The use of solar cell technology in making photovoltaic roof shingles is considered to be a drastic breakthrough in harnessing the power of sun. Ongoing research suggests that in future we can expect solar power systems that are even smaller and more practical.
In the 1970s when the idea of tapping solar energy for home use surfaced with the introduction of solar panels it involved mounting panels the size of a table tennis table on roofs. The last five years have however seen the industry becoming more architecturally savvy. Advances in technology have given photovoltaic power systems a complete makeover. In fact, the renewed popularity of solar energy is attributed mostly to aesthetics.
Photovoltaic roof shingles look almost like regular roof tiles and are among the most recent additions in solar energy collections. They blend with conventional roofing materials, look like asphalt roof tiles and at the same time provide all the benefits of regular solar panels.
The most recent development in photovoltaic roof shingles has been the advent of thin film panels. Since these use less of materials like silicon and other heavy metals, photovoltaic roof shingles made by using this technology are lighter, less expensive, easy to install and require less additional framework for support.
Photovoltaic roof shingles fall under building integrated photovoltaic systems that combine solar cells with slate, fiber-cement and asphalt roofing. Electricity is generated when sunshine strikes the semiconductor layer, typically crystalline silicon laminated to the shingle’s surface. A single shingle may generate only 15 to 50 watts of electricity but hundreds of photovoltaic roof shingles can generate enough of it to power a whole house. Building integrated photovoltaic systems, including transparent and translucent photovoltaic systems are used for facades, glazing and flat roofs for powering big buildings as well.
Choosing to install photovoltaic roof shingles in your home does not necessarily mean cutting off ties with your existing power utility. The system can work in concert with the existing power lines. If your photovoltaic roof shingles produce more energy than you can use, most states allow you to sell back the unused electricity back to the power utility for a credit. Generation of excess power is common in states like California and Arizona that get a lot of sunshine during the year. After sundown or on rainy days, if you are short on power, the existing power lines kick back into service.
A general guideline is 1 kilowatt or 1,000 watts per 1,000 square feet of house area. The increased cost can be rolled into the mortgage and on an estimate; a 2-kilowatt system entails an extra $100 in monthly mortgage installment. However, when it is tax time, the Energy Policy Act of 2005 allows you a generous tax break for having installed environment friendly photovoltaic roof shingles. You can get 30% or up to $2,000 as tax rebate.
The bottom line is that installing photovoltaic roof shingles means you need not worry about the rising energy costs any longer and the money you save pays for the initial cost.