Unisolar ePVL 144

jcheil

OK, so I have a friend that has 6 of these Unisolar ePVL 144 panels.
http://www.soldonsun.com/files/UNI-PVL136.pdf

The only reason they have these, and nothing else was because, long story short, they had them hooked up (and a small junk wind turbine also) directly to batteries with no charge or dump controller and their entire cabin burned down when the batteries overcharged and exploded. These were the only things that survived.

That being said, they were way undersized to begin with, had it rigged up and were using them on a 12v system, etc. Just about everything that could be wrong was wrong.

So, they finally want to do things the right way, and will listen to my/our suggestions and based on their daily usage of about 7kwh it is obvious they are in 48v land.

So the question is, is it worth doing anything with these? Obviously they are going to need a lot more panels but I was curious as to if these can be integrated somehow.

Vic

Re: Unisolar ePVL 144

Hi jc..,

Sorry to hear of the fire at your friend's cabin.

As you know, these PVs have a relatively low Vmp, and a relatively high Voc for a 48 V system (which DOES seem to be the correct system V). Two in series is really TOO low Vmp, and three is really too high for most CCs, except a MN Classic 200.

It would be a shame to toss these PVs ... perhaps they could be sold. These are often an OK solution for boat or RV applications due to flexibility, although they have poor utilization of space vs output as you also know.

Just drive-by thoughts, starting over and doing it right is really the best, and these Uni PVs may not work well with the rest of the system design. Would design the rest of the system, and see how these PVs might fit. Good Luck, Vic

jcheil

Re: Unisolar ePVL 144

Vic wrote: »

Would design the rest of the system, and see how these PVs might fit. Good Luck, Vic

That's kinda what I was thinking, but it almost seems like they wouldn't "fit" with any other panels out there, so they would have to go on their own MPPT controller correct? And then, like you said, 2 might be pushing it for a 48v system (perhaps the midnight kidd??) and 3 would need a Classic 200 - which is a lot of $ just to get these panels to play well together with others.

Everyone's thoughts/ideas are appreciated.

Vic

Re: Unisolar ePVL 144

jc ..,

On the surface, a string of three of common 60-cell PVs appear fairly compatible with strings of three of the PVL-136/144. They probably have quite a bit different temperature coefficients of Vmp. Do not have time to study this right now.

Here is a good, inexpensive GT type PV -- Solarworld 265, just as a sample:
http://www.solar-electric.com/solarworld-sunmodule-sw265-monocrystalline-solar-panel.html

This class of GT PV, teamed with strings of three Unis on a Classic 200 MIGHT be OK. It is also possible that it could be best to just sell off the UNIs and move on. Seems that the slope of Vmp vs temperature at different load currents is different for the Uni vs the more traditional PVs. And the mounting approach on the Uni vs AL framed PVs is also different, and so on.

Later, Vic

Cariboocoot

Re: Unisolar ePVL 144

I agree with Vic. Flog 'em and get stuff that will work right for the system.

zoneblue

Re: Unisolar ePVL 144

jcheil wrote: »

OK, so I have a friend that has 6 of these Unisolar ePVL 144 panels.
.. long story short, they had them hooked up (and a small junk wind turbine also) directly to batteries with no charge or dump controller and their entire cabin burned down when the batteries overcharged and exploded.

Without wanting in any way to be disrespectful of your friends ill fortune, do you have any pictures of the burnt system/batterys?

I often say that batterys are worth our considerable respect, sometimes i feel like im being overly melodramatic, but its what comes from my time spent working in the battery bay.

Pictures would greatly reinforce this for newcomers.

jcheil

Re: Unisolar ePVL 144

zoneblue wrote: »

Without wanting in any way to be disrespectful of your friends ill fortune, do you have any pictures of the burnt system/batterys?

I often say that batterys are worth our considerable respect, sometimes i feel like im being overly melodramatic, but its what comes from my time spent working in the battery bay.

Pictures would greatly reinforce this for newcomers.

Yeah I think I did actually take some and I am pretty sure he did. I will have to check my camera later and ask him this weekend.
Sadly, we have a LOT of forest fires (intentionally started) in this area and MANY camps are burnt down yearly.
March 2013 a fire went thru about 1000acres in less than 3 hours (40+mph winds) and we lost 34 camps.

And he agreed with everyone's suggestions and he is going to sell them - Which I was kinda leaning towards to begin with.
Thanks again for the opinions.