Solar panels

[mike]

Bri,

Thats the one good thing about the Coppercoat, nothing comes off it when you pressure wash it except the slime.

Interesting about your rules, when I owned the yard we had a slipway hoist which we used on a 1/7 gradient rented Council slipway. during the summer when there wasn't a lot of activity with lifting & washing boats the slip would grow a layer of slime, we were often asked to tow day sailers on their trailers together with the vehicle up the slipway with our 4 wheel drive tractor as they had got stuck on the slime. The end of the seson was a different matter once we started lifting boats for the winter & pressure washing them at the top of the slipway with the run-off going back into the river in a matter of a couple of days the slipway was clear of all slime; killed off by the antifouling running over it. I often wondered what environmental impact what we were doing was having on the river.

Many years ago we had a customer who died as a result of sanding antifouling paint, there was a material called Graphkiller made for racing yachts which was a graphite based material to make it soft & easy to burnish with an antifouling TBT in it, he'd sanded it & it got on his lungs causing breathing failure. We also had a customers daughter who got TBT on her skin while applying the material; she came out in big blisters & was also hospitalised.

TBT has been banned over here for around 20 years except on large commercial vessels (tankers) they found it was causing oysters to produce shell rather than muscle.

The government had inspectors going round boatyards making sure no one was using it, one of the guys use to be in the marine trade but came sensitised to TBT, all he needed to do was go near some of it & he would start to come out in red blotches - good qualification for the job!

Mike

[clonjers]

back to solar panels.

There is a short article in Ocean Navigator this month on panels.

FYI

[dolphins]

So, here is what I have decided:

I have decided that I don't want one more system on board. Solar panels are heavy. They have to be mounted. They have to be monitored (are they actually working.) And so on.

Instead, I have decided to reduce my load. I invested in Sensibulbs. I bought three reading lights and the masthead light, and a couple of courtesy lights to replace my existing bulb systems.

This will reduce my current load to one tenth. Yes, I am spending close to a boat unit, but from all my research, I have found that the bulbs will need less care and attention and replacement than the solar panels.

I like that idea. Now, remains to be seen if I have reduced enough.

-Mathias

[rick_bradshaw]

We've also gone to LEDs to cut the power usage. They help but still cost some power. The power "sucker" is the refrigerater. Unless you have an ice box or plan to not have refrigetation of any kind, you will be very surprised at how fast the batteries go down.

Mike,

How many years do you have on the copper bottom? How did those barnacles test out; on just the slime or firmly attached? We're thinking of doing that in when we get to Florida before, hopefully, going to the Med, etc. on that side of the world.

Right now we have just delayed ourselves by about a year due to this El Nino year and not wanting to get down in the really crazy weather with increased lightning during the "wrong" time of the year.

[Great_Aardvark]

In restoring Shearwater I am replacing all of my lights with LED this includes both navigation and interior. Also everything on board is built to run on 12 volts, this includes the TV, this way I do not lose any energy converting from 120 to 12 volt using a converter. Also when you have most 120 volt electronic devices such as TV you are already converting the 120 to 12 volt (or lower) inside the device since most of these devices run internally on DC. The two big energy users will be the reefer and my diesel heater. I intend to add insulation to the reefer to try and get the cycle time down. Without these two I believe I will use only 528 watt hours a day. This include using multiple light and fans for multiple hours and also the GPS and autopilot for 24 hours a day. With the heater and reefer it jumps to 1790 watt hours a day. I may replace this old reefer with a new one if I am going to do some serious long distance sailing. Even with the big number I could get a complete change in about 4.48 hour with a wind generator and at least 6 knots of wind. Without the LEDs the power requirements would most likely be at least doubled. Example is the dome lights are LED = 2.16 watts while the incandescent = 15 watts.

Tony

[rick_bradshaw]

Tony,

Those numbers sure sound great. You must be in a cooler area with nice (for these purposes) cool water and intend to stay there.

We did much the same as you. Converted to LEDs inside and out. Everything runs on DC except for the computers, satellite radio, and coffee grinder. These (except for the coffee grinder) are not on when at anchor much and that is to send/receive email via HAM. Our inverter is only 700 so everything is certainly low draw.

