It all begins with the module. The solar panel, or “module,” converts the photon energy of sunlight into potential electrical energy “voltage.” Hence the term “photovoltaic.” There are many different ways to accomplish this energy conversion and each process results in a different type of module that has certain strengths, and sometimes weaknesses, in a given operating condition. Some methods yield greater efficiency in extreme heat, some are more efficient by unit area, some do better in partial shading than others, some have important aesthetic differences and some lend themselves well to unique mounting solutions.
Decision Factors - Let Customer Preference Guide You
The customer’s preferences are the most important. Do they want low profile, black frames, building integrated, a large amount of solar in a small space? These preferences will define the family of products from which you can choose.
The Right Module is More Important than Cost
The cost of a solar panel is determined in part by the size (in Watts), the rated efficiency, the manufacturer and the style (i.e. building integrated or framed). Choosing a solarpanel simply because it is less expensive is not wise. It may not fit the install situation, customer preferences or requirements for a local rebate. It is always best to choose the right module and try to get the best price available for that module.
Durability / Warranty
All DC Power Systems modules have a 20 or 25 year warranty. Anything less than 20 years should not be considered. Despite warranties, the life expectancy of most solar modules is 50 years or more.
Cell Type
There are 3 main types of solar cells. Monocrystalline silicon is the most efficient and produces the smallest panels for a given watt rating. Poly-crystalline (or multi-crystalline) silicon produces the next most efficient type of cells and are a popular choice. Amorphous (or thin-film) silicon uses the least amount of silicon and also produces the least efficient solar cells. This means a thin film system takes up more area than the other two.
Size and Watts
Solar panels are usually priced in dollars per watt. Larger panels typically generate more watts when compared to other modules of similar technology. Expect to pay twice as much for a 200 Watt panel, compared to a similar 100 Watt panel. The type of solar cells used in its production also determines the size of the solar panel. More efficient mono-crystalline solar modules are typically smaller than poly-crystalline modules of the same wattage. While thinfilm panels are quite a bit cheaper than mono-crystalline and poly-crystalline, they require roughly twice as much space per watt as the more efficient crystalline technology.
Module Type
Most solar modules sold today are traditional framed crystalline cells. Sometimes however, building integrated
photovoltaics (BIPV) are more appropriate or desired. Building integrated modules, like framed modules,
are available with all three primary cell types. Building integrated modules typically replace other building
components such as concrete roofing tiles with solar roofing tiles or regular glass with solar glass.