Power: Solar, wind, lights, towed....???

[Captain Smollett]

Ok, So the question that came to mind after tinkering around on "zen" yesterday. Sea-generator: How is that better than just a plain old windvane? more volts/watts?
Someone said something about a sea-generator that could covert to a windvane while at the marina, ok, why not have it all the time then. Again is it a matter of output?

For the towed gen to work the boat must be moving through the water.  This makes it next to useless at anchor/dock.  If you have some pretty serious tidal current, you COULD use it, but deployment would be a hassel (you'd have to retrieve and reset each time the current reverses).  So, the wind gen is better when the boat is still.

A wind gen will certainly work at sea, also.  The towed gen shines for downwind passage making.  If you take a look

here

you can see the charging curves for the Aquair 100 in both towed and wind turbine configurations.  From that page:

WATER DRIVE VERSUS WIND DRIVE
Sailing downwind at 6 knots, the Aquair 100 Water Drive generates approx. 5 amps continuous charge. To obtain 5 amps of generation from the wind driven version while underway, the wind speed required is typically 30 knots (24 knots plus 6 knots boat speed).

This 5 amps x 24 hour = 120 amp-hours per day for a long downwind passage.  That's pretty hefty.

Contrast that with a 50 W solar panel.  Many recommend only figuring 3-4 hours per day of peak charging with a solar panel, so that gets 16 amp-hours (for a 12 V system).   

The beauty of the dual use system in my mind is that you can have the best of both worlds; towed when it is best, wind when it is best.

[Skipper Dave]

Zen,

I'm with Jack in that I tow a little 1000w Honda generator.  It uses very little fuel which I also keep in the dinghy.  When we are the only ones in an anchorage I give it a push and its nice an quiet down below.  Other times respect the generator off time rule.  It has come in handy a couple of times when I forgot to switch over the perko and woke up to not enough juice to start the engine.  A 1K generator will run our T.V./VCR, Inside Lights, Microwave and a small heater.  The heater and microwave cannot be running at the same time. Keep in mind we don't travel more than a couple hundred miles and at the most six, seven days per outing.

---------------------------------------------------------

This morning it looked so nice out I thought I'd leave it out.

S/V "Tina Marie" Cal 2-27 (Featured Boat Lats & Atts Oct. 05)

[Jack Tar]

Hey you guys ever heard of Ham Radio. Yes computer data can be sent via this method. The data is converted back and forth at each end. I read a little about it but not having a requirement havent checked it out.

You can also go $atilite.

Zen on the house batt I run cabin lights, Water pump, computor, CD/radio. I just watch my consumption of power. It would be nice to if you had a state of charge monitor for the system.

[Captain Smollett]

It would be nice to if you had a state of charge monitor for the system.

Ferris Power Products sells several system monitors, but they can be a bit pricey.

For a single bank, the Link 10 ($199 in my 2001 catalog) displays:

• DC amps currently being used
• DC Volts of the batts
• Amp-hours removed from batts
• Time until batt is discharged (assuming the present current draw I'm sure)

The Link 20 is the same for two banks ($310 in 2001 catalog).

They also have a Multi-Battery Condition Monitor, $69 in 2001, that gives analog display for up to 3 banks.

Besides that, there are charts that show pole voltages for different charge states, but I think these are unreliable and require a pretty precise volt meter (digital to 2 or three decimal places, iirc).

Finally, you can measure charge state using a hydrometer to measure the density of the electrolyte.  Probably not convenient for general use, mentioned here only for completeness.

[oded kishony]

A fellow I met at a marina showed me his hydro generator set up which seemd very simple and elegant. He simply had the boat prop attached to a generator with a belt/pully. I don't recall the details but a simple arrangement could be rigged to loosen the belt when not needed.

oded kishony

[Kailyst]

My SO is a Ham Operator and he gets wireless internet through www.winlink.org. We were once on a camping trip in West-By-God-Virginia and had e-mail and was able to send digital pics to friends. I don't know if this would work for ya'll, but may be worth checking out?

[s/v Faith]

My SO is a Ham Operator and he gets wireless internet through www.winlink.org. We were once on a camping trip in West-By-God-Virginia and had e-mail and was able to send digital pics to friends. I don't know if this would work for ya'll, but may be worth checking out?

