Is this a good solar panel?

[shanker]

Ok, I'm totally confused with solar. Lots of good info I've been reading but my head is getting a little sore. I'm worried about the comments being made about the junk that is out there and I'm not sure how to tell. Is there a straight forward check list that one can use to eliminate the crap that is being sold?

I found this panel which seems to be a pretty good deal. 30 watts for $99. Can I hear from those that get this stuff with a thumbs up or down and more importantly, why?

http://www.ul-solar.com/ProductDetails.asp?ProductCode=STP030P

 

[taichi]

On this same site the 30W marine panel with Waterproof Charge Controller is $179 - I wouln't buy a solar panel without some type of regulator to keep your battery from being overcharged - there are different types of regulators, some are pretty simple but If your on a boater site asking I'm thinking you should spend a little more and get waterproof with a regulator. As long as you buy from a vendor in the US with a warrantee you should be safe, I see alot of crap on EBAY made in China.

 

[Bill Roosa]

At $99/30= $3.3/watt I'm not thinking this is much of a deal. You can get them for around $1.5 or lower if you shop around. Also 30 watts is a smokin 2 amps in full sun and with the panel tilted directly at the sun. needless to say you are never going to get even those 2 amps as long as you are north of the Tropic of Cancer.
Unless you have a 20 AH battery bank (probably made out of protable drill batteires I'm guessing) then a 30 watt panel does not need a charge controler, just a blocking diode to keep the microscopic AH you gathered during the day from leaking back out at night.
Perhaps you are just needing a trickel charger for the winter to keep the batts up. That is about all this panel is good for.
How do you intend to use solar on your boat?, recharge after a weekend out, suppliment the alternator during a cruise?

 

[taichi]

The amp rating is per hour - it adds up over time. For what it's worth I have 1.5 amp rated trickle chargers on both my sailboat and my fishing boat and the batteries are always fully charged when I get the the boat. I don't have an alternator on my engine.
Shankar looks to have a Hunter 260 so I'm assuming you just daysailing similar to me with an outboard and maybe just want a charged battery for lights.
Also by my humble electrical knowledge from when I got my HAM radio license; a 30 watt panel would max close to 2.5 watts, and there remakably efficient these days, they put out a little juice even when it's cloudy.

Bill is correct thought that if you want to use a solar panel to fry bacon in your hotplate or something - then you would pretty much need to cover your boat in solar panels.

 

[shanker]

I guess I didn't present enough information. I was simply referring to the quality of this solar panel. That seems as cheap as I've seen for 30 watts (cost wise). I'm trying to figure out what a decent amp put out would be for a 30 watt panel and if this one has it.

Yes, my needs are simply to top up my batteries through the week. I will mostly sail on weekends and have no real power draws on the boat. I have a GPS, radio as the only real draws. Sail on the weekends and solar will top up during the week. I switched my lights over to LED. I will be spending the odd night out on the water but I am also planning two, week long trips. I currently have a 5 watt trickle charger but I figure that between a 30 watt panel and my motor, I should be able to make it through a week on the boat. I also have a battery charger on the boat that I could plug into at a marina if required.

I just find this whole electricity thing confusing. I'm so much more comfortable machining the swivel bracket that I've designed to mount it on. I can see and feel it...this electricity is illusive in my mind.

I really appreciate your input.