Solar system???

Wow...great info. Thanks to everyone contributing to this thread.....learned a lot.

BruceK said:

If put off by Chinese manufacture, you`ll have trouble buying anything, though some will claim German design.

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The Chinese do not seem to do all that bad with their solar panels (unlike some other products). I think that at one time (and perhaps yet) they envisioned being the primary supplier of solar panels, and put a whole lot of government subsidy dollars into the production facilities, so perhaps that helped the quality.

Brand: Suggest Kyocera. The 140 watt panels may be most cost effective. But figure out what you can fit.

Also you might want to separate your load on the boat so that you can operate your refrigeration on shore power, turn off your charger and run everything else on the solar. If you still have extra power you can turn off the charger during daylight hours.

Solar panels

Here's what I managed to install it on my "Marine Trader Sundeck 36": 3 Kyocera 250W or 750 watts producing about 250 amps per day for consumption of about 200 amps per day.

Result my batteries (6x6V and 2x4D) are often fully charged. (Best efficiency for everything that has a motor like the fridge).

Total total
cost: $ 1,948.20 (May 2014).

Everything works fine while the generator is resting!

You can find a lot of information and good prices on the following sites:

AltE: Solar Panels & Solar Energy Gear | Call 877-878-4060

Solar Electric Power Systems For On & Off Grid

One other thing to add about panel selection, and how an MPPT charger opens you up to a much wider selection.

Back on the PWM description, you'll recall that all the power you get from the panel is that which is available at the battery voltage regardless of the panel's rated voltage. As a result, it only makes sense to get panels that are rated a little above the max battery voltage that you expect. For a 12V system that ends up being around 18V give or take. Anything more than that is just wasted power. Furthermore, you need to wire all your panels in parallel to maintain the 18V max voltage. When you go looking for panels, you will find a very limited selection, and the panels tend to be smaller in capacity (around 140W max), and a good bit more expensive per watt.

On the other hand, you will recall that an MPPT controller is based around a DC-DC converter, and pretty much all of them can accept an input voltage up to around 140V. So all of the sudden you can pick panels of pretty much any voltage you want, including the 250-350W panels that are out there. And you will be able to find panels that cost around $1/watt, if not less. This ends up being a huge advantage when you are trying to fill the limited space you have available for panels because you have a much wider selection of shapes and sizes to choose from. I was able to find panels that almost perfectly fill the space available on my hardtop, and probably wouldn't have even come close if I were constrained on my selection. They happen to be the same Kyoceras as Jacques.

Also, someone mentioned muticrystaline panels earlier. They tend to have the best power per square foot which is highly desirable on a boat. Avoid the flexible panels because they are much lower power per sq foot.

Peter, do you have a blog entry detailing either the system on the Nordy or the off grid system you use at home? I'm in the initial planning stage for a grid-tie system for our house.

I bought my first panels in the early 80's from Solarex. Now I have Kyocera, but I really didn't see much evolution of the panels going on until China got involved. They might not be making the truck of panels, but the march to a more efficient panel is finally got some momentum, and I'm looking at changing-out my Kyocera's for panels that are costing around a buck per watt with a MPPT charger. If they last half as long (or even less), it may be long enough to be ready for the next tech advancement, which I understand is underway. Ultimately, I want to loose my reasons for having a genset.

CPseudonym said:

Peter, do you have a blog entry detailing either the system on the Nordy or the off grid system you use at home? I'm in the initial planning stage for a grid-tie system for our house.

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A wrote a blog entry here Adventures of Tanglewood: Solar Power? when I first starting thinking seriously about solar on the Nordy. Back then I concluded I should wait before buying/building, but subsequently changed my mind. Part of the change was opportunistic. AltE Store was having a sale on the panels that fit nicely on my hardtop, and it dawned on my that I could save a bunch of $$ on shipping if I bought the panels locally (Alt E Store is local to me) and carried them out in my trailer along with all my other boat stuff.

Over the course of today I've been thinking I'll do another blog based on the stuff we've been discussing in this thread, and probably elaborate on the Nordy system, but that last part is probably pre-mature since it's still just a pile of parts in my trailer.

As for a grid tied system, I've only built one, but they are way easier than an off-grid system. No batteries, no calculations about loads, no calculations about battery size, and no calculations about recharge times and required solar capacity. And no worries about peak loads, rainy days, or other inconveniences that reality brings to your door.

