese stuff such as Renogy, Amazon, eBay etc... Kyocera has unfortunately pulled out of the US market as they refused to cut quality in order to compete with the junk that is currently being foisted upon the US consumers.

If you want the most wattage in the smallest foot-print, mono-crystalline is your best bet. Perhaps the most efficient you can buy are the Solara Rigid Ultra line from Coastal Climate Control. These are very, very good quality German made panels using SunPower's® top grade cells. (You can't really buy actual SunPower® panels for marine use). The Solara Ultra Rigid line are the only ones I know of licensed to use the top grade SunPower® cells in a rigid marine grade panel.. Not cheap at all, you're paying for that 22.5% efficiency, but very good quality. You get a 150W in a panel that measure just 22" X 59".
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
Thanks RC.

Do you know of a source in Ontario Canada for the Solara Panels? With the 30% tariff on imported panels it would be cheaper for me to sail or drive to Canada and bring them back. I can bring back $800 of goods duty free if I stay 48 hours. That would be a about a $700 savings.
 
Dec 28, 2015
1,837
Laser, Hunter H30 Cherubini Tacoma
A option would be to buy cheaper with comparable efficiency at the fraction of the cost and replace as needed. Assuming my Renogy are almost the same efficiency (I have no way to argue this) you could replace them every other year for several years and still come out ahead. But in all likely hood you would get alot more life span out of them. I built covers for mine while in the slip for longevity reasons.
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
A option would be to buy cheaper with comparable efficiency at the fraction of the cost and replace as needed. Assuming my Renogy are almost the same efficiency (I have no way to argue this) you could replace them every other year for several years and still come out ahead. But in all likely hood you would get alot more life span out of them. I built covers for mine while in the slip for longevity reasons.
That is certainly an option. With the current tariffs, the panel is about 20% of the cost of a comparable Solara panel, without the tariff it is only about a ⅓ the cost. One big difference between the Renogy and the Solara is the number of cells. The 150 watt Solara has 44 cells and the 160 watt Renogy only has 32 cells. It is my understanding that more cells are better for marine use because the panel is less susceptible to partial shading which can be an issue because of the mast and rigging. The Solara is also a pound lighter.

When there is a large price difference, such the Renogy and Solara difference, I am always suspect. Some of the cost difference is no doubt due to labor costs, but where are they cutting corners to keep the cost down? Or is there a government subsidy for the manufacturer, which would be an unfair trade policy.

What frosts me is the high tariff. It is simply an unnecessary and hidden tax on us delivered under the guise of making trade fairer. But don't get me started because the bots will get me for talking politics. :(

I sail to Ontario every summer and only live about 90 minutes from the border by car. A weekend trip to Kingston to come back with a couple of panels would be easy and fun. :)
 
May 7, 2012
1,338
Hunter e33 Maple Bay, BC
Dave, I have dealt with Jeff Cote out of Pacific Yacht Systems in Vancouver, BC for many years. I highly recommend him to anyone that requires marine systems work. Anyway, Jeff sells panels from a number of leading manufacturers including Solbian, Gioco and Solara. You maybe surprised at the cost savings, even after adding in shipping, when you account for not only tariffs but the strong US dollar (or vice versa the weak Canadian $$).
Jeff is very responsive so give him a short email or quick phone call. It may be well worth your time. If nothing else his website is a valuable source of info.
https://www.pysystems.ca/

I also see that Dave at Marine Outfitters in Kingston, ON sells Victron solar panels. This would be within your sailing area. I have no knowledge of the quality of their panels but in general Victron is well respected. I have had Dave source items that he does not list on his website and he has come through everytime.
https://www.marineoutfitters.ca
 