Our Spectra water maker is the small one and we can go many days before we have to make water but then it is most of the day to refill. Or, we can run a few hours about every 3 or 4 days and take up a little more power on those days. While it is the "Ventura 150" model, it still takes considerable power, relatively speaking to use. You may not have that problem/convenience.

We added R6.5 per inch foil wrapped "bricks" to the inside of our refr. 2" outside and the after end and 1" to the inside and forward end. Built up the bottom until it is flat (about 2" or so). Changed to a smaller evaporator due to space. Put a "seperator" partitition just behind the evaporator (about 1" behind) and under (about 1" under). Added a hose with a muffin fan to draw cold air from the evaporator area and distribute it to the refrigerator side. Lost most use of the front door due to insulation added. We have shaded the side of the hull where the refr is located with a sunbrella bag with about 3 layers of that quilted stuff that is foil backed both sides inside that. (If given the $ and time we would rather have removed the entire refr and started to build up from the hull. However, we read the article on HCOA and decided we didn't have the $ or time.)

We have 2, 85W panels that on a good day with monitoring and moving the panels, we can get just over 11A (combined through the Solar Boost 2000E controller) and an Air-X Marine wind gen (that I have witnessed, via dedicated amp meter, 30A come through before it shut itself off) that we can get an average of about 4 to 8A out of it in 10 to 15 knots or so of wind. Our battery bank is 440AH. With both these power generating methods on, we can go (so far) maybe 5 days without turning on the engine to generate power. Our alternator is a Balmar high output 70. At that point, we are way down and it takes a few hours to build it back. BTW, we don't have a diesel or any other kind of heater to add heat to our boat.

I think we have done just about everything we can do to become more efficient. Still, we go in the "hole" every day if we have anything on. At anchor we run our anchor light. Even if we went to sleep and got up with the sun, the refr (A/B super cold air cooled) would take the great majority of the amps especially when the air temp is nearing 100 degrees (F) or more and the water temp is closing in on the 90 degree (F) number. It runs up to about 75 or 80 percent of the time. Gets less use when the water/air temps go down.

Your power generation methods don't do a consistent number of amps. The wind gen ability goes up and down depending on the wind or lack of it. The solar panels go up and down depending on the angle of the sun (when it is shining) to the solar panels and if the panels are shaded by something or not. (Note that in the warmer weather you will want a shade over the entire boat or most of it to keep the heat down below decks and that can shade the panels some of the time.)

If you're heading into warmer water, take note that things will run longer and take more power. If you have to choose between solar and wind, keep in mind that the wind is intermittent and the sun, when it shines, is more consistent. We need (we think) to add solar capacity in the form of maybe 135W panels instead of the 85's. We've done all else that we can think of and we are in the warmer water so we speak from direct experience.

My suggestion is to rethink and recalculate. What if .... Your numbers are great but from our perspective they seem much too small from what we are experiencing.

When you are out cruising in warmer climes (if that is your intention) it is more difficult to make changes in whatever port you are in, in a country that you are not familiar with and that might not have any of the familiar stores or even similar stores and you have to "make do" with what you can find not what you want. Also, prices might well be considerably higher if you find what you need or can use and you may well spend several days looking for that.

Things are different out here but that's what makes it so attractive for those of us out here.

[Great_Aardvark]

Rick,
This is good info. It is good to get real facts instead of calculating from the specs. The reefer mods help me understand better about the impact of insulating. My thoughts regarding the solar panels are to go with the highest output they make. Right now you can get one over 200 watts. I live in North Carolina so I am for sure in a hot area. But I grew up just south of Miami and we had no air conditioning just fans. I learned how to keep comfortable with just fans. Our last house while we had air we rarely used it because we had a attic fan and would cool the house by opening certain widows (on the shady side of the house) and stayed very comfortable. Your right about deck canvas and I have had this made up for each of my boats. Last summer when I got the boat we had a long really hot spell but if there was usually a breeze and the HC 33 stay about 5 to 10 degrees cooler than the outside. I think this is due to the ceiling arrangement which insulates the boat. When the breeze stopped it got hot though. I think when I setup the deck canvas and get the fans going it will be fine. I am going to research for a better reefer unit and will let you know what I find.

