Types of Photovoltaic Solar Panels
3 of 5 in Series: The Essentials of Photovoltaic Solar Power for Your Home
If you're looking into powering your home with solar power, you need to know about photovoltaic (PV) panels. PV panels, which cost anywhere from $2.40 per watt to over $5 per watt, are the single biggest expense of a PV system. Their placement and mounting affect your system performance more than any other facet of the job.
Different types of panels are finding their way onto the market. The configurations of these different types of panels (how they're combined physically) govern how much space they take:
Rectangular: The most common type of panel is a rectangular, aluminum-framed complex of individual solar cells.
Triangular: Triangular configurations can match the contour of your roof and offer a pleasing, symmetrical appearance from street level. Expect to pay more for these.
Integrated: These can be mounted directly over tiled roofs, and they match the undulating surface, making them great for Spanish-style roof. Expect to pay a lot more for these. You can also "integrate" panels directly into your existing roof, matching the roof's tile shape and size. These are expensive, but they look good.
Flexible: These panels come like a big roll of tape and can be installed on flat roofs very easily. This type of panel is not as efficient, so it takes up more roof space per watt, but the price per watt is lower.
Many customers are concerned with a panel's efficiency, which is the ratio of power output to square footage. The fact is, efficient panels usually cost more per watt, and if you have enough roof space, you don't need to maximize panel efficiency. If you're pinched for roof space, you may need to invest the extra money for efficient panels.
Here are some other concerns when choosing your panels:
Warranties: Most PV panels are warranted for 25 years, but beware; panels degrade over time (just like everything else, they wear out). System warranties specify a percentage of original power output over time, say 80 percent after 25 years. Over time, your system puts out less and less energy; it's inevitable.
Manufacturers: Stick with a reputable manufacturer that can document a proven track record. Check the quality of panels by reviewing information on the Internet.
Panel maintenance: Many new customers feel the need to clean their panels, but it's usually not worth the work, which can be difficult and dangerous, especially if they're mounted on the roof. If the panels are ground mounted, cleaning them is usually easy. Simply hosing the panels off with water is fine, unless you have well water, because the sediments calcify on the panel face, and over time a layer of crud builds up and affects your system performance. Plus the layer of crud is extremely difficult to get off and it looks cruddy.
Don't rub the panels with an abrasive brush or sponge. You'll scratch the surface, and this will result in degraded performance. The coatings on panels are extremely important; they ensure long lifetimes and good performance.