Monocrystalline vs Polycrystalline Solar Panels: Which is Best for You?

Buying new solar panels can be a headache.

There’s too much to consider, isn’t there?

What size? What power? What type?

And then you start stumbling across the technical specifications like monocrystalline and polycrystalline!

If you’re like me, all you really want is to be getting free electricity from the sun as efficiently as possible.

Well, the difference between monocrystalline and polycrystalline solar panels is a key consideration before making your final choice.

In fact, the correct decision here helps you save a lot of money and produce energy more efficiently.

Let’s take an easy-to-understand look at monocrystalline vs polycrystalline. By the time you’ve read this article, you’ll be in no doubt of which is best for your setup.


What are Monocrystalline and Polycrystalline Solar Panels?

When it comes to solar panels for your home or off-grid power requirements, there are two types to choose from – monocrystalline and polycrystalline.

The difference is very subtle but has a big effect on the efficiency and price.

Monocrystalline is more efficient while polycrystalline is cheaper.

Both types of panels use solar cells made up of silicon crystals.

And the difference all comes down to the way these crystals are formed to create the solar cells.


What is a Monocrystalline Solar Panel?

Monocrystalline solar panels are more efficient at absorbing sunlight and converting it into electricity.

Each of their solar cells is from a single silicon crystal which makes each cell purer. This pure clean piece of silicon results in high efficiency, plus better performance in high heat and low light conditions.

Due to the care needed in the manufacturing process, monocrystalline panels are more expensive when compared to the same power polycrystalline versions. 

The other downside of monocrystalline is that the manufacturing process results in increased waste as the silicon is shaved down to meet the required cell shape.

You can easily spot a mono panel by the deep black color of the cells.

Mono cells are black with corners cut off

What is a Polycrystalline Solar Panel?

Known as ‘poly panels’ for short, they are cheaper but less efficient at absorbing sunlight and converting it into electricity.

The solar cells are easier to create as they are made using lots of pieces of silicon. Multiple pieces of crystal are molded together in each cell. When you look closely at a poly panel you will see lots of small shards across the face of the cells. It’s these imperfections that reduce efficiency. In addition, they tend to struggle more with high temperatures which reduce the efficiency during the hottest days.

Another distinctive feature is the blue color of the panel, which some people prefer for aesthetic reasons. 

Poly cells are blue and completely square in shape

An easy way to remember the difference is by the mono and poly. 

  • Mono means one in Latin so it relates to one crystal in each cell.
  • Poly means muti in Latin so it relates to multiple crystals in each cell.

Monocrystalline and Polycrystalline Comparison

For quick reference here is a handy table summing up monocrystalline vs polycrystalline solar panels:

MonocrystallinePolycrystalline
CostMore expensiveCheaper
Conversion EfficiencyOver 20%Under 20%
Cell StructureSingle silicon crystalMultiple pieces of silicon
Durability30 – 40 years25 – 35 years
AppearanceDark blackBlue hue
Temperature performance 
(temperature coefficient)
Best performance in high heat 
(lower temperature coefficient)
Lower efficiency in high heat
(higher temperature coefficient)
Low light performanceGoodPoor
Best UsesSpace is limited and efficiency is importantPlenty of space and cost can be reduced

What’s Best for You? Monocrystalline or Polycrystalline Solar Panels?

With an overall understanding of the difference between mono and poly solar panels, we can now take a deeper look to help you pick the best solution for your system.

Cost

The manufacturing process is what creates the cost difference between the two types of solar panels. It is much easy to create poly solar cells as the silicon is simply poured into a mold and left to set. Contrastingly, it takes much more care and precision to create mono cells. Creating a single crystal to form the shell is a complex process that costs more to execute.

When working out the costs for your solar panel systems there are a few things to keep in mind:

  • Monocrystalline is more expensive initially but increased efficiency can save you money in the long run.
  • The rest of the equipment such as cables and charge controllers are the same for both mono and poly panels.
  • Poly panels are not as durable and might need replacing sooner.

Efficiency

At the heart of this debate is efficiency. We all want to best performing products in our price range. 

There is no about that mono panels have higher efficiency when converting sunlight to electricity. In fact, can expect a conversion efficiency of over 22% compared to less than 20% for poly panels.

This means that when you have limited space, you are better off with monocrystalline. If you have a mono panel and a poly panel of the exact same size, the mono panel will generate more electricity. For example, when they are the same size, a mono panel can produce 230 watts while a poly panel produces 200 watts.

In practice, this means when covering a small roof, you can get a power benefit from the more efficient panels. 

