What type of Solar?

[skipgundlach]

PS here's a link to a tech sheet which shows the different efficiencies of the different wattage panels with the same footprint:

https://us.sunpower.com/sites/sunpow...nical-spec.pdf

[john61ct]

Originally Posted by boat_alexandra

Another type of solar is a parabolic reflecting dish. I have one of these installed and it can be used for:

1) cooking (as hot as a stove) boils water in a few minutes
2) making tar, charcoal, and combustible gas from any carbon base input.
3) sewage treatment (makes charcoal and gas)
4) steam engine (I have a small one)
5) concentrate (even partial) moonlight to make a light as bright as a headlamp, useful for reading at night.
6) cool water below ambient temperature at night, can make ice at 10 celcius.

None of these useful cases require any batteries, wires or electricity!

Pics and links please

[Paul L]

Originally Posted by skipgundlach

PS here's a link to a tech sheet which shows the different efficiencies of the different wattage panels with the same footprint:

https://us.sunpower.com/sites/sunpow...nical-spec.pdf

Note that many of the third part flex panels are built with Sun power cells, so you don't need Sun power panels to get the same density.

[Mr B]

My two panels just arrived, There is no sun on them,
My body standing in front of them made the current output vary a bit,
$324-00 AUD delivered with 2 X Two into one MC4 connectors,
2 X 250 Watt Panels, Total 500 Watts,
They will be placed on the dinghy davits with a single bar through the centre so they can be tilted during the day to face the sun,
There is no shading out there,
Single 30 amp MPPT controller, Was about $40-00 AUD, Delivered, But I may have to get another controller as this one is borderline for the power output,
13.36 was with both panels connected together,
Comments Welcome,
Cheers, Brian,

[seandepagnier]

Originally Posted by john61ct

Pics and links please

I will post when I get the tracking working... That part does require electricity. So far I am using it at a dock, or with a stern anchor.

[GTom]

Originally Posted by boat_alexandra

I will post when I get the tracking working... That part does require electricity. So far I am using it at a dock, or with a stern anchor.

Manual "tracking"? I am skeptical of active tracking on the boat, I suspect the constant readjustment would consume way too much power.

[Mike OReilly]

My system consists of four separate panels, all parallel to one MPPT controller (Victron):
2x150 watts, rigid, mono crystalline
2x 50 watts, semi-flex, mon crystalline

The semi-flex must be five years old now. They were expensive, bought from Aurinco (American-made) which is sadly no longer in business. They are mounted on metal backing, and seem very durable. I have them on deck, in an angle bracket so they can chase the sun.

The rigid are about three years old. Bought from a Quebec maker.

To date all panels appear to be functioning to spec. I’ve seen no degradation of the semi-flex, but with my set up, they don’t “flex” very much.

[john61ct]

Originally Posted by Mike OReilly

My system consists of four separate panels, all parallel to one MPPT controller (Victron)

You will see much more total output adding a cheap small controller so each SC only has a matching pair attached.

Victron 75/15 goes for $85 these days, mayvbe $25 more for the dongle functionality.

Or even a $40 PWM

[Mike OReilly]

Originally Posted by john61ct

You will see much more total output adding a cheap small controller so each SC only has a matching pair attached.

Victron 75/15 goes for $85 these days, mayvbe $25 more for the dongle functionality.

Or even a $40 PWM

Thanks John, I’m sure that’s true. If I ever need to squeeze more power out of the system I might consider this. As it is, my 400 watts on the single Victron MPPT seems to keep my 320 Ah bank well maintained. It almost always hits float by early afternoon, even in the northern light of Newfoundland.

(I also have a 400 watt wind gen on a separate controller).

So I don’t need more charging capacity. What I really want is a larger bank. I’d like is to add another 100+ Ah, but not sure if dropping a new battery into a the system is wise given that these current batts are now 3+ years old.

[skipgundlach]

Originally Posted by Paul L

Note that many of the third part flex panels are built with Sun power cells, so you don't need Sun power panels to get the same density.

That's quite correct. Sunpower cells are so dominant that the 3rd party builder will be sure to cite that in their advertising and specs. Note that Mr. B's panels cite using Kyocera cells in his pic above...

In the end, it's the warranty, the standards (such as the most severe salt test, being that we're at sea), and the cost to put up however many watts you can fit and manage (controllers are pretty expensive, too!)...

Good call; I'd forgotten to mention that.