Whatever power they generate comes right off the top of your power bill. The more solar, the more comes off the bill. The only trick is to not generate more with solar than your total consumption, and that's because of how net metering works.

Power that you generate reduces your retail power bill, so you are essentially getting paid full retail price for your generated power. This is true as long as in aggregate you are still buying some power from the utility. I think in most cases the aggregation happens over the course of a month, but I'm not certain.

But as soon as you become a net producer of power, you start getting paid wholesale, if at all. The details will depend on your particular state's net metering laws. But the bottom line is that the rate you get paid for power generated in excess of your own usage drops precipitously. So the best economics for you are for power generated up to, but not exceeding, your own consumption.

Let me know if you have any particular questions and I'll help if I can.

twistedtree said:

Let me know if you have any particular questions and I'll help if I can.

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Thanks, I'll shoot you a PM if anything particular comes to mind. I read your blog often and was hoping you had a detailed entry or two I missed for your off-grid system. The detail you apply to your blog makes it an entertaining( for me at least, nerds unite ) and informative read. While I believe disconnecting from the grid "may" be illegal in my area the thought of doing so intrigues me.

I'm wireless for phones, data and have shunned the business model for subscription based tv. The thought of self sufficient power supply appeals to my inner hippie

I'll be designing a passive water heating system too. We had a commercially purchased one on a previous home and our water heater rarely fired up summer or winter, regardless of demand load.

I just posted a blog entry called 'Solar 101". It's mostly a regurgitation of what we've discussed here, but includes a little background on the off-grid house system.

I think the world would be a better place if we could all find our inner hippie

Just wanted to say that this post has helped me immensely. Thanks to all for their insight, experience, and knowledge of solar. I plan on supplying most of my daily use with solar. With approx 64 sqft of surface, it should suffice. I'm not a "dooms day prepper", but do find comfort in knowing that I will always have free (except for initial cost), environmental clean power if things ever went bad (ie ZOMBIES ).

Thanks again!

Josh

Well, it seems a lot of the basics have been covered here, so I will just add our experience. We installed two 245w panels a couple of years ago and are very happy with them. We are full time cruisers and away from the docks ‘out there’ from sometime in March until the beginning of November when things turn too stormy. (Except this summer where are taking a break to help out my Wife’s folks). As such, we produce all our electrify on-board. Given the cost of diesel generation I figure our solar system will pay for its self in under 4 years. And all that time I get to listen to less generator run time!

The biggest cost and hassle was the panels themselves. Costs have dropped massively from a few years ago, easily under $1/watt these days, but this is almost exclusively with the large ‘house size’ panels. The sweet spot for them raise every year and are perhaps around 280-290w these days? But the problem with them is shipping – it can cost as much, or more, to ship a couple of panels as the panels them self. Purchasing local is the key. We talked to a local supplier who added a couple extra panels to the next pallet stack he ordered and got panels for a very reasonable price. Being in CA, you likely have many local options to pick from.

Finally, our MPPT controller has data logging capability, and I have tracked a couple of years of actual output. The following link to our blog has a year’s worth of data posted, as well as a link to a modeling process where you can predict rather closely the exact power output for any setup you will be considering. (I just could not live with 'Lots', 'All We need', 'Recharges batteries by 10am', nor 'I have no idea' that I got when asking folks for their experiences)

mv.VikingStar: A Year with Solar, or is it: “Wait until he figures out what a monumental waste of money that was”. . . . .


Good luck to you!
-al-

The KEY to solar is the reefer load.

A boat with a high efficiency reefer is not that hard to go solar.

With a crap reefer the solar/battery/inverter costs get out of sight.

FF said:

The KEY to solar is the reefer load.

A boat with a high efficiency reefer is not that hard to go solar.

With a crap reefer the solar/battery/inverter costs get out of sight.

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Agree in part. With a 110/220 volt refrigerator it would be more difficult to eliminate the use of a generator, but any reduction in use of the generator is a cost savings which may pay for the cost of the solar panels over time.