Johnb

.
Jan 22, 2008
1,419
Hunter 37-cutter Richmond CA
I have a 180 watt Grape Solar mono-crystalline installed and am pretty impressed. In the pouring rain in February at approximately 38 degree North it will have delivered 5 to 10 ampere-hours by 10:30 a.m. sun time to make up self discharge and minor lighting use. In March it can deliver in excess of 6 amps for about 7 hours per day (into the batteries via a MPPT controller) and about 9 amps for the middle 2 hours.
Purchased from Home Depot for $230.
I invested in a 40 amp MPPT controller. To increase energy delivery I will parallel the panels into the controller. This arrangement is less susceptible to shading than placing the panels in series because if one of them is shaded the other can still deliver.
I disagree with the statement that more cells will be less susceptible to shading than fewer cells. Unless the panel has been split into 2 parallel sections, shading any one or more cells in the series will bring down the whole panel.
On my boat the biggest problem was quality space to mount the panels without any shading, interfering with the Hydrovane, not being in of the orbit of the boom etc. My final plan is to have just the one panel permanently mounted and deploy additional flexible panels when at anchor.
The inefficiencies from imperfect matching are minor and can be easily compensated by more and bigger panels. For this reason I am going to feed them into one MPPT controller.
Because the controller requires the panel to be disconnected before disconnecting from the batteries I installed a swith in the lead from panel to controller.
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
Contacted Solara and they don't have a Canadian Distributor, so the trip to Kingston is off the table.

On to plan B.

disagree with the statement that more cells will be less susceptible to shading than fewer cells. Unless the panel has been split into 2 parallel sections, shading any one or more cells in the series will bring down the whole panel.
Higher quality panels will have a series parallel arrangement of the individual PV cells with diodes to mitigate against power loss and over heating. The smaller PV cells allow for more strings of PV cells, for example if a panel has 32 cells it could be arranged in 4 strings of 8 cells. If a panel has 40 cells, it could be arranged in 5 strings of 8 cells. In the first case each string consumes 25% of the panel area, in the second only 20% of the panel area. The shade has a smaller target with the smaller cells. With a smaller target the panel is less susceptible to shade.

Here's one article on the subject. https://blog.aurorasolar.com/shading-losses-for-pv-systems-and-techniques-to-mitigate-them/
 
Dec 28, 2015
1,837
Laser, Hunter H30 Cherubini Tacoma
Contacted Solara and they don't have a Canadian Distributor, so the trip to Kingston is off the table.

On to plan B.



Higher quality panels will have a series parallel arrangement of the individual PV cells with diodes to mitigate against power loss and over heating. The smaller PV cells allow for more strings of PV cells, for example if a panel has 32 cells it could be arranged in 4 strings of 8 cells. If a panel has 40 cells, it could be arranged in 5 strings of 8 cells. In the first case each string consumes 25% of the panel area, in the second only 20% of the panel area. The shade has a smaller target with the smaller cells. With a smaller target the panel is less susceptible to shade.

Here's one article on the subject. https://blog.aurorasolar.com/shading-losses-for-pv-systems-and-techniques-to-mitigate-them/
I thought I read somewhere when I added my system that all the added diodes like described dramatically decreased the benifits due to their parasitic power consumption
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
I thought I read somewhere when I added my system that all the added diodes like described dramatically decreased the benifits due to their parasitic power consumption
There are always trade offs. I'm still learning about this. The link above suggested the diodes were only placed between strings of cells, so there would only be 3 diodes in the whole panel. The downside to diodes seems to be a slight voltage drop between strings in full sunlight and protection against shading taking down the whole panel.
 

walt

.
Jun 1, 2007
3,511
Macgregor 26S Hobie TI Ridgway Colorado
regarding diodes and serial or parallel..

Silicon PV individual cells will create a voltage of about .51 volts open circuit and .46 volts under load. This is temperature dependent). Here is a link http://www.alternative-energy-tutorials.com/energy-articles/how-many-solar-cells-do-i-need.html

The smaller panels we consider here are 32, 36 or 48 cells. You can find the panels peak power voltage by multiplying the number of cells by .46 volts and for 32, 36, 48 cells, that would be 14.72V, 16.56V and 22V. So pretty much any of these smaller "12V" panels we typically use will all be serial cells. The bypass diodes mentioned are normally reverse biased if the panel is in full sunlight and have a really tiny parasitic current draw and dont affect the panel efficiency. Parasitic current in the reverse biased bypass diode might be millions of times smaller than the panel output current. Curious if there is a link to where someone said the bypass diodes reduce efficiency?

Remember with series, you force the current to be the same in every cell. So if a cell gets shaded, its current can drop and the whole panel drops.

Typical panels might have three sections that have the bypass diodes. So in theory, if a section has reduced output, that section can be bypassed with the diode. That bypassed section will now have the voltage drop of the diode and you still get the full current from the other two operation sections.

