Solar Power Virgin - Be Gentle Please

[S/V Alchemy]

Originally Posted by Dockhead

If it's really not harmful, then maybe I'm solving a problem I don't have.

You don't have that problem unless you develop an increasing leak, I suppose, around Day 28. Working the bilge pumps at 24.8 V versus 23.7 V (I assume they are 24 volt pumps) translates to more hours of runtime, doesn't it?

People will notice if the boat is a foot down in the water (usually), but at that point you have a world of trouble.

It's possible to rig a bilge switch to a flashing masthead light (it's a simple contact, after all) and if you tell the good folk around you where the keys are hidden it gives you time to fly down before the floorboards are awash.

[Dockhead]

Yikes! Well, that's everyone's nightmare, isn't it? A big enough leak will sink your boat in a marina connected to shore power, for that matter.

I think I'm just not going to think about that one. I religiously turn off my sea cocks, in any case. My rule is they get shut off any time I'm not spending the night on board.

For any freak accident involving say the packing gland, I've got insurance.

Originally Posted by S/V Alchemy

You don't have that problem unless you develop an increasing leak, I suppose, around Day 28. Working the bilge pumps at 24.8 V versus 23.7 V (I assume they are 24 volt pumps) translates to more hours of runtime, doesn't it?

People will notice if the boat is a foot down in the water (usually), but at that point you have a world of trouble.

It's possible to rig a bilge switch to a flashing masthead light (it's a simple contact, after all) and if you tell the good folk around you where the keys are hidden it gives you time to fly down before the floorboards are awash.

[Pete7]

DH, popped down to the boat yesterday as the yard were changing the cutlass bearing. Solar panel in full sun was giving 0.3 amps at 13.7v. Why so low? well the batteries are full and have replaced the 22 amp deficit from the weekend. The solar seems to be one of the few fit and forget things we have on board.

Your problem will be were to mount one though, but in front of the sprayhood looks promising and would keep the stern clear.

Pete

[Capn Morgan]

DH my worry with a wind generator in the Solent would be that you can get more than a stiff breeze that could damage the whole thing from time to time. Not sure I would want to leave it alone for a month like that. I would also overpower the solar array just in case. You can always use the power when you are onboard. Insurance or not, it would really hurt if she went down for whatever reason.

Nigel Calder makes a good analysis of these requirements in his book, I take it you have it, right?

[boatman61]

If going for a wind gen.... go for the Aerogen 4 or next up... they are the quietest, very rugged and reliable...
Used one for years and it coped with wind speeds of over 70kts with no problems.. they have a built in cut out..

[thinwater]

Don't fit crash bars over the panels; find a better spot. I've seen some that look ready for a prison riot, but it amounts to permanent shade.

Also, bird poop can reduce the output; they need occational cleaning.

[capn_billl]

A slow drip can sink a boat in a month. A bigger drip, coupled with a few downpours, can discharge the batteries with the bilge pumps in a couple of weeks, and almost sink a boat in the last two weeks, (I found that out the hard way). I would never , (again), leave a boat without some form of power for a month, no matter how big the batteries. A solar panel can provide enough power to keep the batteries toppod off just in case.

How many watts are the bilge pumps?? Mabe a good idea to get at least that big a panel?

[Dockhead]

Originally Posted by capn_billl

How many watts are the bilge pumps?? Mabe a good idea to get at least that big a panel?

I have four bilge pumps on board -- two jumbo Rules, 3700 gph each, and a couple of smaller ones. I'd have to cover the entire boat in solar panels to run them all continuously, I think.

But I get your point, and I guess you're right. I guess I'm going to have to think of something. Unless I can think of a decent spot for solar panels, it will have to be wind. I refuse to mount them above my davits like my father's boat -- windage, in the way, all that crap. On the doghouse in front of the sprayhood I think they'll be shaded by the boom, dorades, and other stuff there, but I'll check when I'm down at the boat soon. Probably it's going to need to be wind.

[MarkJ]

Originally Posted by Dockhead

Probably it's going to need to be wind.

This thread seems to have taken a full circle and come back and run over itself.

You are now racking up $2k for a wind generator when you wanted a 50 watt solar panel? Just to stop a non-existant drip after you turn the sea cocks off.

The 6 degrees of seperation means you know everone in the world.

But this cause and effect chain is just going to send you to hospital with high blood preasure and leave your wallet at the Chandlry.

A 440 amp hour battery bank would run a bilge pump for the month:
A Rule 26D 24 V runs at 1.9 amps for 500 gallons per hour.
Say your 'drip' is a gallon per hour so it switches on and offna dyour float switch is at a level where 2 gallons accumulate.

Do the maths and you are fine for a month! More.

Put in 10 gallons per hour and you are still OK!

Your 3,700 suckers at 25 amps --ok theres an equation I'm too lazy to do. But it dont run for long!

I sugest looking at this in the calm light of day - next week - when you have forgotten all about the fear factor

[goboatingnow]

So the big question, I guess, is whether the occasional month without a trickle charge is harmful to the batteries.

If it's really not harmful, then maybe I'm solving a problem I don't have.

Id agree with MarkJ, you really dont have a problem. Firstly a small panel will only trickle charge a bank as big as that , and in reality you dont need to trickle charge anything. Self discharge is meaningless over a period of a month. As for a wind generator, massive overkill and actually the hamble isnt as windy as some might think.

Leave it for a month or two or profil the batteries over a period. I dont think you need anything.

Dave

[Capn Morgan]

Originally Posted by MarkJ

This thread seems to have taken a full circle and come back and run over itself.

You are now racking up $2k for a wind generator when you wanted a 50 watt solar panel? Just to stop a non-existant drip after you turn the sea cocks off.

The 6 degrees of seperation means you know everone in the world.

But this cause and effect chain is just going to send you to hospital with high blood preasure and leave your wallet at the Chandlry.


I sugest looking at this in the calm light of day - next week - when you have forgotten all about the fear factor

Funny how this happens on boats.

[daddle]

Wind turbines are for pessimists: "It is going to be windy." Solar is for optimists: "It is going to be sunny."

That's my practical answer. My engineering answer depends on how much you want to spend and how much charge after what period you desire.

[Captain G]

Can anyone give me a little info on controllers? I have just installed two 135 watt Kyocera solar panels on my arch and will be starting wiring next week. Any tips would be appriciated.