Monocrystalline or Polycrystalline Silicon Solar Panels?

Which is Best: Monocrystalline or Polycrystalline?

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Monocrystalline solar panels are far superior to polycrystalline panels. 

They offer much higher efficiency, thanks to being manufactured from a single piece of crystal silicon. This allows them to be approximately 20% more efficient than the polycrystalline equivalent. 

This lower efficiency means polycrystalline panels aren’t suitable for most properties. They require around 20% more space, something most properties are severely lacking…

Lifespan is also much higher for monocrystalline units at around 25-years, compared to that of 10-15 years for polycrystalline. 

Whilst the cost of polycrystalline panels is around 15-20% less than monocrystalline, their low lifespan and poor efficiency means monocrystalline is the technology you should go for. 

Get prices for your system using high-grade monocrystalline solar panels using our configuration tool here. 

What Are Monocrystalline Silicon Solar Panels?

Monocrystalline solar panels are the most popular type of solar panel in the UK. 

To produce a monocrystalline cell, the manufacturing process starts with a single piece of crystal silicon. By using a single piece of crystal silicon, electrons have more space to move around, allowing them to create large amounts of energy and therefore, electricity. 

For this reason, a monocrystalline solar panel will offer higher efficiency than a polycrystalline equivalent. 

We use high efficiency monocrystalline silicon solar panels for our installations. 

Get prices for your setup by using our solar panel quote tool here. 

What Are Polycrystalline Silicon Solar Panels?

Polycrystalline solar panels are outdated technology in the green energy sector. Instead of using a single piece of crystal silicon, they use fragments. 

Constructing a solar panel in this manner means electrons have very little space to move around, essentially, capping the energy they can create and as a result, the electricity they produce.

So, why are manufacturers still producing them? 

Put simply, the manufacturing process for polycrystalline panels is simple, and that means their cost is lower. 

What’s The Difference?

So, what are the biggest differences between monocrystalline and polycrystalline PV panels?

1. Lifespan

The lifespan of monocrystalline solar panels is far superior when compared to polycrystalline. 

UKSOL is a well known brand in the UK, producing polycrystalline panels. Whilst they offer a 30-year performance guarantee, this only relates to degradation rate (maximum reduction in efficiency over a specific time period). 

According to their specs, this means: 

• Reduction of efficiency to a max of 90% compared to their original output in years 1-10
• Reduction of efficiency to a max of 80% compared to their original output in years 11-30

Their actual product warranty is only 12-years, which gives an indication of how long they expect their panels to last.

By comparison, leading brands producing monocrystalline solar panels generally offer a 20-25 year warranty. ‍

2. Efficiency

As we’ve mentioned above, you’d be looking at a degradation rate that ends up in approximately 80% of initial output by year 30 with a polycrystalline solar panel. And to start with, that efficiency isn’t particularly high; 16-20%.

Compare that with the likes of LONGi, who offer a day 1 efficiency rating of 23.2% (Hi-Mo X6).

Better still, you’ll have a 25-year performance warranty meaning that even after 25-years, you’ll have an efficiency rating (compared with initial output) of 88.90%. That’s a big jump from the 80% of the polycrystalline panels mentioned above…

You can see the full specs of the LONGi X6 here.

Like the sound of LONGi’s high efficiency ratings? See our LONGi review here to find out if they’re suitable for your property.

Or, get quotes on a system using high efficiency panels here. 

3. Size

Solar panels are generally installed on a property's roof (although they can be ground mounted if you have a suitable space). 

Due to monocrystalline solar panels being much more efficient, they'll need less space than polycrystalline. 

An average polycrystalline silicon panel is going to be approximately 20% less efficient than a monocrystalline equivalent. That's going to directly correlate to you needing around 20% more roof space to produce the same amount of electricity. 

For a 5kW setup (the most popular size we install), you'd need 25-30m2 using monocrystalline panels, but 30-35m2 if you plan to use polycrystalline. 

Most properties we install solar panels at are already lacking in space, so monocrystalline is the only option. 

You can get prices on a suitable solar panel system for your property using our roof scan tool here. 

4. Cost

As you can see, polycrystalline solar panels don’t really have any benefits when compared directly to monocrystalline units. The only benefit? The cost. 

Depending on the manufacturer you choose to buy from, expect monocrystalline solar panels to be around 25-50% higher in price in comparison to polycrystalline. 

However, that doesn’t correlate to a 25-50% increase in overall installation cost. 

A typical solar panel kit suitable for an average UK property is going to be around £8,000 including a small storage battery. Yet, the solar panels themselves are likely to cost around £3,000. 

By choosing polycrystalline panels (which offer lower lifespan and efficiency as well as taking up more space), you’re likely to save a maximum of £1,000…which in our opinion, simply isn’t worth it! 

We’d always suggest using monocrystalline panels. The upfront cost will be easily offset by their higher efficiency and longer lifespan!

Get prices on your solar setup using monocrystalline panels using our tool here. 

Or, if you want to research prices further, read our guide covering the cost of installing solar panels. 

We also have a generic guide covering everything you need to know about solar panel installation here.