That is in theory.. reality tends to be a little different.

Check the spec on your MPPT charge controller and they pretty much always specify that the panel operating voltage needs to be a little higher than the battery voltage by a volt or two (or sometimes more). Now consider a 36 cell panel that has a full output voltage of 16.56 volts. If I get shading and take out one section of three, the new panel voltage would be 2/3 of 16.56 minus the diode drop of maybe .4 volts. So the panel with 1 section bypassed would have an output voltage of 10.6 volts. I am not aware of any MPPT controller typical of what gets used that will convert with a voltage that is well under a typical battery voltage. So.. in general and with our application, those bypass diodes dont do much.

If you were to series two panels (where you force both panels to have the same current), you could actually have a bypassed section of one panel and get 5/6 of the total power from the two panels and still have plenty of voltage for the MPPT controller to operate. However this also has a problem caused by the typical MPPT controllers we use and that is that the two series panels often have TWO different maximum power points when one panel has partial shade. Most controllers will NOT find the actual maximum power point because the only way to do this is to sweep the operating voltage periodically over a large voltage range. Most controllers only search in a narrow voltage range around the previous max power voltage so get stuck on voltage that is a local maximum power but is not the best actual maximum power voltage.

If you parallel two panels, remember that the voltage is forced to be the same on both panels. If one panel gets shaded, the MPPT controller still finds the max power voltage of the non shaded panel. The shaded panel is forced to operate at this same voltage so will have a much reduced current. But.. with parallel, the currents still add so you still get something from the shaded panel.
 
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Aug 22, 2017
1,609
Hunter 26.5 West Palm Beach
I thought I read somewhere when I added my system that all the added diodes like described dramatically decreased the benifits due to their parasitic power consumption
Yea, diodes. There seems to be a lot of misapplied information floating around about them & how they affect solar controllers. My current understanding, is that the amount of effect a diode has on the efficiency of the system is highly dependent on the particular controller you have & also somewhat dependent on other factors.

A diode is basically a check valve for electricity. It lets current flow in one direction, but not the other (ignoring minuscule leakage current). Your typical diode will present a 0.7vdc voltage drop when it is conducting current. Specialty diodes, called Schottky diodes, also exist & are sometimes used in solar systems because they have a lower voltage drop. I don't like to use them because of leakage & reliability issues that they sometimes present.

Controllers vary quite a bit these days. A few months ago, I was embarrassed to find that I was spewing out of date information because controllers had progressed so far so fast. I may still be a little out of date now.

Most controllers, that I am aware of, basically fall into one of two broad categories. The first category, is the older style "regulating" controllers. The second category is MPPT controllers. The regulating controllers, just fail to pass over-voltage & usually don't do much else. The MPPT controllers typically do a lot more. Some of them have sophisticated pulse charging features. Many of them have internal DC to DC converters that can put out a higher voltage than they take in. Hence, if a panel is putting out 10vdc, some controllers will still be able to turn that power into something that can charge a 12vdc battery. You really need to read up on the features of the individual controller that you have. There are just too many variations out there these days to cover, or even know about.

When panels put out 20-30vdc, nobody is really going to see any big difference if a 0.7vdc drop is added by a diode. If a panel is putting out 14vdc & you have 3 diodes in series, giving a (3 x 0.7 =) 2.1vdc drop, then your 12 vdc battery is not going to get much of a charge if you have a regulating style controller. An MPPT controller may still be able to harvest that power & stuff it into the battery.

If your controller does not have internal reverse current blocking & you don't add diodes, the panels may actually consume power from the batteries when it is dark out. Also, if one panel is badly shaded & it is in parallel with another panel that is producing current, the shaded panel may draw current from the producing panel if there are no blocking diodes present.

For the sake of brevity, I have left out a lot of details. This is just to give you an idea of how the different components might work together in a particular arrangement. There are a lot of variations out there. Even deciding if putting two panels in series or parallel is better, can depend on a lot of things.

Edit:
I just read Walt's post. I had only considered blocking diodes. I had not considered bypass diodes. That concept adds another layer of complication to potential system layouts.
 
