The meaning of photovoltaic shingles is evident from the name itself. Photovoltaic (PV) means producing a voltage when exposed to radiant energy (especially light). It is a method of generating electric power by converting the radiation of the sun into direct current electricity with the use of semiconductors that have a photovoltaic effect. Shingles is roof covering consisting of individual overlapping elements. Thus, photovoltaic shingles are solar cells designed to look like traditional asphalt shingles and in common parlance, known as solar shingles.
Most photovoltaic shingles are 12 by 86 inches in size, can be fastened directly to the roofing cloth and when applied have a 5 by 86 inches of exposed surface to capture sunlight. Each brand of shingles has different mounting requirement and some can be intermixed with regular asphalt shingles. Made to look similar to other roofs in most cases makes them a preferred choice of homeowners looking to mix aesthetic value with the ability to utilize solar power without large panels on their roofs.
The first solar shingles that appeared in the market in 2005 were made from silicon, the same material that is used in most solar panels. The latest in photovoltaic shingles is thin-film shingles. These are made from a compound semiconductor material composed of copper, indium, gallium, and selenium, a thin film of which is laminated over the shingles. These match the flexibility of regular shingles but are still in the development stage and less efficient than shingles made from silicon.
Photovoltaic shingles capture sunlight and transform it to energy. Depending upon the brand, each shingle produces between 13 and 63 watts. This translates into a position that if you are using shingles that produce 13 watt, for one kilowatt of potential energy you need 77 tiles to cover roofing area of 100 square feet.
Each solar shingle has 12 inch long lead wires attached to the underside that are pulled through the roof deck when the shingle is installed. After installation, the leads can be extended and installed in a combiner box, from where a single lead is run to an inverter for conversion of direct current (DC) to alternating current (AC) used in homes. Electricity generated by PV shingles can be used in grid-connected or off-grid systems. Grid connected photovoltaic power systems are connected to the utility grid and supplies excess power beyond consumption to the power utility. Off grid systems are use of the grid as a backup source of electricity and the most inexpensive way to install PV shingles.
Using photovoltaic shingles is a great idea that combines the functionality of solar panels and the appearance of shingles. They can be integrated to the exterior design of your home. If installed correctly they can withstand high winds and cover larger areas as compared to traditional solar panels. You can even qualify for tax benefits. New designs of photovoltaic shingles can be installed in less than half the time it takes to install traditional solar panels resulting in reduction in the cost of installation.