opinions on UniSolar flexible PV wanted

thehardway

I have been in my house just a little under a year. It is in VA. zip 24139. ICF walls/SIP roof with corrugated galvalume. My average monthly kwh usage is approx 850 kwh. This is an all electric house. House is currently heated and cooled by a 12000Btu LG ductless heat pump. The majority of our energy usage is hot water heating and clothes washing/drying. (wife and son are at home all day everyday) I am installing an evacuated tube solar thermal collector which should cut hot water energy usage significantly and supplement winter heating through radiant floors. I estimate my average monthly usage to end up around 500-600 Kwh per month. Peak usage should be under 1000kwh per month July/Aug.

I am planning to put a PV system in place on the soon to be built garage. The garage will have a south facing 10:12 pitch roof with standing seam metal roof. The south side will be 38' X 17'.

I happened to run across the Unisolar flexible panels which are made to be used with standing seam roofs. It seems like a pretty quick and easy solution and by my calculations would offset about 50% or so of my anticipated load. Does anyone have an opinion on these? Is it a waste of money? Should I go with conventional panels? I have heard UniSolar is insolvent so how would this affect warranty and replacement issues.

Anybody out there have any experience with these? Given my situation what route would you take?

BB.

Re: opinions on UniSolar flexible PV wanted

I am not a fan of flexible panels--I am not sure you could expect 20+ years from them... Plus Unisolar (as far as I know) is out of business now. No warranty/product support.

One long time poster here (Solar Guppy) loved solar thermal systems--But believes that the "new" heat pump type water heaters are very difficult to beat--especially if you are in a warm climate (they are less efficient if the room falls below ~55 degrees F). They 2-3x more energy efficient than standard "resistance" type water heaters--Plus the provide local cooling and dehumidification (if that is helpful for you).

Solar thermal is lots of plumbing and potential freezing issues... So the ongoing costs/maintenance can be an issue (especially if you have to pay a plumber to fix the system).

Lastly, I would suggest a standard insulated box plus copper pipe on metal collector. The evacuated tube solar collectors are better for very hot water. but interestingly, may not work quite as well in climates with snow... The standard hot water panels leak enough heat to melt off the snow. The evacuated tubes do not and can stay shaded for longer periods of time.

Anyway, my two cents worth.

-Bill

thehardway

Re: opinions on UniSolar flexible PV wanted

BB. wrote: »

One long time poster here (Solar Guppy) loved solar thermal systems--But believes that the "new" heat pump type water heaters are very difficult to beat--especially if you are in a warm climate (they are less efficient if the room falls below ~55 degrees F). They 2-3x more energy efficient than standard "resistance" type water heaters--Plus the provide local cooling and dehumidification (if that is helpful for you).

Solar thermal is lots of plumbing and potential freezing issues... So the ongoing costs/maintenance can be an issue (especially if you have to pay a plumber to fix the system).

Lastly, I would suggest a standard insulated box plus copper pipe on metal collector. The evacuated tube solar collectors are better for very hot water. but interestingly, may not work quite as well in climates with snow... The standard hot water panels leak enough heat to melt off the snow. The evacuated tubes do not and can stay shaded for longer periods of time.

Anyway, my two cents worth.

-Bill

We get very little winter snow and what we do get is usually gone in a day or two. Since I already had the glass and all I had to do was fabricate heat pipes and manifold and all the other radiant plumbing is in place, it seemed like a no brainer.

I have an exterior mechanical building which will house all plumbing/mechanicals so it stays cool in the winter and warm in the summer with no advantage to the cooling benefit as it is unoccupied, not ideal for the heat pump arrangement.

I'm pretty handy with the plumbing and it will be a very short run to collector from storage tank. Biggest investment I have to make is heat exchanger and circulating pump.

niel

Re: opinions on UniSolar flexible PV wanted

i'll agree with bill on all accounts here.

the crystalline pvs today (non-amorphous) will output twice the power for the same area it occupies and why go with a pv that won't last as long? i'm not sure they're in business anymore either so there's a warranty issue.

you can still supplement with solar thermal, but do more reading on it as it does get very involved and is more complicated than you think. i'll recommend you try reading some articles from home power magazine on it. do a search on the net and you'll find it.

peakbagger

Re: opinions on UniSolar flexible PV wanted

I would suggest sitting down putting on your running shoes and run as fast as you can away from unisolar panels. There is no warantee unless some installer wants to warantee themselves and thats only good as long as they stay in business. The adhesives arent forever and when it does fail, its going to leave a major mess on your standing seam roof that is not coming off. They are also less efficient in hot weather as the roof gets quite hot. Regular panels are usually held up from the roof and get some convective air flow to somewhat cool them but if you want cool panels, you need a pole mount setup.

Rick1

Re: opinions on UniSolar flexible PV wanted

How many Sq. Ft. is your house?
Does it have a basement?
Does the Sq. Ft. include the basement?

thehardway

Re: opinions on UniSolar flexible PV wanted

Rick1 wrote: »

How many Sq. Ft. is your house?
Does it have a basement?
Does the Sq. Ft. include the basement?

House is story and a half, insulated slab on grade, no basement. 32X24 first floor and a 16X16 loft room for a total of just over 1000 sq.ft of occupied living space.

Looks like I can cross off UniSolar as you guys have confirmed my suspicions.

I have lots of space, 10 Acres in all so it doesn't have to go on the roof, I just figured that would save some money. The slope and orientation are within a fairly close to optimal from what I can gather. I could easily build a solar shed or do a pole mount system. Lumber is free and I can also do any necessary cutting and welding.

During the fall, winter and spring months I have a decent wind resource though I have not logged it but there is significant flagging of trees and anything that isn't tied down quickly blows away. I think maybe I should optimize my PV for July/August production to meet my summer AC loads and then put up a small turbine to take advantage of the wind. I have about 80' of Rohn 25G lattice tower I could use for mast. I believe it would work well for something like a Bergey XL-1 or a HY1000.

Shadowcatcher

Re: opinions on UniSolar flexible PV wanted

I picked up one of the 140W Unisolar used for $65 including shipping on Ebay and spent two days getting the glue off with mineral spirits. I use it with our teardrop trailer as a roll it out on the beach in the sun supplement to the 185W main panel.
The one part of this equation that has not been discussed is the price. If the price per watt is good enough and with the potential for increased output panels with new technology in the future, there is a balancing act.
The Unisolar panel by the way is rolled up and sits in the tongue box when not needed.

inetdog

Re: opinions on UniSolar flexible PV wanted

Shadowcatcher wrote: »

I use it with our teardrop trailer as a roll it out on the beach in the sun supplement to the 185W main panel.

Have you measured the power output you are getting from it? How does it compare to the nominal 140W figure?

firerescue712

Re: opinions on UniSolar flexible PV wanted

I bought one PVL144 last year off Ebay. It was used and worth the price. The output has been about the same percentage as all the other modules I have. I would not pay new price for one. But for a bargain, it is a good pv module. Like Shadowcatcher stated, it is good for rolling out for supplemental power in remote areas.

ggunn

Re: opinions on UniSolar flexible PV wanted

firerescue712 wrote: »

I bought one PVL144 last year off Ebay. It was used and worth the price. The output has been about the same percentage as all the other modules I have. I would not pay new price for one. But for a bargain, it is a good pv module. Like Shadowcatcher stated, it is good for rolling out for supplemental power in remote areas.

I would worry about fatiguing the PV material from rolling it out and rolling it up. It's not really designed for that.