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Johnb

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Jan 22, 2008
1,419
Hunter 37-cutter Richmond CA
Much to my amazement, I am seeing the voltage come up to as much as 14 volts before sunrise. Yes - just from the light scattered by the atmosphere. Of course is no significant energy delivered, just a few (< 10 mA) out of the panel. By the time the sun is up to about 10 degrees elevation the panel voltage has risen above the normal MPPT voltage.

What does this tell us? If you have two panels in parallel, even if one of them is shaded, its output voltage will probably be higher than the MPPT point of the one that is contributing. During the significant, energy delivering part of the day, even without diode separation, it is unlikely that a shaded panel, in parallel with an unshaded would absorb much current, if they are anywhere near similar. With diode separation it is a non issue.

One other thing, shading does not occur in some specific well ordered way where only cells in one section of a panel will be affected, it will be randomly across the whole panel. Assume therefore that shading kills a panel, end of story.

Unless you have got lots of space you are just about as well off to have one panel, the biggest you can accommodate, in a prime location where it will almost never be shaded and can be in use at all times, than two panels where one of them will be shaded most of the time.

As another issue, the frame to put the panels on cost about 5 times the per panel cost.
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
Thank you to everyone who took the time to respond. I appreciate the comments and various insights

Yesterday I pulled the trigger on the major components, PV panels and controllers; and ordered 2 Victron SmartSolar 75/15 controllers and 2 150 watt Solara Ultra Glass panels. Read on if you are interested in my thinking about these choices.

The controller choice was pretty much a no brainer. Victron makes a good product at a fair price and with built in Bluetooth I can monitor the output and manage the controller on my phone or tablet instead of hanging upside down in some cramped corner of the boat. Big plus there, no boat yoga. At MS's suggestion I purchased them on Amazon here. The price was a few dollars less than I had seen elsewhere with an additional 5% off because I used my Amazon Prime CC.

The bigger more difficult decision was on the panels. The ideal panel would be about 140 watts, suitable for marine use, and US made. The US made part was the first issue. It seems that most if not all of the US made panels are made for permanent ground or roof installation. That means they are large 300 watts or larger with frames designed to be fully supported on substantial racks. These might have worked if I was going to build a large arch that could fully support them. I wasn't going that route.

Next criteria was marine rated, most panels do not have a specific warranty for marine use, Solara has a 5 year warranty for marine use. That's a big, but expensive plus.

Another concern was efficiency. The average efficiency ratings seem to run in the 15-17% range, Solara has a 21% efficiency rating. The greater efficiency means a smaller, lighter panel can produce the same amount of power as a larger heavier panel; smaller footprint, lighter weight, another plus for Solara. I found one comparable panel that was 3 inches wider and 5 lbs heavier for about the same output. The plan is to mount them on a frame above the Bimini, so weight matters.

The Sunpower PV cells in the Solara are also less susceptible to partial shading and produce more power at lower light levels than most other PV cells which contribute to the overall efficiency.

Since the Solara was designed for marine use, the panel is constructed of heavier gauge aluminum frames and according to the marketing pitch, the overall construction is better able to withstand the movement and forces to which the panel would be subjected. This means they are less likely to be damaged from boat movement and if they are, there is a 5 year warranty.

Finally, there is 30% Federal Income Tax credit for solar installations on primary or secondary (boat) residences. That moves the price of the Solara from completely beyond our means to just beyond our means. (And it would have within our means if it wasn't for the $150 per panel tariff tax I had to pay. Don't get me started on tariffs!)

So, the Solara panels won; smaller, lighter, higher efficiency, marine warranty, and designed for marine use. And they come in a cool all black color. :waycool:

We bought the panels from Coastal Climate Control in Bowie, MD. Nice folks and the shipping costs ended up being about half of what I expected. FedEx delivers them Thursday.
 
Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
I have had Dave source items that he does not list on his website and he has come through everytime.
https://www.marineoutfitters.ca
Hello Below is right. He turned me on to Dave last year when I absolutely needed a new lens for my Beckson port. It was broken and the rainy season was upon us. I learned that Dave sells Beckson parts and he was competitive with pricing, comparing from Pompanette & customs duties, right on the money, so to speak. Very nice folks to work with. The lens was perfect, but they sent me wrong trim ring, I let them know by email, they sent me a free shipping label and then delivered the right part almost immediately. From across the country! Couldn't ask for more.