If – like most educated consumers – you’re getting multiple quotes for your solar power installation, you’re probably having to compare between various equipment offerings by your solar vendors. Themostprominent of these offerings – both in terms of financial investment and warranty security –are the solar panels themselves.
Solar panels come in a variety of power ratings. For residential applications, the most popular panels today usually fall somewhere between 270 watts and 315 watts, with price points that usually increase with the wattage (in the standard size footprint). Less obvious, however, is the type of solar panel you may be asked to choose between.
In general, your solar quote will include a panel whose cells are made from crystalline silicon. Silicon is us
ed in solar panels not necessarily because it’s the most optimum semi-conductor available – but because of the extensive research on the processing and physics of silicon grown out of the integrated circuit industry. The processes used to access and arrange the silicon determine whether a panel is deemed to be
As the name suggests, monocrystalline panels utilize a single, continuous crystal structure in the processing of the silicon ingots from which the solar cells are made. It used to be that this high-grade silicon resulted in substantially higher efficiency rates than other solar panels. However, improvements to manufacturing in polysilicon processes have closed this gap significantly. Still, homes and businesses looking for the highest possible efficiency rating on a solar panel would likely choose a Mono panel.
The silicon ingots used for manufacturing the solar cells for Poly panels are manufactured by melting many fragments of silicon together to form the ingot. Because this results in many crystals in each cell, there is usually less freedom for the electrons to move. As a result, polycrystalline solar panels typically have lower efficiency ratings than monocrystalline panels.
Should I choose a Mono or Poly solar panel?
As with any choice it comes down to buyer preference:
Aesthetics: In general, Mono panels have more options if you are concerned with how your solar panels will look. If you want something low-profile; maybe a uniform, all-black aesthetic devoid of white lines, silver racking and diamonds – most manufacturers offer this aesthetic in a Mono panel. However, there are now a few poly panels available in all-black. For example, REC has a 280-watt poly panel on the market that is now available in all-black.
Cost: Mono panels tend to cost more than poly panels. A small roof looking to get the highest possible solar fraction by going with a high wattage solar panel will most likely end up with a Mono panel as these include the highest wattage options (300w plus). However, if a homeowner has the roof space and is looking for the highest possible value, it may be most cost-effective expand the array by one or two more panels and go with a Poly. Many commercial applications utilize poly panels due to the focus on cost over aesthetics, particularly if the panels are not visible from the ground, due to a flat roof installation.
Performance: Due to the amount of information out there disparaging efficacy of poly panels compared to monos, this is a subject worth broaching. It is true that under factory test conditions, poly solar panels tend to have slightly lower heat tolerance than monocrystalline solar panels. As a result, under high temperatures, poly panels would perform slightly worse than their mono counterparts. Heat can affect the production performance of solar panels and shorten their lifespans. However, this effect is minor, and most homeowners do not need to take it into account. This is evidenced by the standard 25 year manufacturer’s warranty is the same for both mono and poly panels.