Tony

[rick_bradshaw]

Tony,

200W? We have Kyocera 85's and I thought that 135's were the largest yet for marine application. I checked Northern Arizona Wind & Sun and they have 230W panels but they are huge:

Length 65.94 in (1675 mm)
Width 39.41 in (1001 mm)
Height 1.34 in (34 mm)
Frame Aluminum
Weight 48.5 lbs (22 kg)

This year they are priced in the $5-600 USD range this year (their anniversary) and you need special controllers for them to work properly.

Hanging 50 lbs (or 50 Lbs x 2) seems like a lot. I think what is happening is that as the technology gets better the wattage goes up but it seems like the overall size and weight goes way up too. To put a pair of these on a 33T would almost require an arch and having those panels mounted relatively high. Their weight in addition to the weight of the arch must be considerable and not down low where weight needs to be. That and the weight located in the ends means more "hobby horsing" or so it would seem to me.

I'd sure like to know how you would mount them. Always looking for a better solution while I can, maybe, make changes.

[Great_Aardvark]

I noticed the size but thought all panels were roughly the same size so I guess I need to check all of the specs. One of my thoughts is to mount a panel on top of the sea hood. Right now I have not yet started to work up how to generate power I have just done cursory looks. I believe tha a combo of wind and solar is the approach I will research.

Tony

[rick_bradshaw]

Tony,

Since you are in the planning and prep stages, I think you have the right idea about going solar and wind. Here are some things I would suggest that you think about seriously before doing much else in the power realm.

1. Decide if you want to add an arch or not. Sounds bad for these boats but several have them. "Tender Spirit" now in NZ has one that I really like (we don't have one). It nearly disappears when you look at the boat. It's there and you see it but it doesn't dominate the appearance. Custom designed in Port Townsend, WA. "Prisim" has a "DIY" version using off the shelf parts that works for them and is a testiment to the fact that you really don't need to have a huge thing that cost huge amounts of cash to have something work. It also doesn't dominate.

2. Decide on how much power production you need and then decide where to put them. If you have an arch, some of that problem can already be solved. If not you need to put them where they will not get in the way of such things as a BBQ and maybe a dedicated LPG tank for that (ours is same size as the others so are interchangeable), GPS installation, lifting davit for the outboard and the outboard itself, the main sheet and how it goes out over the side, anything that might be a problem in the future. Write it down. Draw it out. Really check it out and then sleep on it.

3. I've seen several boats with 2 wind gens. these have been long distance boats that have needed them either operating together or alternating or as a spare.

4. Spray hood solar panel attachments are seen but they can get in the way (you don't want them scratched/broken), are generally mounted so that they cannot move with the sun, and aren't as productive as they might be in other positions.

Good luck with your issues. Think several times. Measure even more times. Draw it out all the time. Check it. Check it. Check it.... All that before you do it. I've had to change things after doing them and wishing that I had thought, measured, pictured, and checked it just one more time. There have been a lot of literal blood, sweat, and tears here but it is worth it.

[Great_Aardvark]

Rick,
Thanks for the info. I agree to measure repeatedly (the old saying measure twice cut once). I will most like build a complete model on the computer when I am ready using Excel to be sure on the values. I really do not want a arch so the dual wind generator sounds good I had not thought of that. I will also have some honking big batteries to try and go as long as possible without charging. If I can offset say 80 to 90 percent of my daily usage with external generation then I might go a week before I have drained the batteries enough to need to run the motor. Having 110 to 120 percent of charging to usage is even better.

Tony

[bruadair]

Up until last December we have been cruising with two Kyrocera 120w solar panels and a Fourwinds II wind generator. Most of our interior lights are the Sensibulb Leds (didn't convert the lights that we don't use often), our anchor and navigation lights are USCG approved LEDs and only a few small items are ac only. For the computers, my electric shaver and AA battery charger we use small 175w inverters rather than our less efficient 1500w Freedom inverter. Our 12vdc refrigerator used to draw up to 100 amps per day but after finding numerous large voids in the refrigerator's insulation and filling it in we're down to 50 to 60 amps per day, in the tropics. We use a 10" portable dvd player to watch movies, it only draws 1.5 amps. Our 15" flat screen draws 4amps. David's 15" laptop draws about 5 amps and my 10" netbook only draws 2 so we use mine most of the time when doing emails and stuff.

This past December we added two more Kyrocera solar panels, each are 130 watts giving us a total of 500 watts. A lot!! The two 120s are mounted on our arch and the two 130s are mounted on top of the dodger. We haven't had any issues with the two above the dodger being in the way even with the boom. To minimize shading we push the boom out and secure it with vang to the toe rail, hasn't been out way out to the side like that.

