Current Strategies in Solar Power ?

[ConradG]

"Also, I would dearly love a washing machine, but the size and weight are currently an issue. Hopefully, someone will come up with a new design, but I suppose that's another topic. Thanks folks for your input! "

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Perhaps this one will fit your needs. Really efficient and solar powered too! They've been working on photosynthasis for quite some time now and it's really coming along!

(perhaps it will at least break the recent tension too?)

[Roy M]

Hmmm! That washing machine looks similar to the one I have used before, only I didn't have the plunger accessory package. As a real plus, one needn't be too concerned over whether it is AC or DC powered. It's truly green and energy efficient. Thank you for helping to redirect the conversation back to basics.

[barnakiel]

From a UK site the thing would cost me 1000 USD for same installation. This is 5 times more expensive than equivalent AGM for my case. I got 4 years of very abusive usage from my last set. The new thing would have to give me the minimum of 20 years service ... Not likely, is it.

b.

[ConradG]

Originally Posted by Roy M

Hmmm! That washing machine looks similar to the one I have used before, only I didn't have the plunger accessory package. As a real plus, one needn't be too concerned over whether it is AC or DC powered. It's truly green and energy efficient. Thank you for helping to redirect the conversation back to basics.

My Aunt introduced me to the accessory package when I was a kid. Quite an upgrade! Really gets the dirt out. More than doubles the cost of the machine though...but worth it IMHO. (seriously)

[SeaKing]

Getting back to the solar strategies, i just had a hardtop built and installed. Now I have a place for panels, several panels. I am thinking of initially going with one large panel in the 200 watt range. I am only in the beginning of my studying about the systems. My concern is what happens when you run the engines or have another source of charging available. how is that controlled.

[barnakiel]

You can run the engine early morning and then leave the rest of the job to the panels. I have not seen any controller to charge from the engine and from the panels at the same time (but it may exist). But there are controllers that combine solar and wind.

Alternator regulators with voltage sensing will not really appreciate the Voltage put in from the panels and some of them will refuse to charge while the panels are at work even if the batteries are not full yet. Much depends here on complexity of the system.

Calder discuses some of the aspects in his book and Payne does too.

b.

[SeaKing]

Originally Posted by barnakiel

I have not seen any controller to charge from the engine and from the panels at the same time (but it may exist).

So what do people do when they run the engines with alternators charging, manually switch the solar panels off or have independent battery banks.

I have a 3000 watt inverter/charger "Xantrex Freedom 30" and a house bank of 576 ampHrs. Each engine has an high amp alternator and I have a 6'5 KW generator. But I want to have solar also to cut back on the need to run an engine of any type.

[Bash]

Originally Posted by SeaKing

So what do people do when they run the engines with alternators charging, manually switch the solar panels off or have independent battery banks.

My controller shuts the panels off when a certain voltage is reached, which means that the shore-power charger or the engine alternator will take over automatically. I've set the system up so that the wind generator will usually turn itself off before the panels need shut themselves down.

However, I really don't need to use my engine anymore to charge the batteries. As a matter of fact, last weekend I forgot to turn the wind generator on when we went to bed, and in the morning my system was 90Ah down, but by early afternoon I was back to a full charge without using the engine.

[Roy M]

Folks, thank you very much for all of this great info. I feel like I've gone full circle, back to my original questions,now answered. Problem is, now I have a further question: Assuming I have this wonderful photovoltaic system that now produces most, if not all, of my charging needs, adding a wind charger as a backup seems pointless, unless...... I have read in Calder's book that the powerful charging of a wind unit can lead to an excess of charging capacity. He suggests diverting the excess current to a water heater element to make hot water, via a charge-divert regulator. Sounds like another way to store energy that has immediate benefits. Has anyone done this? Any suggested resources for these regulators?

[Bash]

If you sail at night, if you sail during the winter months, or if your cruising plans include higher latitudes, a wind generator is a valuable asset.

I haven't yet installed a charge-divert regulator, but I'm certainly getting close to that point. Eager to hear any success stories out there. It seems, from the spotty advice that I've been getting, that the tricky part is the heating element. I'd love to find a water heater that would use both a 110v AC element and a 12v DC element at the same time.

[cal40john]

Originally Posted by ChuckSK

Hello Roy.


Because the panels are in series, the controller comes on very early in the morning and stays on until late in the evening. Very little light produces enough voltage to turn the controller on. The benefit of this has not been measured, but it can't hurt.


Good Luck
Chuck

I'd be interested in seeing if being in series really does make any difference in this case. Perhaps as soon as soon as you see usable voltage from the series set of panels, bypass all but one with a short and see what the voltage is then. From the I-V curves below, since you're using an MPPT controller you will be operating at the knee of the curve. Even at 1/5 of max sun on the panels they would be putting out around 17 volts, enough to make use of the available output of the panels. Drawing a line through the knees makes it look like any amount of light is going to produce enough voltage to turn on the controller, though the amount of current is so small it hardly matters anyway.

On the other hand it looks like if you're cruising the Red Sea and your panels are hotter than stink, then it would make a difference.

John


From:
Electrical Characteristics of Solar Panels or PV Modules - AltE

[ChuckSK]

cal40john

The controller turns on when the array voltage exceeds the battery voltage. I will try to measure the watt-hours produced between the time the controller turns on and the time when the array voltage equals 4 times the battery voltage. That would be a measure of the benefit.

Chuck

[hellosailor]

Seaking-
"So what do people do when they run the engines with alternators charging,"
I suspect that most folks just have no idea what is going on, and they just assume it all works together. While the really astute ones disconnect the panels, either manually or with a simple relay.
Considering how many boats are built with the alternator sense lead just tied to the output (what's called a "one wire" installation)...it wouldn't surprise me to find a lot of boats just had panels added in, with no fancy source switching considered.

[barnakiel]

And, in any case, do use the engine.

This would be very bad for the engine if, once you do not need it to make electricity, you simply stopped using it. That is to say, unless you winterize the beast.

I think an unloved child of the marriage with solar and wind power is (the fact of) some users not using the engines. According to a bunch of smart engine asses not using the engine can in fact be worse than any other bad engine practice.

Use it or lose it. (Or winterize it!)

b.

[Strygaldwir]

Hey Chester!

You mostly lose the output of the panels in that case! But, at 7 amps for a 200 watt panel vs 50-150 amps from the engine, you won't miss it much you'll probably only be running the engines for an hour or 2? I am still of the opinion your better off using the propulsion engines for just that! Moving the boat.

Now, an additional issue is balancing Wind generator out put with solar panels. THAT get's interesting.