[skipgundlach]

Originally Posted by Mike OReilly

Thanks John, I’m sure that’s true. If I ever need to squeeze more power out of the system I might consider this. As it is, my 400 watts on the single Victron MPPT seems to keep my 320 Ah bank well maintained. It almost always hits float by early afternoon, even in the northern light of Newfoundland.

(I also have a 400 watt wind gen on a separate controller).

So I don’t need more charging capacity. What I really want is a larger bank. I’d like is to add another 100+ Ah, but not sure if dropping a new battery into a the system is wise given that these current batts are now 3+ years old.

No, it's not. 3 years, if they hadn't been perfectly maintained, is well into the life cycle of the typical battery. If they haven't been perfectly maintained, they may be on the way out.

Have they spent their entire lives on your system you described (and C100 every day, essentially)? If so, they likely can go a lot longer. But you will have the inevitable age difference (efficacy of LA batts declines over time regardless of how well you treat them).

I can't imagine any battery pro advising you to add new batts to a 3YO system. Best to equalize them, advertise their resting SGR (specific gravity reading) and sell them to help pay for a new bank of the size you want...

If you read my story link, you know that I sold the pair which was still good in my system when I started over...

However, your system seems to be well set up. In your area, how much does the wind gen contribute to your normal-topped-up state? And, for that matter, if you're always full by the end of the day, why do you need a bigger bank?

Just thinking out loud...

[john61ct]

Originally Posted by Mike OReilly

not sure if dropping a new battery into a the system is wise given that these current batts are now 3+ years old.

Not bad for the bank, but the lifetime you get out of the new batt will be only what's left on the old ones.

If you are in a location where you might get something for a worn but working bank secondhand, do that and buy new matching all at once, is my reco.

[Mike OReilly]

(This response has turned out to be longer than expected. I hope the OP is benefitting… )

Thanks Skip/John, yes… I knew the right answer, but was hoping to be wrong .

Skip: I’m sure my batteries are less than perfect. They suffered from a season of poor charging due to an inadequate controller. The last two seasons they’ve been run through the MPPT, and seem to be doing great, but they take the normal beating most cruisers give their banks. I don’t baby them, but now that I know more than I did, I try and monitor them closely.

Wind input is more variable than solar. I’d estimate we get 10-15% of our total amps from the wind gen. Solar is by far the biggest contributor. But this is partly due to the priority given to solar. I have the wind gen on a simple voltage cut off controller, and it is usually set below the absorbtion voltage so as to not damage the batteries.

So there are many times when the the wind gen could be contributing amps, but gets cut off b/c the solar is providing all that is needed. Where the wind gen really helps is when it is overcast and stormy, and overnight.

The desire for a bigger bank is basically to extend the time we can go without significant solar. Since my charging system can seemingly handle an additional battery, it seems like a good idea.

To be clear, it’s not a burning need. Last season over the 3 months we were completely off the dock I had to run the gas portable generator for about 3 hours. But I will actively manage onboard loads if we’re getting into trouble.

I’ll think about selling and buying all new. It’s a big cost for me as a small-budget cruiser though.

John: good idea about using an existing older battery now, and planning to replace them all later. But how do I really know what I’m getting unless I do a 20 load test? If I can’t do that, aren’t I just gambling with the outcome? Is this still better than dropping in a new, cheap, but known 12v battery?

[john61ct]

I did not recommend buying secondhand, only selling.

Sounds like you can just wait, use the genset a bit more, then when that gets to be a pain, do a new & bigger bank.

If you keep your eye out for a great deal on same-model batts in the meantime that's always an option. Rather than a full 20-hour test, just compare via a standard load for a shorter time to your existing batts, long as the incoming is better or around the same, should be fine for at least another year or two.

[Mike OReilly]

Originally Posted by john61ct

I did not recommend buying secondhand, only selling.

Sounds like you can just wait, use the genset a bit more, then when that gets to be a pain, do a new & bigger bank.

If you keep your eye out for a great deal on same-model batts in the meantime that's always an option. Rather than a full 20-hour test, just compare via a standard load for a shorter time to your existing batts, long as the incoming is better or around the same, should be fine for at least another year or two.

Sorry John, my apologies. Too much flipping back and forth, trying to be efficient in responding. You definitely did not recommend buying second hand. My bad.

You’re probably right … best to wait. It’s not a burning need. And our plans for the coming season is far more modest than previous.

What I really should do is reconfigure my battery compartment to accept 6v batts. I don’t quite have the height for them right now, which is why I’ve stuck with Group 31.