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

[Frank]

we use a simple foldaway solar panel.Although limited as to its charging ability, it did bring up a dead battery in 2 1/2 hrs of sun enough for a start.These units fold away into the size of a book. Still can't load pics here, so I put one in my gallery.The beauty is they store small,are light and you move them around to follow the sun. KISS . Generaters seem complicated to this simple mind  ;)

[s/v Faith]

Reality has met my energy budget and it has not worked out well.

All of my numbers were based on 6a coming from the outboard for around 6 hours a day.  We have motored very little compared to that and have used much more power then the budget allowed.

  For instance the Engle fridge that had a stated draw of 700ma in fridge mode to 2.5a in freezer mode actually draws more (around 2a)* when it runs which is between 40% and 75% of the time.  I had figured a worst case of 24 x .7 for 16.5 ah... it is something like 35ah in practice.  This was the majority of my 25ah budget.  I have also used more power running the inverter to use the laptop.  It is rated at 400w, and draws 6.5a with the computer off and charging, but draws a whopping 10a with the computer running. Just 2 hours on the computer a day doubles what I was counting on.

  So, the 6a outboard charging system that is not used much, and my ~ 60w of solar panels (one hard panel and 2 x 20w flexible panels) should provide a max charge of 5a, (have never seen more then 3a). 

Revised energy budget requires about 60ah.  I can expect only about half of what I need from the solar panels I have, and I don't want to go much larger.  I know I can get a little more if I 'vector' the panels to track the sun but I don't see this as a realistic option on my boat.

  I have looked at wind, and generally like the Rutland wind generators both for their output on light wind, and their reputation for being quiet.

The model  I like the the Rutland 503, it is very small and will fit nicely on a mount my stern rail.  It is rated at '60 watts' but more digging shows it only makes the 5a at higher wind speeds.  It is marketed as a wind 'trickle charger'.

The Rutland 913 on the other hand makes about twice the output but  is also much bigger and will require a more substantial mount.

I have considered a small 2 stroke generator until I can get this worked out, but don't like this as a long term solution.  Of course eliminating the fridge would make the system work as it stands, but my Fist mate is more important to me then making the energy budget simple.

Anyone got any thoughts?

* I have added a link 10 mattery monitor to the system.... No longer kiss.  :P

[Captain Smollett]

Ditch the fridge.  Lots of folks cruise without refridgeration.  Hold them up as examples and maybe Rose will see it as more of a convenience than a necessity?

For my plans, I would like to plan toward a 0 ah energy budget.  I view reliance on electricity as one of those 'traps' we often talk about.  I know 0 is probably not realistic, but that's the goal I am working toward.

[s/v Faith]

Ditch the fridge.  Lots of folks cruise without refridgeration.  Hold them up as examples and maybe Rose will see it as more of a convenience than a necessity?.....

Well.... we just spent a week with James and Mei... if THEY could not talk her into it I think I had better just figure it out...  :P

[Captain Smollett]

Well.... we just spent a week with James and Mei... if THEY could not talk her into it I think I had better just figure it out...  :P

Good point.   :)

Is it worthwhile to ask the question "what do we need refridgeration for?"  I mean, a LOT of stuff can go weeks without the fridge if we just give ourselves over to it.  Becky and I were talking just tonight about eggs and she said "but why does FDA say that they have to refridgerated?" if many people say the really DON'T need the cold.  It's a fair point: "why?"

I'm sorry to hear your electrical budget is not meeting your needs.  There's a lesson for us all in what you wrote.

[AdriftAtSea]

s/v Faith-

Just curious, which model/size Engel do you have???

[CharlieJ]

Eggs can go for months with no refrigeration, but there's a kicker- they have to have NEVER been refrigerated. Once they've been in the cooler, they won't last nearly as long.

But there's been some very good points made here. MANY many things we stick in the frig at home simply are there as a convienient storage spot- they don't need to be refrigerated.

And I've always found, in talking to longer term cruisers, the frig is almost a certainty to poop out on you sometime down the line.

Laura and I don't use our ice box to keep food, other than maybe the first few days out, when we might have some frozen meals prepackaged in there. And we feel we eat quite well. Now we might stick a hunk of cheese in there, or maybe a Snicker bar or two, but that not a normal thing.