  SOmething to check out, at the risk of driving this thread OT, is SCAMP.  This is the next, latest, thing that will allow email/data transfer across HAM without a TNC, but just by taking the audio streight into the sound card on your laptop.

 

[AdriftAtSea]

SSB radio can be used to get e-mail while in remote areas. 

As for remote power generation.

Towed Water Generators are excellent for long passages, but do add a significant drag to the boat in light air, not much of a problem in heavier winds.

Wind Generators are quite good for windy anchorages and harbors, but can be a danger to crew if not properly positioned and setup.  They are not as useful on downwind passages, but can be used on upwind passages fairly well, provided they are located to not get in the way of the sails.  On the smaller boats on this forum, they can be a bit difficult to setup/position without being a hazard.

Solar Panels:  Probably your best option, especially in the lower latitudes, where the sun is stronger.  Remember, when you are sizing solar panels, that in many areas they only really provide five hours of power, not 24 hours, so you need to size them with that in mind.

Gas or Diesel Powered Generators:  Generally, the last resort in my opinion, especially on smaller boats.  They add a lot of weight by themselves and then adding sufficient fuel to run them for extended periods of time adds significant weight and ongoing costs.

Computers can be a good thing, especially if you have them setup to do multiple things, like passage planning, weather fax, chartplotting, e-mail, and such.  The real issues with computers are sensitivity to water, corrosion, bad power and their relatively high energy demands.   In many new, more modern harbors and marinas, you can get broadband internet access via a WiFi card, and along the coasts of more civilized areas, you can often use cellular networks to get a slower, but fairly reliable connection.  One thing that can help computers is frequent use, as the heat of their operation can help drive out the moisture, and help keep the computer from suffering corrosion problems.

As a network engineer, I'll be happy to answer any "geeky" questions via PM.  :D

[Zen]

Good advice on the computers. I had figured on when not in use, keeping it in a ziplock bag with some of those moisture absorb things.

[Ol' Coot]

I know many of you are advocates of solar power on your boats.  Given an unlimited budget, it seems one could spend as much (or more) on panels and regulating systems as on sails.

Harbor Freight has a set of 3 panels (12" x 36" each) that they claim will output 45 watts.  Price is approx. $200. 

Does anyone have any experience with these?  Any thoughts?

[Godot]

It sounds like a great deal.  I mean, a REALLY great deal.  Which worries me.

Not all manufacturers rate their panels the same way.  50 Watts from Manufacturer 'A' may be 30 Watts from Manufacturer 'B'.  Harbor Freight doesn't mention the manufacturer.

Not all panels are designed to handle the rigours of being on a working sail boat.  There are waterproofness issues, impact resistant issues, heat sensitivity issues, wiring issues, fastening issues, and who knows what other issues.  Some of their ads (of more expensive panels) mention use on RV's, cars, and boats.  This one doesn't.  Now I don't know; but it would concern me if I where to buy it.

Now, these panels may be perfectly fine, especially if you are not sailing far abroad; but the catalog entry makes me nervous.  I personally would probably spend a bit more on something of a known quantity.  If I had a cabin out in the woods someplace, I might be more tempted to try these out.  Heck, I might buy two or three sets.  It kind of sounds like what they are intended for, anyhow.

[Fortis]

If your cabin was in the woods, it would be overshadowed too much of the time to make solar power workable.

;D

[s/v Faith]

For a couple hundred bucks you can get a fairly nice panel if you shop the hippie, alt energy type places.

Here is a good tree hugger, get off the grid site.

Link to altenergystore.com section on solar panels

  I like that site allot, as it also provides as much info on Solar energy you might want.  Other 'marine' sites offer much higher prices, and try to sell you things you don't need like charge controllers (needed only for high current systems, you can read more on the link I sent you.

    A quick glance at the 1-50w link on the site above tells me the prices have gone up.  I got my 80w panel from them maybe 2 years ago, and paid less then $200.

  I think it was listed in their closeout section (Phillips / BP panel, very high quality).

[Captain Smollett]

    A quick glance at the 1-50w link on the site above tells me the prices have gone up. 

