Eco-Worthy 12v solar panels, Now drifting to... mono vs poly

I understand in cooler temps Voc will go up, but I was looking at going parallel, not series. And, if and when necessary, adding a third 100w panel.

And, yes, I asked because I wondered if the 12's would provide enough voltage for the mppt to work with. In hot weather, what kind of Voc would I be looking at from the 12's, and how much V is required to kick the controller into mppt mode?

My thinking is, with going paralleled, the amps will be there, without significant bucking. And I don't see me needing EQ type voltages in the summer, for two reasons, 1) temp compensation, 2) the batts should remain well topped up, so eq'ing should not be needed. So provided I can get say 14.6v on a hot day, I should be good to go.

BFL has pointed out previously, pwm does better in the heat, while mppt does better in the cold, but it's in the cold I need to max out every little watt. Does the mppt lose that much of an advantage in hot weather?

You can spend less and get the wiring too with a PWM controller like muddydogs did. Better yet would be a bit more on a 230w panel and the Eco-w. Then again if Eco-worthy is selling them together, they can replace the controller if it dies.


Oh wait, you are above the boarder. Shipping cost must be a factor too.

jrnymn7 wrote:
I'm looking at something like this:

http://www.eco-worthy.com/catalog/mppt-series-complete-200w2100w-grid-systems-with-mppt-controller-p-325.html

??? Will the 20a mppt work o.k.with the 12 volt panels?

The problem is that 42Voc (recently also seen as being 45v) limit of the controller.

Two of those 100w panels with 22Voc each in series as a "24v" array maxes out the controller. If you go over that Voc limit it fries, no second chance! In parallel as a "12v" array, the controller has little extra voltage to buck more amps from but as least it would work.

I have that controller ($102) so the panels in that kit are $198 for the pair.

I'm looking at something like this:

http://www.eco-worthy.com/catalog/mppt-series-complete-200w2100w-grid-systems-with-mppt-controller-p-325.html

??? Will the 20a mppt work o.k.with the 12 volt panels?

It helps to be spry in your 70s. Some guys where we usually camp are not, so I get to scamper up on their roofs for them :)

Exactly, BFL... not a permanent installation, but one with options! I guess it all comes down to how much solar one needs, and/or how much energy one is capable of, or willing to put into set-up and tear-down.

westend wrote:
I was thinking of using the diversion power feature to heat the water in my steel water tank when camping in cold weather. The steel tank is under s dinette seat/convertible bed and could supply some heat exchange in that area. Really, it is all about using excess harvest and being able to store it, either as electrical energy as we do with batteries or as heat through an element. I've forgotten what the diversion circuit of the little Morningstar 15 will handle but I'm pretty sure it is not 15 amps. I'll check on that.

You're basically suggesting using the extra power for hydronic (hot water) heating; and that's the first thing I would try to use it for. There's no need to limit the hot water to that tank, either. You could run 5/8" heater hose to other areas needing additional heat. You just connect the hoses to short lengths of finned copper pipe heating elements, and add a small, low draw 12v pump.

One caveat is, how much "extra" power can one really harvest in the colder/darker months? The other is, the hwh must be hybrid.

jrnymn7 wrote:
Snowman wrote:

"Now I'm going to add roof panels as the next step. But since I like shade, I expect to have to supplement with the portables when we camp in the summer. "

Moreover, the portables are far better for sun tracking during fall, winter and spring, as well. And, frankly, who wants to have to clean snow off the roof for power? It seems to me portables have more pros than cons, while roof mounting has many limitations.

In the end, if I ever get tired of having superior tracking ability, and therefore increased efficiency, I can always roof mount them. :)

I made a tray for my 130w panel that I could leave on the roof (connected down through the fridge vent)

I could leave it as shown for travelling, leave it flat or propped up on the roof while stopped and nobody could steal it, or take it down and set it up on the ground just propped up or in a contraption for manual tracking. Max flex.

Don't they have elements for converting a propane hwh to electric, or both gas and electric?

Snowman wrote:

"Now I'm going to add roof panels as the next step. But since I like shade, I expect to have to supplement with the portables when we camp in the summer. "

Moreover, the portables are far better for sun tracking during fall, winter and spring, as well. And, frankly, who wants to have to clean snow off the roof for power? It seems to me portables have more pros than cons, while roof mounting has many limitations.

In the end, if I ever get tired of having superior tracking ability, and therefore increased efficiency, I can always roof mount them. :)