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

Snowman9000 wrote:
Here's an offer I got accepted last night on ebay. $65 asking price, $58.00 best offer, accepted, for this Morningstar 25A SunSaver Duo PWM controller with remote temp capability. Needs an optional temp wire to do that.
Says it is for 2 battery banks, but it will work normally with just 1. I confirmed that with MS.

Free shipping to USA. I think it's a very good deal.

Solar Blvd: MS Sunsaver Duo on ebay

You can use those duos to put on the house and starting battery of a MH. Be able to switch off the engine side IMO so it doesn't overcharge when the house side is being cycled.

Snowman9000 wrote:


Jim, I'm wondering if your mono-poly results simply reflect one bad mono panel?

I had heard that suggested before and had excepted it as a possibility until I got the pair of 245w monos and they showed the same caricaturists.

I had no controller for the first year that I had my panels, so I would drag them out to the yard in all kinds of weather. I'm not a highly techy person so all I had was a handful of meters and would record the Voc and Isc. When temperature was being discussed, I taped a thermometer to the back of the panels and kept track of that too.

These are just my unscientific observations.

The monos in bright light reach a higher Voc than the poly does. On a cold winter day the 220w went over 40v for a few minutes and then settled down to a working Voc of 38v. Those extra volts only translated to 3/4 of a amp additional output. Drop the light level and the Voc drops quickly and can get down into the 20's where there isn't enough for the controller to do much.

The poly is more consistent with it's Voc. It usually runs around 34v, maybe 35v and when the light drops, it stays above 30v. The 230w poly is noticeably bigger than the 220w mono and slightly bigger than the 245w mono.

I may as well for reference add that amorphous panels have the largest foot print and the best ability to collect power in low light.

So the monos are tuned to bright light and almost treat low light like its not worth the effort. Polys are the middle of the road, needing a bigger footprint than monos in bright light, yet can't collect as much as amorphous in low light.

So if you are in Arizona where the sun is intense...Mono.

In Sunny Colorado where the pattern has been morning sun and afternoon clouds...Poly

In the PNW I'd see if I couldn't get enough amorphous panels up there to cover my needs.



Last thing is I would have never known there was a difference without spending the time with the meters on the different panels. I would have looked at the drop in power on the monos and thought "well it's cloudy stupid, what did you expect"

Again, just my unscientific observations, nothing to base your personal decision on. Even weirder is I believe different controllers have sweet spots with Voc and matching up the right controller to my panels will get me more. (now you know why it's taken this long to mount. lol)

Here's an offer I got accepted last night on ebay. $65 asking price, $58.00 best offer, accepted, for this Morningstar 25A SunSaver Duo PWM controller with remote temp capability. Needs an optional temp wire to do that.
Says it is for 2 battery banks, but it will work normally with just 1. I confirmed that with MS.

Free shipping to USA. I think it's a very good deal.

Solar Blvd: MS Sunsaver Duo on ebay

Hi RJ,

The original ebay link came up with shipping for me. Perhaps because I live in Canada? It is prudent to check more than one source.

Quote:
Ebay wants shipping--Amazon does not. Therefore Amazon is overall cheaper than Ebay
----------------------------------------------------------------------
What does "free shipping" on the ebay site mean ?

I never found anything cheaper on Amazon.

RJsfishin wrote:
The links above is for Mono panels.
Read JimDenver's post above,...about Mono verses Poly panels before you buy.

3 different brand panels make up my 300 watts. They are all built well, even if a little different frame work. One is lighter than the other 2, but built well. Come to remembering now, the lighter one is maybe the 90 watt, verses 100 for the other 2. But they are all the same physical dementions.
Electronically, they all work great together, even tho some of the specs are different slightly.

My experience is different than JiminDenver. I have mono panels but no poly to compare them to. However, the first spring trip after I installed solar I was getting 3 amps in a snow storm in Rocky Mountain Park. Couldn't be happier with the mono panels.

pianotuna wrote:
Hi mena,

I have that covered with the magic heated carpets that I purchased last January.

Oh yeah, I forgot about those.

Hi mena,

I have that covered with the magic heated carpets that I purchased last January. However, solar output does drop off as the earth progresses into winter. I only have a couple of Winter Solstice readings. One was about 17 amp-hours @ 14 volts--so not a bunch of watts to use.

mena661 wrote:
PT, what about swapping to in-floor electric heat along with 700+W of panels? No propane needed again.

PT, what about swapping to in-floor electric heat along with 700+W of panels? No propane needed again.