PV shingles instead of roof-mounted panels? (total newbie question, btw)

[Witold Gintowt]

Hello All.

A self-declared total newbie, I am interested in what information and/or impressions you can share about building-integrated PV shingles (the likes of DOW Powerhouse (http://www.dowsolar.com/index.htm) or Luma Resources (http://www.lumaresources.com/datasheets/lrss.pdf)):
- How do they compare to roof-mounted panels?
- Who installs them in Madawaska Valley (Ontario) area?

Background:
The roof on our cottage (ca. 35° slope, south/north), is just about ready to be replaced. Unless strong reasons exist to the contrary, I am hoping to replace the entire south side of the roof with grid-tied PV shingles (microFIT).

[Rob Beckers]

Hi Witold,

Welcome to the forum!

A few remarks, very much in general as I've never personally installed those shingles: I'm aware of two types being used; regular crystalline silicon, and thin-film. Both should work as well as the more familiar rectangular modules, however, being part of the roof surface (and unless the roof underneath is vented really well) they will get sti#%in' hot. PV produces less as it gets warmer, so you'll loose some over regular panels mounted 3" or more off the roof deck (which sets up a chimney effect, keeping relatively cool air flowing underneath). With that in mind, thin-film type shingles will do better than crystalline silicon, having about half the temperature coefficient. The downside is that thin-film is about half as efficient as crystalline, so you'll need twice the roof area for the same Wattage.

From the financial side; regular PV modules have plummeted in price over the past 12 months. I have no idea if the BIPV products have followed that trend too, it's something to look into. Your payback time depends on price.

I do like the look of the integrated PV shingles, very sleek! I'm just wondering how they compare in performance and price vs. traditional PV. Please let us know if you proceed!

-RoB-

[Russ Bailey]

Rob nailed one problem - roofs are typically hot - panels lose approximately 0.5% output per degree C over 25° C when a roof is 60° or 70° C on a hot summer day is a lot.

Thin film is already not all that efficient - now even less.

Too many connections in the roof as well - each shingle has to be connected I suppose and 100% of those connections need to be made correctly.

[Witold Gintowt]

Too many connections in the roof as well - each shingle has to be connected I suppose and 100% of those connections need to be made correctly.Well, looking at the Luma ones, each "shingle" is actually pretty big (L 54.37 x W 15.62 x H 2 inches). Are you sure this will still fall into the "too many connections" category for a microFIT?

[Russ Bailey]

Well, looking at the Luma ones, each "shingle" is actually pretty big (L 54.37 x W 15.62 x H 2 inches). Are you sure this will still fall into the "too many connections" category for a microFIT?

Using Schuco for an example the 230 watt panel is 65x39 - so about 3 times the connection based on size.

The Luma is not really a shingle but just a special shape of a polycyrstalline panel.

A shingle like Dow has would be approximately 50% the efficiency so double, or more, the connections again.