Solar Power Roofing Materials

roofAll it takes is a few minutes on a Texas roof in the summer to realize just how much wasted energy is bombarding your house every day that not only are we not taking advantage of; we are actually fighting against it in the summer. A lot of energy is spent defeating the natural warming of the building with air conditioning when we could be using it to work for us.

I have a friend who is working towards pulling his farm house completely off the grid; solar power, wind power, geothermal heat pump…. He doesn’t so much love the planet as hate the electric company — but whatever works. And it will work since he lives out in the middle of nowhere. But try putting in a bunch of solar panels and a small wind farm in a neighborhood with a homeowners association and the legal battle is going to make the news (why you will never catch me buying a house in that kind of neighborhood).

So the way to go if you want to go green and still stay under the radar is photovoltaic shingles. Each of these 12 x 86 inch panels replaces the traditional shingles on the roof, and each one is a photovoltaic solar cell producing electricity to power the building they are attached to. The modern solar cell has been around since the 40’s; photons in the light hit the solar panel and are absorbed by the semiconductor which in turn knocks loose electrons allowing producing an electric current. Then typically the DC current produced by the panels is run through and inverter to create the AC power that most houses use. Excess power is routed back out through the meter and back into the grid for which the homeowners is credited (there are exceptions) by the power company. Ideally this makes up for the power used at night that comes in from the power company. Alternately, like in my friend’s plan the DC power charges a battery bank then goes to run the house day and night.

Now these panels are more expensive than traditional solar panels (which is partially offset by the fact that you have to have to pay for shingles anyway) and most houses are not going to have enough surface area available on the roof to completely power the entire house. According to this article by Technology Review:

Around 500 square feet of PV tiles can produce three kilowatts of electricity, according to Subhendu Guha, president and chief operating officer of United Solar Ovonic, a maker of PV shingles in Auburn Hills, MI — and most roofs are several times that size.

“A south-facing roof on a three-bedroom home could supply 20 to 30 percent of the home’s electrical needs,” says Paul Maycock, a consultant and head of PV Energy Systems in Williamsburg, VA.

 

So couple the solar shingles with other energy saving design ideas such as geothermal heat pumps and efficient lighting and appliances and you can probably provide a significant part of your homes energy directly from the sun. And without all those pesky injunctions and court dates.