[CharlieJ]

On another note- when I lived aboard the tri, I had a wind charger atop the mizzen mast- An AmpAir 50. That was replaced by the AmpAir 100, but I don't know if it's still built.

we provided all of our amps using that wind charger, except when in places where wind simplye could not get to us normally- and there were a few of those.

I also carried a small Honda gas generator, to use in those few times when the generator wasn't doing it.

But they are ALL noisy. Just yesterday I was working aboard a big tri with a wind genrator hanging in the rigging- In 15 mph winds, it's scary noisy. It's a two bladed unit. I've found that the more blades there are,, the quieter it runs.

Frankly I feel that for long term cruising use, a combination of the two is most likely the best alternative- a smaller wind generator, coupled with a good array of solar.

AND reducing you electrical needs to a minimum of course.

[s/v Faith]

That is pretty much what I was thinking too Charlie.  Adding wind, and maybe a small generator for times when there is not wind or sun.

  Right now, as I type this there are almost no food items in the fridge that would not be there if we did not have it.  There is mayo, not because we believe it has to be refrigerated, but because it is good cold.  Interestingly when we were at a restaurant we noticed they had squeeze bottles of Helmans mayo on the table.  On the bottle it said 'for restaurant use only'.  I read the ingredients, and compared them to helmans mayo in the store and they where the same. 

  We also have the beans and rice mix I have on my 'breakfast burrito's and a package of sliced turkey.  We keep regular 'store bought' eggs on the counter and they don't seem to go bad before we use them (usually within 2 weeks of purchase).

  The main reason we have the fridge is so the bottles of drinking water can be cold.  We drink the water out of the tank, but we run it through a britta water filter first to remove any taste.  We then keep it in recycled 'vitamin water' bottles that we like because they have big lids and are the right size.  We rinse them with hot soapy vinegar water between uses.

  The fridge we have is the Engle model 27.  It has a 22 quart capacity, and fits well just inside our V-berth.  I found a link to an Engle produced document that shows the current use patterns for this fridge, and it shows that the draw is very much dependant upon the difference between air temp and interior temp.  I still think it is a great unit, it just uses a bit more juice in practice then I expected.

  My wife enjoys living on a 26' boat with me, is content to go wherever, and do whatever seems like a good ideat to us at the time.  She does most of the cooking, and can do any task on the boat that needs to be done.  All she asked of the trip was to have room for her books, and some cold water to drink.  The fridge is a minor concession and it wil be worth it to keep it going even if I have to peddle a bicycle generator....   ;D

[s/v Faith]

Dan,

  It only took me an hour to find it, but here is a link to the graph I was talking about.  I think you may be interested since I believe we have the same model fridge.



On edit;

OBTW, this is the wind generator I am leaning twords;

The Rutland 913;



It is also available from these folks, for the same price ($995)

The other one I like, but I don't think it makes enough juice is;

The Rutland 503;



  If anyone finds them cheaper, I would appreciate hearing about it.
;)

Thanks to all who have particiapted, grog to all.  ;D

[AdriftAtSea]

s/v Faith-

Thanks for the power graph.  BTW, you might want to look at the KISS wind generator, as I believe it is about the same price as the Rutland 913, but generates considerably more power.  You can read about them HERE.  Here is a chart of the various wind gensets and the power they generate.

[s/v Faith]

Thanks for the suggestion Dan,

  The Kiss was one of the models I originally considered, but I think it's  'wingspan' is about 5'  :o  The Rutland 913 is 910mm, or about 36". 


The 503 is tiny at IIRC ~30".  I know the Kiss would only need a 12" longer mount pole to get the same height above deck, but I am already struggling trying to picture a 36" propeller rotating above my stern pulpit....

  Does anyone here have any experience with the Rutland?

[AdriftAtSea]

Good point.. the diameter is 58" IIRC.

[W Jones]

I have a Aerogen6 wind generator mounted on the port stern and am adding a 65watt solar panel. I don't know how the Aerogen6 compares to others but it is a fairly good sized unit, pretty quiet and seems very robust.

We also have a Engel fridge but ours is a 35. I hope to have enough power to run it, the tiller pilot and our lights and other loads.

Our boat is still on the hard so we don't know how its all going to work out. We plan to launch sometime in the spring. For the near future it will be in a marina with shore power and we will only need power for long weekends but we hope to get much further from the grid soon.

