Solar shingles or solar panels?
By Laura Firszt, Networx
Harnessing the sun’s rays produces a renewable, clean power source which can be converted to electricity by means of solar panels or roof shingles. Here’s a fact sheet on these two methods to help you choose the best one for your home.
* Solar panels are the older of the two, first developed in the 1950s. There are some 40-year-old panels in existence today that are still working at an impressive 80 percent of their original capacity.
* The average solar panel measures 18 square feet and produces 185 to 240 watts.
* Solar panels are typically installed above the shingles or other roof surface, leaving a 6 inch gap. Occasionally this gap becomes home to pests such as squirrels, raccoons, birds and even bats. Special screens are now marketed to protect against animal infestation.
* You can easily position and angle solar panels to catch the sun, no matter which direction your roof faces. Some will even track the sun at various times of day for optimal energy collection.
* It is a simple matter to move and relocate the panels, which may be installed in locations other than the roof – for example, atop a pole or in your garden or yard.
* Solar panels are more suitable for retrofitting if your existing roof is in adequate shape to last as long as the panels themselves, which are typically guaranteed for 25 to 30 years. Minimal – or no – structural change to the roof is required.
* You can save money by installing solar panels yourself; there are kits on the market for this purpose. Be aware, though, that this may disqualify you for subsidies and rebates from the government or utility companies on your solar energy system. Check out the rules for these incentives, as well as your local building code.
Solar Shingles (AKA Solar Roof Tiles)
* Solar shingles were first marketed in 2005. Because they are so new, there is not yet any real life data on how long they last.
* Similar in size and shape to an asphalt shingle, a single solar shingle produces 13 to 63 watts. This type of solar device originally had low conversion efficiency, about half the rate of solar panels. However, with technological advances over the last few years, they have been catching up.
* Solar shingles take the place of their conventional counterparts as the roofing material itself; therefore the ideal time to install them is when you are building a new home or replacing your current roof.
* Lightweight and attractive with a deep indigo blue color, solar shingles have weather resistance, strength and flexibility much the same as asphalt shingles.
* A solar shingle roof is relatively quick to install; the installation time has decreased approximately 60 percent in the past decade to about 10 hours. Nevertheless, considerable technical expertise is still required. As with solar panels, a solar shingle roof must conform to the building code of your state, for example Rhode Island. It is recommended to hire a qualified roofer with experience in this type of installation.
* Solar shingles are difficult to position to take optimum advantage of the sun’s rays, particularly if your roof is not facing south.
* A solar shingle roof will generate heat which the roof substrate must be capable of withstanding. This heat also needs to be directed out of your attic in warmer months.
* Both solar panels and solar shingles should result in substantial savings on electric bills, especially during sunny weather.
* Financial incentives are offered for the installation of either type of system, generally in the form of utility discounts as well as federal tax credits.