Solar Power

[barnakiel]

Originally Posted by goboatingnow

Look at the I/V curves, power derating with temperature, MPPT etc. This is why so many people get ouputs way below their expectations.

Dave

IMHO why many many installations yield less than nominal is because they are:

- shaded,
- not angled,
- poorly installed,
- poorly maintained.

On the other hand, never had any problem getting the nominal output (+/-) from a clean, unshaded, properly angled panel connected to the receiving end with properly sized wires.

MPPT is fine with big installations but the extra cost becomes justified only beyond some size. Up to that size it makes just as much sense to buy 'more' panel space - the same effect, but less cost.

As always it makes sense to use quality wires of proper size and, if to err, then always on the oversize side.

Some older regulators simply and only limit the voltage. Avoid these. Look for a smart (timed) PWM regulator as a minimum.

Rig the installation, check it for voltage drop, angle your panels and off you go with next to nominal output.

b.

[senormechanico]

Originally Posted by budgie smuggler

why did`nt i think of that..........A TOASTER............and another panel...........toast`l go well with my next coffee............ but my regulator/controller is only rated for 20 amps...........`spose a new regulator is out of the question................ A TOASTER....... new regulator...`nother panel....may need more batteries too......... who was it that talked me into solar???!!!!

Next step after the extra panels, extra batteries etc., is a BIGGER BOAT to hold all of that...

[barnakiel]

Toaster, yes. And a hair dryer for your lady ...

;-)
b.

[Bergovoy]

and a hand held 'massager'? (for the lady?)

[Pete7]

Originally Posted by senormechanico

Next step after the extra panels, extra batteries etc., is a BIGGER BOAT to hold all of that...

Or weigh in all the copper wiring and lead batteries at a scrap yard, then buy a shed load of candles.

Pete

[BudgieSmuggler]

i`ve decided to build a trailer & tow it behind my little boat. it will hold all the extra panels i need. i will incorperate a little cafe on the trailer so that i can visit popular anchorages selling espressos....ice cream...toasted sandwhiches.....and...ice......... please support my new business venture as i really need the money... my wife, kids & all my pets have all left me as no room for them.

[cat49]

sunpower solar is not sold by the panel anymore they only sell their products in a "turn key" installation from installers. does anyone know of any other high efficiency solar panels?

[Cotemar]

cat49,

I just had a friend buy 2 Sunpower panels two weeks ago in Boston Massachusetts.
They drop shipped them to his house in Port Jefferson Long Island NY.

Purchased the SunPower Panels from Munroelectric in Boston.
Contact Jeff Higgins jeffh@munroelectric.com direct line "508-536-2149".

[cat49]

that is wierd i emailed him and he responded
"Hi, thanks for your interest in Sunpower, unfortunately we are no longer selling Sunpower modules.
Sorry I cannot help you with that today.
Have a nice weekend,
Jeff"
then i called Sun power and they said installer sales only

[Cotemar]

Cat49,

Wow, My friend got his SunPower panels just in time.

I have another friend using these Sanyo panels.

Sanyo HIT-N235SE10 and the 230Watt version

[Lancerbye]

I have read through this post with a lot of tongue biting. I know that there have been a lot to terms in the electrical field bastardized by the marine industry primarily as marketing terms to confuse the average consumer. I will probably get flak for this but here goes trying to unconfuse some of the terms.
A/H is not proper terminology regardless what it says on your panel.
A=amps, which is an instantaneous measument of current at a given point.
Ah is the amount of amps available in a battery for one hour. ( not always true)
watts is (V * A) which is also an instantaneous measurement. When you pay your power bill you pay per KWh. An instantaneous measurement with a time frame.
So when you calculate the ouput of a solar system one has to take into consideration the current produced which changes throughout the day * the voltage at that time * the lenght of time this happens. Since we can't be sitting there with two meters and a stop watch to physically do this we have to rely on instruments that do this for us. Amp hours seems to be the most commonly used term in the marine industry. However at what voltage? The measurements for battery calculations are for nominal 12v even though we know that a 12 volt system is really 12.6 volts and charges at 13.7 or higher. I hope this adds to the confusion. lol

[noelex 77]

Originally Posted by Lancerbye

Amp hours seems to be the most commonly used term in the marine industry. However at what voltage? The measurements for battery calculations are for nominal 12v even though we know that a 12 volt system is really 12.6 volts and charges at 13.7 or higher. I hope this adds to the confusion. lol

As you point out Watt hours are a better measure of power in and out, but solar regulators (and yachtsmen) talk in terms of Amp hours.
There is a good reason for this.
Amp hours in and out can usually be added to reasonably to determine the state of charge.
The Amp hours in are produced at a higher voltage than the Amp hours out and this helps compensate for the batteries inefficiency in storing power.
The same calculation in Watt hours is not as useful.
Most solar regulators display Amp hours for this reason

[Feral Cement]

Originally Posted by budgie smuggler

i have a espresso coffee machine .......big trouble, i drink 10 cups a day ........ that`s an awful lot of power

I'll say. I'd be vibrating at about 930 Hz, a tinny B flat.

John

[SeaKing]

I am looking at these,

Aurinco solar panels

My battery bank is 800Ah,. I am considering installing 500 watts of solar on the boat, should have plenty room in the batteries for those real sunny days or to supply lots of current when "Everything" is on. Fridge, freezer, auto pilot, depthfinders, chart plotter, cabin fans, TV maybe, etc.

These panels are very thin, can be walked on and have a 17% conversion rate.

For the experts and experienced in solar, how do these panels look. What about my plan for 500 watts in panels, is that a good start. The boat will be in the tropics so I am expecting lots of sun.

What controller would be a good one to work with the twin engine/altenator setup I have.

[billyehh]

My solar regulator shows volts and amps, not amphours. That is a job for my battery monitor ( a Link 2000). It displays the amphours used since the battery was last charged usually late afternoon when my solar panels quit for the day. In the morning it displays how many amphours I have used overnight a negative number.

As the amps come flowing again, this negative number starts to reduce as the battery starts to recharge. Think of it like a gas gauge. The monitor also shows the amps going in and the voltage. These are instantaneous numbers only indicating that moment.

The solar regulator display is useful since it shows what your panels are actually prducing whereas the the amps on the monitor are showing what actually goes into the battery bank. The difference being what you are consuming at the moment. Remember that these are only instantneous amounts and amphours can only displayed on a proper battery monitoe