Solar Panel Construction – Module Type and Power Output
Solar panel construction lies at the heart of every solar power system. Also known as the photovoltaic (PV) module, the solar panel is usually square or rectangular in shape, and is where all the magic begins. Without this collector of solar energy, nothing happens. These can be hooked in parallel or used singularly, and come in the form of roof-mounted shingles, a standing-seam roof panel or ground-mounted array. However, one constant exists in all panels, regardless of shape or size, the most effective solar panels are made of silicon.
Here's an excellent nuts and bolts description about solar panel construction:
But while solar panels are the most necessary of all solar components, they are not the smallest or most basic. Solar panel construction actually begins with a much smaller component. That is the 0.5 volt-producing solar cell, which operates with other solar cells in a solar panel to produce different levels of voltage, most commonly 16 to 17 or 32 to 34 volts.
Keep in mind that as much as 80% of your investment will lie in the PV modules themselves, and there are literally hundreds of types available, but rest easy. PV solar panel construction quality is universally exemplary. You can usually get a 20 to 25 year warranty and easily expect at least that many years of trouble free life. However, you may have to shop around to find any, because with the popularity of solar power has tightened inventory levels. Online purchase from a reputable manufacturer will solve this problem.
So no matter what brand you choose, the quality will be high, and the price about the same per volt, so remember that bigger is generally better. PV modules are rated by a strict testing procedure which shows how many watts they produce. When you purchase a higher wattage module, you skip all the wiring and connecting in parallel that is required with several smaller units. The more common modules come in 150 to 250 watt sizes, but there are a few things you need to consider when making your PV module choice.
You have to choose between single crystal or polycrystalline modules or amorphous silicon modules. Amorphous modules work marginally better in areas of low light and fewer sunlight hours available and lose less voltage at higher temperatures than polycrystalline modules, but are usually 30 to 50 per cent larger.
With single crystal or polycrystalline modules, you will get more power per square inch, roughly 10 to 12 watts of energy output per square foot of module area. When you factor in the average U.S. amount of collectable sun per day of 5 hours, each square foot of solar panel construction will yield an average of 50 watt-hours of usable energy.
Solar panel construction also differs between the two types of PV modules. Polycrystalline modules usually have aluminum frames and tempered glass top covers. These are the most efficient, delivering the most watts per sq foot. Amorphous silicon modules require up to 50 percent as much surface area to deliver the same power, as mentioned above, but can be made of materials other than glass, rendering them unbreakable.
The Uni-Solar corporation has a line of amorphous modules that actually become the roof, rather than sitting on top of it. Their “peel and stick” models apply directly to commercial membranes or standing seam metal roof pans, and if you can attach to the pan before it is installed, they are much easier to handle and install. These versatile modules are thief and hurricane-proof, and the tossed rock from the neighborhood hooligans bounces harmlessly away. There is no increased cost of installation for all these benefits, only the size issue.
There have more recently even been some manufacturers that have harnessed the awesome heat-collecting properties of ceramic tiles and weaved cutting-edge PV modules into them for more attractive, less obtrusive brown and orange designs that are aesthetically appealing.
Solar panel construction is generally universal when it comes to mounting the panels. Extruded aluminum mounting rails come in different pre-cut lengths with multi-position slots to accept any number of module sizes and rafter and joist spans. Leg hardware is then added as it is needed.
Roof attachment is usually accomplished with roof-penetrating waterproofed standoffs with protective flashing that every roofing contractor understands, should you decide to employ professionals for installation. The common asphalt shingle makes the expensive standoffs optional, and solar panel construction skips this worry altogether when you employ ground-mounted systems that use the same mounting rails, but use built-up legs of pipe or other materials.
Below we have provided you with some common PV modules currently on the market along with their sizes and energy outputs.
Single or Polycrystalline Modules
Product and Wattage
BP 160 or 170 watts
62.7 x 31.1” = 13.5 sq. ft.
Evergreen Spruce-Series 190 watts
61.8” x 37.5” = 16.1 sq. ft.
Kyocera 167 watts
50.8” x 39” = 13.7 sq. ft.
Sharp 216 watts
64.6” x 39.1 = 17.5 sq. ft.
Shell PowerMax Ultra 165 or 175 watts
64” x 32” = 14.2 sq. ft.
Product and Wattage
Uni-solar PVL-series 13.6 watts
216” x 15.5” = 23.25 sq. ft.
A short introduction to Solar Photovoltaic energy generation whci is pretty good considering how short it is (about 2 1/2 minutes)