My very small Home Depot frig-freezer, small apartment sz 19"x 44" and it pulls 90watts add in inverter easily totals 96 watts / 12 = 8amps+ at 12 volts. I can run my 3 2.5 amp Engles for that. Domestics wit Danfoss are about 3 amps at 12. Just to give ya an idea. In the AM I run the generator about an hour or so to make water, coffee, heat water, but I could forgo that if I do not need water. The PO put in one hell a system. 735 w solar, 400 w wind 1125 amps battery.
I am convinced that solar is the answer for our country need for electric energy, must be, considering how hard the electric companies are fighting it.

thomasonw said:

Well, it seems a lot of the basics have been covered here, so I will just add our experience. We installed two 245w panels a couple of years ago and are very happy with them. We are full time cruisers and away from the docks ‘out there’ from sometime in March until the beginning of November when things turn too stormy. (Except this summer where are taking a break to help out my Wife’s folks). As such, we produce all our electrify on-board. Given the cost of diesel generation I figure our solar system will pay for its self in under 4 years. And all that time I get to listen to less generator run time!

The biggest cost and hassle was the panels themselves. Costs have dropped massively from a few years ago, easily under $1/watt these days, but this is almost exclusively with the large ‘house size’ panels. The sweet spot for them raise every year and are perhaps around 280-290w these days? But the problem with them is shipping – it can cost as much, or more, to ship a couple of panels as the panels them self. Purchasing local is the key. We talked to a local supplier who added a couple extra panels to the next pallet stack he ordered and got panels for a very reasonable price. Being in CA, you likely have many local options to pick from.

Finally, our MPPT controller has data logging capability, and I have tracked a couple of years of actual output. The following link to our blog has a year’s worth of data posted, as well as a link to a modeling process where you can predict rather closely the exact power output for any setup you will be considering. (I just could not live with 'Lots', 'All We need', 'Recharges batteries by 10am', nor 'I have no idea' that I got when asking folks for their experiences)

mv.VikingStar: A Year with Solar, or is it: “Wait until he figures out what a monumental waste of money that was”. . . . .


Good luck to you!
-al-

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That is great data, and extremely helpful. I didn't see it mentioned, but I assume you are 12 volts, and in the PNW are generating around 1800 watts per day during the cruising season, or about 3.5 times the total rated wattage of the panels daily. Am I calculating that correctly?

Hello,
I have been reading this thread with a lot of interest. I have been looking for Sunpower panels 327w or 345w for a while. One question I have - has anyone had any problems with solar putting a low amp charge into the batteries and causing sulfation?

HenryD said:

One question I have - has anyone had any problems with solar putting a low amp charge into the batteries and causing sulfation?

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No. I think sulfation comes from a chronic undercharged state rather than a slow rate of charge. Might be different if the rate is so low batts never get fully charged.

Being a solar virgin so to speak, can anyone give me an idea as to the average life expectancy of solar panels?

Given that most electrical equipment on boats tend to lead a tough life, especially those in salt water, will a marine environment unduly affect the operation of the panels and their connectors?

Andy G said:

Given that most electrical equipment on boats tend to lead a tough life, especially those in salt water, will a marine environment unduly affect the operation of the panels and their connectors?

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Andy

The solar panels on Bay Pelican are the one item that has not suffered from salt water corrosion. I would think the key is to minimize the electrical connections on the exterior of the boat. In my case I used an unspliced cable from the panels directly to the solar controller on the inside of the boat. This is probably standard installation technique. The panels themselves, at least those in the marine world, appear to have connection boxes which are weather resistant.

Many have warranties exceeding 20 years.

Delfin said:

That is great data, and extremely helpful. I didn't see it mentioned, but I assume you are 12 volts, and in the PNW are generating around 1800 watts per day during the cruising season, or about 3.5 times the total rated wattage of the panels daily. Am I calculating that correctly?

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Thanks, I was so frustrated by not being able to get hard data, thought might try and ease the pain for others

Yes, 12v. I pulled the Wh data as well, but have not plotted it. Will do & so post it. I decided to go the Ah way as boaters seem most comfortable with that unit of measurement, incomplete as it is.

Scanning the data, there were a lot of 2,000 - 2,500w or so days during June/July/Aug - will put up a new chart later today.

-al-

FF said:

The KEY to solar is the reefer load.

A boat with a high efficiency reefer is not that hard to go solar.

With a crap reefer the solar/battery/inverter costs get out of sight.

Click to expand...

Aside from refrigeration and freezer loads, we have been a bit surprise just how much computers can take - even our laptops. Doing a bit of work-from-the-boat, and the others face-book time we rack up a few hours a day. It can add up in Ah draw much quicker then I would have expected.

thomasonw said:

Aside from refrigeration and freezer loads, we have been a bit surprise just how much computers can take - even our laptops. Doing a bit of work-from-the-boat, and the others face-book time we rack up a few hours a day. It can add up in Ah draw much quicker then I would have expected.

