Solar Elec?

[donheff]

I read an article in New Scientist today about some photoelectric breakthroughs that may drastically alter the financials over the next decade. Apparently with current silicon technologies one photon can release no more than one electron. Now using nanocrystals of various substances, scientists are getting up to 7 free electrons from one photon. If the engineers can get the concepts sorted out in the real world we could get much cheaper photo electric and, potentially, a cheap source of fuels (hydrogen for fuel cells and, possibly, ethanol and methanol).

 

[Brat]

Nords, now you are talking my baby's language!!!  She and her spouse are CPAs, they intend to live in this home for the rest of their lives.  When DH has a couple quotes he can lay down the numbers and let them push them around.  

My gut says that the smart move is to design in conduit for wiring to accomodate a system.  I agree with donheff and others that more efficient systems will soon be on the market and material prices will fall.  Give them ~5 years in the house to pay down the mortgage, then install solar electric.

I forsee solar units that look like shingles or slate tiles that don't take a crane to place on the roof.

 

[cute fuzzy bunny]

Already there...a number of companies make solar units that look like roofing materials...except all the ones i've seen are black, so if you roof isnt black, you're SOL. Maybe someones making other colors by now.

 

[Brat]

Already there...a number of companies make solar units that look like roofing materials...except all the ones i've seen are black, so if you roof isnt black, you're SOL.

Black will do just fine, particularly because they will be on the back side of the house and wouldn't need to match the front (DH might gag however).  The ones I found on the web indicate back orders through 2007!!

 

[Nords]

I read an article in New Scientist today about some photoelectric breakthroughs that may drastically alter the financials over the next decade. Apparently with current silicon technologies one photon can release no more than one electron. Now using nanocrystals of various substances, scientists are getting up to 7 free electrons from one photon. If the engineers can get the concepts sorted out in the real world we could get much cheaper photo electric and, potentially, a cheap source of fuels (hydrogen for fuel cells and, possibly, ethanol and methanol).

Remember how long it took to get from the IBM PC to the iPod? I think that's roughly the length of time it'll take for this technology to become an affordable consumer commodity.

My gut says that the smart move is to design in conduit for wiring to accomodate a system.  I agree with donheff and others that more efficient systems will soon be on the market and material prices will fall.  Give them ~5 years in the house to pay down the mortgage, then install solar electric.

Well, one of the barriers to consumer rooftop solar is that it only pays off if you stay in the house for a while-- which is a lot longer than the seven years that most homeowners stay put. And no homebuyer will pay extra for the array.

I forsee solar units that look like shingles or slate tiles that don't take a crane to place on the roof.

Ovonics came out with solar roof tiles 10 years ago. Their latest product just popped up a few miles up the road this morning in our local newspaper:
http://starbulletin.com/2006/05/26/news/story04.html

 

[Brat]

Remember how long it took to get from the IBM PC to the iPod?  I think that's roughly the length of time it'll take for this technology to become an affordable consumer commodity.
Well, one of the barriers to consumer rooftop solar is that it only pays off if you stay in the house for a while-- which is a lot longer than the seven years that most homeowners stay put.  And no homebuyer will pay extra for the array.
Ovonics came out with solar roof tiles 10 years ago.  Their latest product just popped up a few miles up the road this morning in our local newspaper:
http://starbulletin.com/2006/05/26/news/story04.html

My DH shot down my desire for solar roof tiles last night.. he said that roofing is too important to trust to solar tiles. He believes that a system that is supported on a frame above the roofing is wiser. Solar units on a frame are easier to replace/upgrade.

 

[cute fuzzy bunny]

Depending on your roofing material, you might find the opposite to be the case. In my case, using concrete tiles, the solar panels are a direct replacement for the tile and replacing/upgrading one is as simple as lifting the tile above it, picking it up, and putting a new one down.

In fact, concrete tiles can 'pass' as much as 15-20% of the water that runs over them once they become saturated, leaving the tar paper to do the dirty work. I'd imagine the plastic and metal of the tile are a little more water resistant.

Solar unit on a frame require holes drilled in the roof to mount and put a good deal of weight on a smaller square footage area. And might have to be removed to do any roof repairs underneath. Holes in the roof and heavy stuff putting pressure on the sheeting are both leaks waiting to happen. Good silicone sealer and the wait might be a long time.

Now if you're doing asphalt shingles...I dont think you have an option to use a fake shingle.

 

[Brat]

The roof is yet to be designed so loading awaits that detail. I asked him the same question about a frame on the roof and he reminded me that it is all in the flashing. The same is true of plumbing vents and chimneys. I think he has standing seam metal in mind for under a solar array (which would face away from the street). That should handle any flex in the underlayment due to wind catching the panels (like a sail) and leaves/needles should sluce under the array easily .

 

[Nords]

My DH shot down my desire for solar roof tiles last night.. he said that roofing is too important to trust to solar tiles.  He believes that a system that is supported on a frame above the roofing is wiser.  Solar units on a frame are easier to replace/upgrade.

Tell your spouse from me that he's a killjoy!

I think a standing-seam metal roof is the best roof around if it's put together by experienced contractors. (And yup, flashing will make or break the roof.) If the choice was (1) solar tiles or (2) composition shingles or (3) tiles or (4) wood shakes then I'd go solar. But if you're putting in metal then that's probably better than solar.

Talk to a solar firm and a roofing contractor before you make that standing-seam decision. There may be an easy way to add rack mounts to the roof installation that don't involve drilling additional holes. That'll greatly simplify the rack installation later.

While framed solar units are easier to upgrade, I don't know anybody who upgrades. People get rid of their systems, people replace broken gear, or people expand their systems. There's absolutely no benefit, financial or otherwise, to replace a perfectly good solar panel with one that's a little bit better. (The labor only makes it more painful.) Ovonics has a good niche product that's reliable and as cheap as they're likely to get for some time... so I wouldn't hesitate to put solar tiles on a roof if it seems attractive. There are many cheaper ways to go but I defer to décor issues.