Photovoltaic Solar Panels
The photovoltaic (PV) solar panel or solar module, is the device that converters sunlight into electrical power. Solar panels are made in several ways, from a variety of materials. Of course each panel type has it's advantages and disadvantages.
Polycrystalline Solar Panel
A polycrystalline solar panel is made from a block of silicon cells that has multiple crystals. These panels often have a surface that looks somewhat like a blue mosaic due to the different crystals that make up a module. Polycrystalline solar modules tend to be less efficient than those made from a single crystal. They are easier to produce and cost a little less to manufacture. Durability and longevity are comparable to monocrystalline modules.
Common brands of panels made up of polycrystalline modules have about a 14% conversion efficiency. That means 14% of the energy in the sunlight that strikes these panels is converted into electricity. A square meter of panel exposed to full, direct sunlight will produce around 140 watts of power, at 25 degrees Celsius (about seventy-seven degrees Fahrenheit). Panels operating at a higher temperature – fifty degrees Celsius or more – will be a lot less efficient. Note that the efficiency of a solar panel will not impact the power output. Both a Poly and a Mono solar panel rated at 200 watts, produces 200 watts - but a solar panel with a high efficiency rating will have a slightly smaller footprint. This may be worth considering when your space is very limited. However, if you have the room to spare, then the efficiency should not be a factor in your purchase decision.
When working with a solar power system you should take temperature into account when working out their costs and ROI. As the temperature goes up, the power output goes down with Poly and Mono solar panels.
Monocrystalline Solar Panel
A monocrystalline solar panel module is made from a block of silicon cells that has a single layer of crystals. These panels often have a surface that looks black or very dark and smooth. Monocrystalline modules have about a 16% conversion efficiency.
Monocrystalline solar modules also experience a reduction in output as the temperature from the sunlight increases. However, this reduction in output is usually less than that experienced by polycrystalline cells.
While mono solar cells are more fragile than poly solar panels, both types should last for 40 years. Standard warranties for both types of solar panel, include a manufactures warranty on workmanship for 5 years. And production warranties for 25 years - after 25 years the panels should still produce at least 80% of their rated value.
Thin Film Solar Panel
Thin Film solar panels are also called amorphous silicon photovoltaic cells and tend to be flexible, not rigid like Poly or Mono panels. They are made of a silicon material placed between flexible laminate, steel or glass.
Thin film solar panels, made with a flexible laminate have been used as a type of roofing material. Unlike rigid panel types, they don’t stand out, blending in with the roof itself. They can actually be used instead of shingles for roofing, creating an entire roof that generates power from sunlight.
Thin Film panels however, are not as efficient, with about a six percent conversion rate for energy drawn from the sun, thus they take up more than twice as much installation space for the same amount of power. They do cost less per watt, however. Their thinner structure needs less material, allowing for cheaper panels to be produced.
One benefit of thin film solar panels that other types can’t offer is that they don’t suffer a decrease in output when temperatures go up. Some may even have a slight increase in their outputs. Because of this, thin film solar panels often have an actual output that’s very close to the one they’re rated for.