Solar question(s)

[Critter]

OK, maybe this'll generate a little traffic.

I have the Genasun controller, now I'm shopping for solar panels. What are the pros and cons between monocrystalline and multicrystalline panels? Seems I recall reading somewhere that one is less affected by small shadows, e.g. from backstay, antennas etc.

Max

[BobJ]

Max, I'm no guru on this stuff but since no one else has answered (and we like the chatter in the dugout) . . .

I think the solid panels are either mono or multi-crystaline and are most affected by shadows, even from a stay, etc. That's why most people mount them on the stern pulpit behind everything, or on one of those lovely stern arches.

The "amorphous" panels are often the flexible type and although they're more tolerant of shadows and can be installed more places, they are much less efficient. They also appear to be far more expensive per watt than the solid panels.

A good place to go is No. Arizona Wind and Sun (www.windsun.com). Great prices and tons of information. They have a forum where a couple of us used to post (Hi, Alan). I got a pair of Kyocera KC-40T 43 watters from them in 2005, which I control with a FlexCharge PV7-D dual-bank controller from your favorite retail store (WM). I mounted them to a SS tube which spans the transom, using those white plastic block-shaped rail clamps from your favorite retail store. This helps a lot because I can pivot the panels up/down to improve the angle and efficiency. I'm happy with the setup - works fine - no problems.

[AlanH]

Here's another plug for Northern Arizona Wind and Sun. I bought two 60-watt Kyocera panels and when I got them I was taken aback at how big they were. I e-mailed the guys at the store and they did the exchange for two 40-watt panels and refunded the difference, no problem.

Good people.

Just in case you're interested....I had two 40 watt panels on a beefed-up stern pulpit on Ankle Biter. The boat was moving so much that a shadow didn't have enough time to sit in one place and significantly effect transmission, so the backstay was irrelevant. I had an e-bay special used 30-watt panel mounted over the companionway. This was a semi-waste of time, as it was almost always shaded by the main or the boom or something. The other e-bay special 30-watt panel was loose. I had a line on it that I could wrap around an unused winch, and a 15 foot long cord from the panel to the regulator. During the day I'd just put it out in the cockpit, with the line as insurance that it wouldn't fall overboard. That worked out pretty well. Total array size was 140 watts, all rigid panels.

That array powered all my SSB use and since I lost my windvane several days out, it powered the Autohelm 2000 that basically drove the boat all the way to Hawaii. I also had a mapping GPS going almost all the time, since that was my knotmeter.

I'd run the batteries down pretty well during the night and they'd get up to about 13 v during the day. Every 3-4 days I'd pull out the little portable inverter and charge my laptops battery. Don't run the laptop, plugged in to the inverter, it's a lot less efficient than charging the laptops battery and then running the laptop off of its own battery.

Finally you will save WADS of energy by using LED bulbs in your navigation lights. Yes, they're expensive, but they are piddly compared to what you will have to go through, if you're on a small boat without an engine, to keep your batteries charged if you're using incandescant nav lights.

Oh, one last thing on energy. You're supposed to have a strobe light "at the masthead" right? You can power that strobe light from here to Tokyo and back on one single 6 volt lantern battery. Yes, the strobe nominally says it's supposed to have 12 volts, but the capacitor in the strobe will store up charge from the 6 volt battery and cause the strobe to discharge just fine. It just discharges a bit less often. My point is that if the doodoo hits the fan and you seriously have no juice, you can wire your strobe to an $10.95 lantern battery and it will blink all the way to Hawaii, telling all the big ships exactly where you are the whole way.

[BobJ]

Alan, we're not requiring strobes this time but I figure the next sucker . . . er, 2012 SHTP R/C . . . will require them again. I'm planning to mount a Velleman HAA40 on top of my OGM Tri-Anchor light (like Rich Rollins did on Libations II).

The Velleman flashes too fast (approx. 2x/sec.). How much will a 6v lantern battery slow it down?