On the other hand, if you have a large area the space you have for solar panels can easily meet your power requirements with polycrystalline. And you might find that costs are adding up. In this scenario, efficiency might be less of a concern when compared with efficiency.

Temperature Coefficient

Another performance element is the temperature coefficient.

This is how well the solar panels perform at different heat.

The lower the coefficient number the better efficiency it has at higher temperatures.

Monocrystalline solar panels have a lower temperature coefficient meaning they don’t lose so much performance when it’s hot.

Polycrystalline solar panels have a larger temperature coefficient rating which means the efficiency reduces more at higher heat.

Color

If you’re thinking about the aesthetics of your solar panels then there is a contrast between the two types.

Monocrystalline is a deep black color due to its cell structure which absorbs a higher amount of sunlight. 

large 300 watt monocrystalline solar panels
Large 300 watt monocrystalline solar panel

Some people actually prefer the blue hue to polycrystalline as the shards of silicon react in this distinctive way to sunlight.

Durability

Finally, let’s consider the lifecycle of the two forms of solar panels.

Don’t be fooled, both have an extremely long lifespan as the cells are always wrapped in anti-corrosive aluminum and tempered glass. They are designed to be used outside for decades.

In fact, you should expect any traditional solar panel to last over 25 years. That being said, many people claim to see a quicker degradation from polycrystalline compared to the single-cell structure of monocrystalline. 

Solar panels can last decades even when left outside

Other Types of Solar Panels

On the odd occasion, you might have come across another type of solar panel called thin film. To be honest, these are not suitable for the average person and are generally reserved for commercial applications. 

This is because the manufacturing process and performance are vastly different. There are no crystalline cells. Instead, a thin layer of conductive material is laid on a glass or plastic plate. 

This is much cheaper to manufacture but far less efficient at generating electricity which is why they are not suitable for residential use. Thin-film solar panels are commonly used for large-scale or unique projects. 


FAQ Polycrystalline vs Monocrystalline Solar Panels

Now let’s go through the final questions you still might have on the subject.

Is polycrystalline or monocrystalline cheaper?

Polycrystalline is cheaper than monocrystalline. This is because the poly panel cell structure is made up of multiple shards of silicon which is easier to produce. Monocrystalline cells have a single silicon crystal which requires more care and expertise to create.

What is the most efficient solar panel type?

Monocrystalline solar panels are the most efficient. This is because of the structure of each cell which is made using a single piece of silicon crystal. You can expect monocrystalline to have a conversion efficiency of over 21% while poly panels are less than 20% efficient. 

Which solar panel is better monocrystalline or polycrystalline?

Monocrystalline solar panels have better performance while polycrystalline solar panels are cheaper. If you are limited in space then monocrystalline will be a better investment in the long run.

Are Monocrystalline solar panels worth it?

Yes, it is worth spending extra money on monocrystalline solar panels as they will be more efficient. This efficiency can save you money on energy bills over a long period of time.

What are the advantages of polycrystalline solar panels?

The main benefit to poly panels is the price. They are cheaper than mono panels which are good for people on a tight budget. Polycrystalline is still highly durable and will work for decades. Adding to this, if you have a large area available to cover then efficiency is less important when compared to the total cost.

How long do monocrystalline solar panels last?

Monocrystalline solar panels should last for 25 years or more. Residential solar panels should come with a power output warranty of 25 years. Many people say their solar panels can last 30 or 40 years if maintained correctly.

Can you mix monocrystalline and polycrystalline solar panels?

It is best not to mix monocrystalline and polycrystalline solar panels. This is because their efficiency and power output can vary leading to inconsistencies in your systems. If you do want to mix solar panels then you should consult a professional for the best setup.

How can you tell the difference between monocrystalline and polycrystalline?

You can easily tell the difference between monocrystalline and polycrystalline by the color of the solar cells. A mono panel is a deep black while a poly panel is blue. You can also see the different cell structures up close. In polycrystalline you can clearly see the shards of silicone in each cell. Comparatively, monocrystalline cells will be smooth and dark.


Final Words on Monocrystalline vs Polycrystalline

By now you should be an expert in comparing monocrystalline and polycrystalline solar panels.

Realistically, it all boils down to efficiency and price.

Monocrystalline is more efficient.

Polycrystalline is cheaper.

It is also useful to know how to spot the difference between the two types. That way you can be confident you are getting what you pay for. A mono panel will be a deep black color while poly panels have a distinct blue hue.

Now the final decision is up to you…

Personally, if you can afford it,  I’d always go for monocrystalline as the performance is a better investment over the years.