As far as not needing the fridge, I agree we could do without it. But we do like cold drinks and perishable meats. I have learned to hate dragging around a cooler and trying to keep ice in it. The first mate will put up with just about any kind of sacrifice to be on the water....as long as she has a COLD Mikes hard lemonade or a Margarita.  ;D

[s/v Faith]

W Jones,

  Good to see you post again.  The winches are working out great, grog to you.  ;D

I think the idea of the solar / wind combination is sound, I would recommend going with the largest solar array that does not scream that you are a fan of science fiction (not that there is anything wrong with that, I was a huge Dr. Who fan as a kid).

  I will say that I don't recommend Sunlinq solar panels.  I have two 25w panels on my bimini and I can hardly tell a difference when they are even hooked up.

  My real life current use has been about 25ah over the last couple weeks, that is my Engle 27 and a handheld GPS, and sometimes the VHF.  The draw was about twice that when it was hotter outside, as the fridge uses alot more juice when it has to work to keep cool (ambient temp and interior temp very different).

  I will be interested in your evaluation of the aerogen.  I have come across a couple Rutland's (all 913s, no 503s yet) and they have been really quiet.

 

[Bill NH]

I used to have a WindBugger on our trimaran for a few years.  Great output, supplied our entire energy budget...  but boy did it whine when the wind picked up!  I could tell wind speed from my bunk by the pitch of the sound it made.  Only consolation was that the amps went up as the noise went up.  All in all I think it was a fair bit louder than most other units; I'll be looking for something a bit quieter next time.
Bill

[AdriftAtSea]

My major project for the spring is working out the bugs in the solar panel mount setup.  From what I've seen, the two 130 W solar panels will provide all the electricity I need for the foreseeable future.  I am planning on upping the house bank to 400 amp-hours, from the current 200 amp-hours this spring as well.

I do have a stereo and a laptop that I generally use when at anchor, since I like to listen to music and write when I'm at anchor.  I also have the VHF and an Engel MT27 refrigerator. 

One thing I've found useful is to pre-freeze gatorade and juice in the two-liter bottles and then leave them in the refrigerator, along with what I need refrigerated... and the refrigerator rarely goes on with them there.

As for mayo... it really doesn't require refrigeration.  The main problem with mayo is that you have to prevent any bacteria from getting into it... Using a mayo squeeze bottle is probably the best way to do this.  If you have to use a spoon, always use a clean, unused spoon to get mayo out. 

[Grime]

I have a 6 watt solar panel and 2 batteries. Is it possible to connect the solar panel to both batteries and only use one battery at a time? That way I always have a fully charged battery. Or should I just connect both batteries together and let the solar panel charge both at the same time? Hope this makes since.

Ebay special on the solar panel. $34.99. Works great. One battery was completely down. I put the panel on the down one Wednesday night and last night I checked the volts and they were sitting at 12.08. So I guess it was worth the few bucks I paid.

Thanks for the advice,
David

[Bill NH]

Sounds good so far.  Keep it going and see if it brings your battery back to full charge.  For a lead-acid battery, 100% charge is 12.7 volts (after being at rest for 3 hours after charging).

The simplest way to charge both batteries at the same time without drawing on both is through an isolation diode.  It's completely hands off, but the diode will cause a voltage drop of 0.5 to 1.0 volts.  This will slow your charging and possibly limit your charging depending on your panel.

You can also install a simple SPDT Center Off switch on the solar panel hot wire to direct your charge.  Its like a 1-2-both battery switch, except lighter duty and way cheaper.  (with a 6W panel your max output current is 0.5 amps, so you're not talking alot of current...)   No voltage drop here but you have to manually choose which battery is being charged.

There are other devices to do what you want to do but they'll cost you more than the rest of your setup combined...   or if your batteries are the same type and in similar condition (age and use-wise) you can just parallel the batteries, charging both and using both as one big battery.

The best choice for you depends on how you use your batteries - is one a starting battery, or are they both for "house" loads?  Is it important to keep one battery as a "backup" while drawing on the other, or can you monitor your batteries to make sure you don't run everything down.  Is it an inconvenience, or a crisis, if you do?  What other charging options do you have?  Ultimately your choice will reflect your overall electrical strategy.

[skylark]

The easiest way would be to get a second solar panel and charge them seperately.

If you connect them, they should be of roughly the same "age", in other words they should have similar charge/discharge characteristics.  If you connect new batteries together with old batteries, the old batteries can reduce the total amp hours that the new batteries can put out.