Anyway that's good to know - maybe I'll install it now while the mast is laying on Svend's mast dock. Anybody know of a reason I can't just epoxy the plastic base of the strobe right onto the metal top of the OGM light? I understand the LED tricolors don't get hot, so other than probably voiding the OGM warranty (it's new) can you think of any issues?

[jfoster]

Originally Posted by BobJ

Alan, we're not requiring strobes this time but I figure the next sucker . . . er, 2012 SHTP R/C . . . will require them again. I'm planning to mount a Velleman HAA40 on top of my OGM Tri-Anchor light (like Rich Rollins did on Libations II).

The Velleman flashes too fast (approx. 2x/sec.). How much will a 6v lantern battery slow it down?

Anyway that's good to know - maybe I'll install it now while the mast is laying on Svend's mast dock. Anybody know of a reason I can't just epoxy the plastic base of the strobe right onto the metal top of the OGM light? I understand the LED tricolors don't get hot, so other than probably voiding the OGM warranty (it's new) can you think of any issues?

And the reason you don't just get a 6v lantern battery and post the answer to the flash rate question here would be? (Yeah, yeah it is tax season.....(grin)

Remember to use Gougeon's West System's G-Flex epoxy when bonding the plastic to the metal, rather than the regular formulation.

John
Blueberry
http://www.facebook.com/photo.php?pi...&id=1264376108

[haulback]

Another vote for the Kyocera 43 watt panels - in ocean-going trim I carry 5 of them running through a MPPT controller. This is my 3rd solar installation on the boat and seems to be the best so far. I have had a couple of the flexible panels (which were a bit of a disappointment as far as longevity and output were concerned - but they did look nice!!) and a 50 watt Siemens which performed well until it got washed overboard in a knockdown (not it's own fault) These were replaced by a couple cheap rigid 35 watt no-name Indian panels, which while not great, were better than nothing.
I think no matter what type of panel you decide on, the rule-of-thumb that 'more is better' is the best design principle to follow to optimize output when considering a solar array installation

[AlanH]

Originally Posted by BobJ

Alan, we're not requiring strobes this time but I figure the next sucker . . . er, 2012 SHTP R/C . . . will require them again. I'm planning to mount a Velleman HAA40 on top of my OGM Tri-Anchor light (like Rich Rollins did on Libations II).

The Velleman flashes too fast (approx. 2x/sec.). How much will a 6v lantern battery slow it down?

Anyway that's good to know - maybe I'll install it now while the mast is laying on Svend's mast dock. Anybody know of a reason I can't just epoxy the plastic base of the strobe right onto the metal top of the OGM light? I understand the LED tricolors don't get hot, so other than probably voiding the OGM warranty (it's new) can you think of any issues?

I never actually measured it, but probably about by 3/4. I had a strobe about eight feet up the backstay on Ankle Biter and I used that in addition to regular Nav Lights. I seldom hoisted the "pig stick". That strobe probably went off about every two seconds, something like that.

[BobJ]

I got a 6v battery today and did a carefully controlled double-blind reverse osmosis test on the little strobe. It's supposed to flash 90-110x/minute with 12v. With 6v it flashed 90x/minute, so about the same. Study concluded.

I think I'll still stick it up there so I'll feel like a world cruiser or something. It doesn't weigh anything.

Now back to Max's solar thread.

[sleddog]

Having seen solar panels waterskiing behind the boat, it is a good idea to have a safety line on each panel no matter where it's located.

Something that can be forgotten: When running in the trades, solar panels in the SHTP likely will be shaded by the headsail/spinny from after local apparent noon to near sunset, or about 40% of the daylight hours. Best to plan capacity with that in mind.

[jfoster]

Originally Posted by sleddog

SNIP Something that can be forgotten: When running in the trades, solar panels in the SHTP likely will be shaded by the headsail/spinny from after local apparent noon to near sunset, or about 40% of the daylight hours. Best to plan capacity with that in mind.

Come to think of it that would apply to "Some boats with Back Sails, not Front Sails"
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John Foster
Blueberry