The 500 watts of solar down here in Panama, on a fully sunny day, generates 140 to 150 amps per day, the most being 156. With some clouds we're down to about 120 amps per day. Our normal daily usage including lights, refrigerator, computers and watching movies is about 120 amps per day so most days the solar keeps us covered. Now add our wind generator which will produce about 75 to 100 amps per day in 15-20 knot trade winds and we have much more than we need. Normally with our set up we can run everything, including our water maker and still have full batteries. With excellent sun we usually put in 28 to 31 amps per hour for a couple hours, it's like running a battery charger!

But when the clouds roll in or the wind goes away then we're in a position where we use more than we generator which means we'll have to run our Honda generator every once in a while.

Some important things to know about solar panels. Panels can be wired in series for 24, 36, 48 or more volts and stepped back down to 12vdc with an MPPT controller such as the Outback MX60 that we have. By wiring in series one can use much smaller wires to the regulator which makes it easier to run wires, in our case through the arch. Our four panels are wired in series and the input to the regulator is usually about 70 volts and around 6 amps, out of the regulator during this peak is about 13.1 to 14.1 volts, 25 to 30 amps (math is a rough estimate). Using this type of regulator one can also use larger panels, we know boats here that have 300 watt solar panels that are stepped down to 12vdc by a good MPPT regulator. Be aware though that not all MPPT regulators will step down in voltage and those that do have may have limitations so be sure to read the specs.

Also important to note is that solar panel output ratings influenced based on specific temperature ratings. The colder the panel the better the output, the hotter the panel the more reduced the panel, up to 25% reduction in the tropics so be sure to plan for that. For example the Kyrocera has a reduced rating of only 87 watts when the temperature of the panel is only 116 degrees f. That's a 25% decrease in output. 116 degrees sounds like a lot but have you felt how hot a dark solar panel gets sitting in the sun all day? While our set up is rated at 500 watts we usually only see about 380 watts, which is close to Kyrocera's specs.

In regards to MPPT solar controllers that advertise "up to" 30% increase output it is important to note that MPPT regulators are also temperature sensitive. The colder the climate the higher the gain. In the tropics one should expect to see a minimal increase in output, maybe just a few percent, more on cloudy days.

I think that both solar panels and wind generators have a good place on a boat if there is room but my preference is for solar. It's nice to be able to sit at anchor and run everything we need and want to run and not worry about how many amps we're using. Oh, and just to give you an idea of pricing on the Kyrocera 130 watt panels; In Colombia the best price for one panel is about $1150, in Panama the best price we found (and paid) was $750 each. I know they're a lot less expensive back in the states.

Here's a rough breakdown of our daily amperage use on Bruadair;

Refrigerator 55 (50 to 60
VHF on 24/7 7
Anchor light 5
cabin lights 3
Fans 15 (3 fans running 24/7)
Portable DVD 6 (3-6 amps per day)
Laptops(s) 15 (10 to 20 amps per day)
Watermaker 24 (average of 3 hours per day)
Misc 5

Total 135 (we don't run the computers or water maker every day so it's usually we're usually around the 120 amp range)

[mimoza]

What a great summary! Great pointer on the wiring in series, and some good tips on the regulator, too. I'm going to bookmark this post in anticipation of the "great adventure."

Thanks!

[sv_bruadair]

Mimoza,

Glad you found some of the information useful. There are a few MPPT type controllers but I personally thing the Outback MX60 is more flexible than the others. You can input as much as much as 800 watts or 120 vdc for a 12vdc system so it leaves plenty of room for adding onto. It can also be programed for 12, 24, 36 and 48v battery banks. Many other MPPT controllers will only accept up to 24vdc input which in my case I would have had to wire two sets of panels in parallel then the two sets in series.

The manual for the Outback states that it will increase output up to 30% when the temperature is -45f, for the tropics it suggests an increase of up to 6%. The Outback also has large terminals for large wires which is nice. The front panel displays input and output voltage and amps as well as accumulated amp hours for the day, and a history of daily accumulated amp hours for the past 60 days. Anyway, that's my plug for the Outback, I really like it.

Glad you found the information useful.

[markfnovak]