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My netbook draws 11 watts, wife's 14" laptop 35 watts.

Another power hog is sat tv boxes.

Mule said:

Another power hog is sat tv boxes.

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Living at anchor I have put in an on/off switch for power to the stereo, TV and all such boxes. The phantom draw when nothing was "on" was significant.

I went back and created a chart from the Wh/day log file out of our TriStar MPPT controller. Also noted I have another Ah graph that includes about 18mo of data, a full cruising season + a major part of a 2nd one. Here are the two graphs:










Note the Ah one includes the predicted output as reference. For a bit more info on our experience with Solar panels, these graphs came from here:

mv.VikingStar: Solar


And Delfin, the average daily Wh output from our 480W (2x-240w) total of panels in 2013 was:
Apr: 1,410-Wh / day
May: 1,880-Wh / day
June: 2,194-Wh / day
July: 2,502-Wh / day
Aug: 1,695-Wh /day
Sept: 1,019-Wh / day

Refer to the above link for details on our setup.

Because we are away from the dock so much out of a year the panels are a no brainier. Doing everything again I likely would have doubled up on the panels, cut our house battery size in half - and perhaps forgo the DC generator... But the real answer comes down to individual usage patterns. For me, the best part of the above graphs is how the modeled/predicted output matched well the actual measured results. With tools out there it is easy to model any potential setup located about anywhere in the world.

-al-

thomasonw said:

I went back and created a chart from the Wh/day log file out of our TriStar MPPT controller. Also noted I have another Ah graph that includes about 18mo of data, a full cruising season + a major part of a 2nd one. Here are the two graphs:

Note the Ah one includes the predicted output as reference. For a bit more info on our experience with Solar panels, these graphs came from here:

mv.VikingStar: Solar


And Delfin, the average daily Wh output from our 480W (2x-240w) total of panels in 2013 was:
Apr: 1,410-Wh / day
May: 1,880-Wh / day
June: 2,194-Wh / day
July: 2,502-Wh / day
Aug: 1,695-Wh /day
Sept: 1,019-Wh / day

Refer to the above link for details on our setup.

Because we are away from the dock so much out of a year the panels are a no brainier. Doing everything again I likely would have doubled up on the panels, cut our house battery size in half - and perhaps forgo the DC generator... But the real answer comes down to individual usage patterns. For me, the best part of the above graphs is how the modeled/predicted output matched well the actual measured results. With tools out there it is easy to model any potential setup located about anywhere in the world.

-al-

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Again, thank you so much for objective data. This is most compelling information. We use around 5 kw per day, mostly because we run Delfin pretty much like a condo on water. No problem if we are moving, but I have to recharge after 36 hours on the hook. I am pretty sure we could fit slightly more than you have room for over our pilot house and it looks like we would potentially get half of what we use from solar, and that is nothing to sneeze at. And, if we made an effort to conserve (not our strong suit), we might be able to get closer to breakeven. The fact you are in the PNW where we are is a huge advantage in the utility of your data, so again, much appreciated.

Superb info. For a change, I'm sure glad to be in the sunny State of FL.

You are welcome for the data - I was sooo frustrated when I started things out not being able to find solid answers, I made a vow to collect real info and share it.

Now, I think the one thing that surprised me the most was how close our actuals tracked with the predicted. I went about predictions the hard way, and then found this tool: PVWatts Calculator

It is designed for land installs, but with some simple tricks can be used to product very accurate results for a marine/boat install as well. For fun, I used this tool just now - and looked at the differences between Friday Harbor up in the PNW, and Key Largo, down in the Sunshine State. Here is what I got for our 480W/12v system:



Kind of interesting to see that during the peak 'cruising' months predict more out of our Solar Panels up North then in Florida! Because the modeler uses actual data as its input (you pick a reference point to use), it can make adjustments not only for latitude, but also typical cloud cover.

I have some more details about this tool, and how to make adjustments for 'marine' use here: mv.VikingStar: Solar Panels on the Boat - Modeling and Performance

And before folks start abandoning Florida for the sunnier PNW, better remind folks about all the floating debris/logs waiting to hole your hull - Mosquitoes with first and last names, and what ever I can come up with