What is a Polycrystalline Solar Panel?
Polycrystalline panels are considered old technology now, but they are still a very popular choice in developing nations, on solar farms and for DIY solar projects.
When you look up at a solar array on someone’s roof or drive past a huge solar park, if the panels have a blue hue about them … they are polycrystalline solar panels.
You can still see them ‘out in the wild’ on older, domestic solar systems too.
But what does polycrystalline mean? Let’s take a close look at these iconic panels.
How do Polycrystalline solar panels work?
All solar systems installed for the purpose of generating electricity incorporate PV panels.
The PV stands for ‘photovoltaic’ which means they convert light particles from the sun, or photons as they are known, into DC power.
This is what differentiates them from ‘thermal’ solar panels that use heat energy from the sun to warm water, food and other materials.
The cells within photovoltaic panels are made from the Earth’s second most abundant element, Silicon.
Silicon is one of the few elements that react to sunlight to generate electricity.
The photons hit the electrons inside the silicon and cause them to ‘jiggle n jump’, the resulting energy flows across the cell, out through the cables and into your home.
That’s very simplistic but does kinda explain what’s going on.
Polycrystalline cells are cheap and easy to manufacture because the crystals inside the silicon are mashed together, rather than separated like they are in a monocrystalline panel.
While this makes polycrystalline panels a little less efficient, it means they are also much more affordable.
Learn more about how solar panels work.
Where would you use a Polycrystalline Solar Panel?
As polycrystalline panels aren’t very popular in the UK right now this wouldn’t be something we’d recommend you’d use.
For information’s sake though, we’ll take a peek at what’s still available.
One reason for using a poly over a mono is they have a smaller carbon footprint.
The manufacture of polycrystalline silicon is much easier and less time consuming than creating single crystal silicon for mono panels.
The less energy you use creating the materials, the more eco-friendly the end product is.
What’s more, mashing all the crystals together in one ‘lump’ creates much less waste – so, once again, much greener!
Polycrystalline solar panels function well between 85 °C and -40 °C.
They do have a pretty low tolerance to heat though, so as things heat up on the roof, the panels get less and less efficient.
How much do Polycrystalline Solar Panels cost?
Trying to get a quote for polycrystalline panels in the UK is not an easy task, but you will find the odd one or two online.
There is also an abundance of second-hand panels becoming available as people update their systems with more efficient units.
When pricing up solar panels, no matter what way they are made, you will be looking to buy as many as your needs dictate.
The best way to look at pricing solar panels is to decide how many square metres you need to get the yield you are after – this means you can price by the metre rather than kWh.
Using this metric, the prices range from about £90 – £120 per square metre.
Learn more about solar panel costs.
Advantages of Polycrystalline solar panels
Low Cost
As we stated before, the manufacturing process for polycrystalline panels is much simpler than mono panel production – and simpler means cheaper.
Monocrystalline panels are much more efficient but much harder to produce, so they usually come with much higher price tags – between with the square metre metric, they come in at about £120 – £350.
Slightly Greener
As we have mentioned, the price of a polycrystalline cell is much cheaper due to not separating the silicon into single crystals.
The nice side effect of that is, the process wastes less silicon because nothing is thrown away.
Less waste means less mining silicon, less purifying silicon and less power needed overall.
Longevity
Luckily, all solar panels last for absolutely ages, regardless of how they are made.
There are no moving parts in a solar panel, and all the action happens at an atomic level, so there’s not much that can go wrong.
However, silicon degrades year on year and there is nothing you can do about that.
This degradation means the panels gets 0.4% less efficient every year – by the end of 25 years they are down to 80% of their original efficiency.
This is the industry standard for a panel being at the end of its life, but they will continue to generate electricity for decades after.
This is why many DIY enthusiasts buy second-hand polycrystalline panels.
Disadvantages of Polycrystalline solar panels
Less Yield
Unfortunately, this is the result of not splitting the silicon into single crystals.
The crystals in a polycrystalline panel are all ‘mushed’ together so, when the electricity is generated, it experiences more resistance as it tries to travel across the panels and into your home.
This drops the efficiency and, therefore, the amount of power each panel can produce.
Learn more about the pros and cons of solar panels.
Polycrystalline vs monocrystalline solar panels
This blog may have put a bit of a downer on polycrystalline panels, but they are still very useful bits of kit.
If you have plenty of room to lay panels out, you may save money by installing polycrystalline panels over a wide area.
This also makes them a good choice for a solar farm.
Specs | Polycrystalline | Monocrystalline |
Efficiency | 13% – 19% | 19% – 24% |
Cost | £90 – £120 per m2 | £120 – £350 per m2 |
Lifespan | 25 years plus | 30 years plus |
Manufacturing | Cheaper and less wasteful | Expensive and wasteful |
Appearance | Blue/white and black | Black on black |
Learn more about solar panel efficiency.