True, but efficiencies are finally going up again, too.  While this has not yet filtered down the consumer yet, I read just last week that some solar panels are hitting 30% now.  If that number continues to rise, it will soon be economically stupid to NOT implement solar on a large scale (low conversion efficiency is one of the big thing holding back wide scale adoption).

My point is maybe -- MAYBE -- some of that increase in price is going to the research needed to get the efficiency higher.

[CapnK]

John - I saw a story that quoted a 40% efficiency rating. Now, how long til that trickles down to us is a matter of conjecture. It seems that the solar industry has plenty of snake oil salesmen in it. :)

OC - I have a 50 watt 'designed for boats' panel on my boat, and I plan to supplement it with a wind generator at some point in time. It came with a smart charger as a set, and retail was around $500-550 IIRC. Re: the HF panels: I think that I would want to spend that money on a panel(s) which are more of a known quantity and quality. Some HF stuff is pretty good, but sometimes it's kind of dicey, in my experience. What is HF's return policy? That said: For less than the price of my 50 watt panel, you could get 90 watts worth, and they just might be good... :D

Just my $0.02.

Plus a lil Grog. :)

[Captain Smollett]

John - I saw a story that quoted a 40% efficiency rating.

Could very well have been the same article and I just remembered wrong.  It was only a week ago or so. 

[AdriftAtSea]

Just be careful.  A lot of the panels are not designed for marine use, and will have corrosion issues after a very short period of time.   Also,  you might want to check on the warrranty and the type of crystal they use.   The last thing to find out is how many cells are in the panels.  The better ones have enough cells to make up for some shading...the cheaper ones don't—and won't produce sufficient voltage to charge the batteries if they're shaded at all. 

[s/v Faith]

.....The last thing to find out is how many cells are in the panels.  The better ones have enough cells to make up for some shading...the cheaper ones don't—and won't produce sufficient voltage to charge the batteries if they're shaded at all. 

  Actually, it is not dependant on the number of cells.  It has move to do with the construction of the panel.  In most panels, a shaded cell not only fails to produce current but becomes a resistive load.  Some panels try to decrease this effect with the addition of another PN junction (like a diode) between cells, to protect against this reverse current flow.  Many do not engineer this additional failure point into their panels, electing not to accept the slight decrease in efficiency it brings (max current is decreased).

  This is important, because shading on panels does not just decrease their efficiency but does so to a greater extent then you might expect.  If you shade 30% of a panel it might decrease the current produced by 75% or more. 

  It depends on the manufactures choices in engineering the panel, not so much on the number of cells.

[s/v Faith]

In answer to your original question.

....Harbor Freight has a set of 3 panels (12" x 36" each) that they claim will output 45 watts.  Price is approx. $200. 

Does anyone have any experience with these?  Any thoughts?

  Looking at the Harbor freight web site, I am thinking this is the set you are looking at;

Link to 45w solar panel array on HF



Quote from link;

Use the sun's power to run TVs, lights, computers and recharge 12VDC batteries!
Three 15 watt solar panels give you plenty of clean, quiet energy-- no fuel required
Power center is completely weatherproof and works under all light conditions
3, 6, 9, 12 volt DC adapter outlets
Easy-to-read LED charge indicator
Includes mounting hardware, light, 12V socket and battery clamps
Requires 12 volt storage battery and 300 watt power inverter (not included).
Maximum current, 3000 mA. 15 watts max per panel.
Peak voltage: 23.57 volts open current. Panel dimensions: 12.40'' x 36.42'' x 0.75''; Weight: 9.7 lbs.

  It seems like it might be hard to mount 3 12"x36" panels on a small boat, but even if you only used 2 of them it is gonna help with the energy budget some.  Nice capability to have even if not under way, not having to bring shore power aboard to maintain the battery.  For the price, I might give it a shot.  Sure would be nice to have more info on the panels, or at least be able to look at them before you bought them....

  I will be near the one in Pensacola next month, I could see if they have them instock and take a look for you (for what that would be worth).   Does HF have any stores near you? 

   

[Godot]

If your cabin was in the woods, it would be overshadowed too much of the time to make solar power workable.

;D