Mono PV panels are more efficient but are more expensive – the price is coming down so is now the time to consider them for your new system?

The primary difference between mono and poly solar panels is the structure by which silicon is shaped and moulded into the panel. In mono crystalline solar panels, silicon is formed into bars, then cut into wafers, whereas poly crystalline solar panels are melted together to form wafers. The process to create mono solar panels was invented in 1918. As a result, the earliest solar panels were of the mono crystalline design.

However, during an oil crisis-induced burst of solar energy research in the 1970s, an Exxon researcher discovered that poly panels could be manufactured more cheaply.

As we are seeing in the greater efficiency and steady decline in cost for mono panels as of late, the cheap manufacturing of poly had its own hidden costs.

As 2018 rolls along, some analysts are predicting that this may be the year in which mono crystalline solar panels make up the majority of solar panels manufactured worldwide. The rapidly declining cost of solar energy, even in the face of resistance by the United States government, demonstrates the possibility that a rapid transition to renewable energy may not be as far-fetched as current reality may make it seem.

Poly Panel Advantages

• The process used to make polycrystalline silicon is simpler and cost less. The amount of waste silicon is less compared to monocrystalline.
• Polycrystalline solar panels tend to have slightly lower heat tolerance than monocrystalline solar panels. This technically means that they perform slightly worse than monocrystalline solar panels in high temperatures. Heat can affect the performance of solar panels and shorten their lifespans. However, this effect is minor, and most homeowners do not need to take it into account.

Poly Panel Disadvantages

• The efficiency of polycrystalline-based solar panels is typically 13-16%. Because of lower silicon purity, polycrystalline solar panels are not quite as efficient as monocrystalline solar panels.
• Lower space-efficiency. You generally need to cover a larger surface to output the same electrical power as you would with a solar panel made of monocrystalline silicon. However, this does not mean every monocrystalline solar panel perform better than those based on polycrystalline silicon.
• Monocrystalline and thin-film solar panels tend to be more aesthetically pleasing since they have a more uniform look compared to the speckled blue colour of polycrystalline silicon.

Mono Panel Advantages

• Monocrystalline solar panels have the highest efficiency rates since they are made out of the highest-grade silicon. The efficiency rates of monocrystalline solar panels are typically 15-20%.
• Monocrystalline silicon solar panels are space-efficient. Since these solar panels yield the highest power outputs, they also require the least amount of space compared to any other types. Monocrystalline solar panels produce up to four times the amount of electricity as thin-film solar panels.

• Monocrystalline solar panels live the longest. Most solar panel manufacturers put a 25-year warranty on their monocrystalline solar panels.
• Tend to perform better than similarly rated polycrystalline solar panels at low-light conditions.
• Monocrystalline solar panels tend to be more efficient in warm weather. Performance suffers as temperature goes up, but less so than polycrystalline solar panels. For most homeowners temperature is not a concern.

Mono Panel Disadvantages

• Monocrystalline solar panels are the most expensive. From a financial standpoint, a solar panel that is made of polycrystalline silicon (and in some cases thin-film) can be a better choice for some homeowners.
• If the solar panel is partially covered with shade, dirt or snow, the entire circuit can break down. Consider getting micro-inverters instead of central string inverters if you think coverage will be a problem. Micro-inverters will make sure that not the entire solar array is affected by shading issues with only one of the solar panels.

Although quality technology is important in selection of solar panels, it is also critical to keep in mind that both monocrystalline and polycrystalline silicon solar cells are proven technologies, and one should not automatically be considered better than the other. Manufacturing equipment for silicon wafers is now more readily available now than it ever has been in the past, however, so panels are relatively easy for companies to manufacture. A key differentiating factor between the quality manufacturers and the bottom-line ones is whether the company in question invests in research and development (R&D). R&D investment by a manufacturer is usually indicative of the company’s commitment to creating innovative and quality products, but it also shows that the company is planning to be in the game for the long-term, and is not a fly-by-night operator.

For most households, balancing affordability with reliability is key. Solar power systems are ordinarily expected to continue operating for 30+ years; solar panel warranties generally cover products for up to 25 years. Warranties are will only continue to be serviceable if the manufacturer behind them remains a solvent company. Although it is impossible to know for sure what will happen a quarter century in the future, when selecting a panel, it is still advisable to try to imagine whether the product’s manufacturer is likely to be around at that point in time, just in case something goes wrong in the meantime. Otherwise, if the panels need repairing, the cost could end up being greater than an initial investment in more reputable product would have been.

Energy Stuff can supply both Poly and Mono panels from Jinko one of the world’s largest Tier 1 PV manufacturers.