Seaford   Solar 3755 Oleta Place Seaford, NY 11783 Phone:(917) 860 - 0123 eMail: SeafordSolar@yahoo.com Seaford Solar - Your Simple Source for Solar Electricity

About Solar Electricity: Panels and Systems   [ Go to Page 1 ]  This is Page 2   About PV Systems Types of PV Panels:   The classic approach is to grow silicon crystals, fabricate cells and then mount them in large arrays [see picture, near right→] Crystalline PV panels entered the market in the 1950's, and have a well-deserved reputation for quality and efficiency [8% to 15%].    PV Shingles→   Crystalline PV panels can be either monocrystalline and polycrystalline. Another technology, amorphous silicon is much newer and less efficient [2% to 4%]. Rural consumers might not care about efficiency. Less expensive panels will just take up more room - on the ground. In urban areas, space is usually limited to a rooftop so efficiency is highly critical! Over the long term, both are stable - output drops by 1% or less each year. They are guaranteed to rate at 80% after 20 years and there are PV panels still in use that were installed in the Carter Administration! There are other technologies such as dye-sensitized solar cells [made with layers of titanium dioxide] and other thin-film types [Cadmium Telluride, Indium Diselenide] that are not silicon based. These tend to be much less efficient and production volumes are fairly low at this time. On the other hand, thin-film is light, and flexible. They can be made into panels, shingles, even tents! Iowa Thin Film Technologies "PowerShade" Tent A word about efficiency. On a bright, sunny day, the sun shines approximately 1,000 watts of energy per square meter. Since 1 meter = 3.2808399 feet 1SqM = 10.764 SqFt. a whopping 1,000 watts on a 10.764 SqFt surface. This works out to 92.9W on each ONE square foot. Note that we are given this - as in for free! How much of this do we capture? A 35.3 Pound Kyocera 170 Watt Solar Panel measures (LxWxD): 50.8"x39"x1.4" This is 13.75 SqFt. It generates 170 Watts on across its 13.75 SqFt surface area. This works out to 12.36W/SqFt while the sun gives us 92.9W/SqFt. When you do the math, 12.36 / 92.9W works out to an efficiency of 13.3% Frames and mounts The wolf might try to huff and puff but we don’t want him to blow the roof off your house! Metal frames are permanently mounted onto your roofing beams. The panels clip into these frames these are corrosion resistant and constructed to withstand wind speeds in excess of 125 mph. Typically. these are available in silver or bronze finishes. Other "stuff": Inverters, Grid interconnection, Cables, Switches and Meters [the magic kind that run backwards!] About inverters PV generates DC current - the kind you get out of a battery. On the other hand, Utility grade current is "60 cycle, AC, in phase". An inverter takes what comes off the roof and converts it to Utility grade current. Pretty neat, huh?