OCT 08

10% isn't the greatest efficiency... but the key here is going to be cost. If they can cost (with installation) near the price of roofing shingles, then it becomes worthwhile to use these instead of traditional shingles. On the other hand, if they cost quite a bit more than traditional shingles, there's not a lot of point, given the low efficiency.

"The advantages to these solar panels go beyond aesthetics - they can be installed by a regular roofing contractor..."

Wow, these shingles must automatically convert DC to AC, automatically install conduit, AC & DC disconnects, automatically install the inverter, and self-connect to your home's electrical service panel and the Grid! Hot stuff!

And, without any solar training by "a regular roofing contractor", can they be used all over the roof including in the shade and facing North (in Northern hemisphere)?

So, let's see. Just over 1/2 as efficient as traditional mono crystalline solar panels, installed by people who don't have a clue about solar irradiation or shading issues, and with a proven track record of ___ days?

We've already seen ads in our area by a large roofing company that shows a thin-film laminate solar roof that has a huge chimney shading about 1/3 of the array. Anyone bother to tell the homeowners that the shading with effectively kill ALL the output of their beautiful new system?

I've always thought it would be neat to have solar panels on my roof, but I've also heard recently about "green roofs" where grass and shrubs and such are grown on top of a roof.

**Would solar panels actually be more environmentally friendly than a green roof?

I would like to see someone write an article discussing the energy savings due to roof mounted pv modules installed on a traditional rack versus thin-film and BIPV installations. Think about how hot your attic gets, and then how much heat is then transferred into both your home and through the duct work. The traditional method of installing pv creates an umbrella on the part of your roof that receives the most sun exposure.

So in short, modules installed on racking are approximately twice as efficient, therefor producing 2x more energy on the same foot print, and prevents the need to run your air conditioner as much. In sub-tropical and tropical locations the A/C is by far the biggest energy hog.

If anyone has read an article on this please email me at This e-mail address is being protected from spambots. You need JavaScript enabled to view it '> This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Why is it that some peepz just gots ta bring da hate to every article on this blog? You don't like it, start ur own Fortune 500 company, foo.

So doing a little reality checking is bringing on 'da hate'?

We keep seeing promises and re-hashing of technologies that have been around for years. So the former maker of Napalm has "invented" solar shingles... NOT.

They've been around for years and years, and are not in widespread use for good, solid reasons; a few of which were in my post. There are others, too, if you care to pull your head out of ___ ___. (fill in the blanks any way you like.)

These panels look like they get really hot in the sun. I wonder if you could get some water pipes in there to take advantage of the radiant heat from the panels to use in the home hot water heater.

I looked into similar shingles, but went with regular PV panels because of 1. Heat into the attic, and 2. Cost. I had been worried about the look, because the front of my house faces south, but I actually really like how they stand out and provide an advertisement to my neighbors. More options are always better, but I don't know if these will be a great change or just a little one.

And while the install of the shingle can be done by any roofer - I doubt they're trying to say that the roofing company can hook up the inverter and everything else as well. I would think the city inspectors would put a stop to that.

Very interesting! It's great to see more companies trying to go green. I hope they install a geothermal system some day! They work great and are very eco-friendly.

For Jeff

combined photovoltaic and hot water panels have been around a while. Basically the PV panel has a water jacket on its' back side connected into a regular water heating system. You get a double benefit; not only do you get some heating for your domestic water, the resulting temperature decrease on the PV part of the panel also increases it's efficiency. However proper system design is necesary to maximize these efects.

Yeah I am aware of the hybrid pv/hot water systems (never installed them but have done plenty of research). This is a great idea because the water cooled pv cells will operate at a higher efficiency in theory, because they will have a lower temperature. In warmer climates there is not a need for that much btu transfer to water in most cases. This design would work well in cold climates when the hot water can be stored and used in radiant floor heating.

However heading back to my original point... in warm-hot climates where thin-film pv has been installed on a residential roof, it is my guess that 95%-99% will NOT have a hybrid hot water system that benefits in other energy savings. Therefor the heat is transfered in the attic and causes the ac to run more often to remove the heat from the living space. I have searched FSEC and other sources and have been unsuccessful in find a study performed on this issue.

I am hoping someone else has had better luck than myself in finding a study on the negative effects of thin-film on a homes cooling effort.

Jeff

I did find something that addresses the issue. Energy Conversion Devices presented a study on their BIPV products at the National Solar Energy Conference in 2004.

I will let you read it for yourself if you are interested: http://www.coolrmetal.com/docu...ltaics.pdf

Most of the study builds the case for a negligible difference in the heat transfered to the home, but the case study was using a home that had a well insulated R30 barrier on the backside of the roof sheathing. However below is an excerpt that applies to most the old homes in my neck of the woods, Key West, FL.

pg 4 of 6

3. BAD SCIENCE DISCLAIMERS
In the previous section I showed that heat from the a-Si BIPV roof would negligibly impact the energy use in your home. However, this would not be true in homes that are not consistent with our set of assumptions. For example, let us assume you have little or no roof insulation (R-2 instead of R-30); let us further assume you have a relatively inefficient air conditioning system with a COP of 2 rather than 3.5. In such a case all the PV power would be needed to pump the heat from the roof out of the house. Things would be even worse if you have leaky air conditioning ducts in the hot attic.

I would love to see Home Power Magazine, or another credible source, pick this up and run with it. Better yet research performed by NREL or FSEC would be great.

This is a huge step up from the traditional Solar Panels. Although some people enjoy showing off their Go Green houses. However the cost saving will be incredible because any licensed contractor will be able to install them. While I am sure the solar panels themselves are expensive, at least the long-term prices will be low. Great article.

Please either moderate these comments or exclude posts from ugg boots, nini, ugg boots uk sale etc. ad nauseum. They detract from sincere attempts ot comment on the facts, views, potential, science, impact, politics, economics, geekness of the article.

Thanks in advance for cleaning up the commercial trash.

We got solar panels installed in early Sept and they look fine. You hardly even notice them from teh street. Between the panels and our concerted effort to reduce electrical use (unplugging, changing light bulbs, using power strips to eliminate phantom usage,etc.), our electric bill this past month was less than HALF that on last year. AMAZING!

I was thinking a hybrid system would be more efficient if there was a way to raise it a foot off of the roof in summer, so that it shaded the house with an airspace between, perhaps creatively 'dyson' ducted to create airflow - and then sit it back on the roof to transfer heat into the house in the winter when you want it.

I'm not an engineer by training but I dream of being a part of THE MIGHTY INVENTION that saves the world. This site is a window to that dream. Revolutionary ingenuity like the Windbelt or the Watercone (www.watercone.com/product.html) inspire me. Great to feel there is a big circle of like minds.

Hi everybody!