✔ Cheap solar panels are often only less efficient than premium ones
✔ They often degrade faster than premium solar panels
✔ Solar panels only make up 20% of the total cost of a residential solar PV system
Solar panels are a great investment, but as they are quite expensive some homeowners choose to go with the cheapest models, in order to reduce upfront costs.
This is very understandable, but unfortunately, cheap solar panels can end up being more expensive in the long term.
Price is often (though not always) a reflection of quality, and cheap solar panels can last less long than their pricier counterparts, or be more prone to issue.
This is something important to consider before buying the cheapest panels on the market.
We’ll explain why the best solar panels are worth the extra cost in this article, and tell you which factors to consider when choosing a solar panel, so you can make an educated decision.
If you’re ready to start comparing solar panel quotes, just fill in this short form. We’ll pass your details onto professional solar panel installers, who will get back to you with their best prices.
What’s wrong with cheap solar panels?
When it comes to solar panels, cheaper is not necessarily better. That’s because cheaper panels often have a number of issues that mean they don’t work as well or last as long as more expensive panels. They can also require considerably more maintenance.
The average price of a 3.5 kilowatt peak (kWp) solar PV system – suitable for the average three-bedroom house – should be around £7,026. This figure includes the cost of the inverter and installation. So, if you’re paying significantly less than £7,026 for a 3.5 kWp system, that may mean the manufacturer is cutting corners somewhere.
Cheap solar panels typically don’t generate as much electricity as more expensive, better quality ones, so you might break even on them later.
They also lose efficiency quicker over time than high quality solar panels, and they’re more likely to give you multiple maintenance issues during the time they spend on your roof.
How do you judge the quality of solar panels?
Price isn’t everything, and it’s important to look at common quality indicators when assessing a solar panel.
Key quality indicators for solar panels include efficiency, temperature coefficient, linear output warranty (also referred to as performance warranty) and manufacturing process.
Solar panel efficiency
Solar panel ‘efficiency’ refers to the percentage of sunlight that a panel can convert into electricity. The more efficient a solar panel, the better it will be at powering your home.
The best solar panels are at least 20% efficient, and can be up to 23% efficient, so aim for solar panels that are close to these levels of efficiency. Cheap solar panels, on the other hand, typically have an efficiency rating of 16% at best.
Linear output warranty and durability
‘Linear output warranty’ refers to a solar panel’s minimum lifespan. The majority of solar panels come with a 25-year linear output warranty, which guarantees that the solar panel will be operating at a particular percentage of its original output after 25 years. The higher the percentage, the better the quality of the solar panel.
For context, a good quality solar panel should be guaranteed to operate at at least 85% of its original efficiency after 25 years. Top tier solar panels retain over 90% efficiency in that same time frame, whereas lower-end solar panels only retain 80%, at best, of their efficiency after 25 years.
Solar panels often come with a 25-year warranty. If the manufacturer does not offer a long warranty period, this could indicate that the manufacturer does not have any faith in the durability of their product.
Temperature coefficient
Temperature coefficient refers to the impact that heat has on a solar panel’s operational efficiency after installation.
It’s measured as a percentage, that indicates how much power output is lost when a solar panel’s temperature goes above 25°C.
The best solar panels have a temperature coefficient that’s -0.32% per degree above 25°C.
Since solar panel overheating accelerates their ageing, the lower the percentage per degree Celsius, the better.
Manufacturing process
Many of the top manufacturers of high-quality solar panels have the following factors in common:
- They conduct research and development to continually improve their product and process
- They’re vertically integrated, so they can control quality at every step of the process
- They use a high-grade silicon to manufacture their solar panels
- They tend to have been around for at least 5 years, giving them time to improve their products
- The production process utilises robotics to manufacture solar panels, ensuring a uniform project
Benefits of premium solar panels
Buying cheaper solar panels has a number of drawbacks and associated costs.
So, let’s take a look at some of the key benefits from opting for the best solar panels on the market, regardless of cost.
Greater efficiency
Good quality solar panels are generally more efficient, and this largely depends on what they’re made of.
Silicon is the most commonly used material in solar panel production, and monocrystalline silicon is the best kind.
Monocrystalline solar panels are much more efficient than their polycrystalline counterparts, the second most common type of residential solar panel.
Efficiency is key when it comes to performance. For example, a solar panel with 20% efficiency can do twice as much with the sunlight it receives as a solar panel with 10% efficiency. If you’ve got limited roof space or a lot of shade going on, high-efficiency solar panels are absolutely essential.
Generally speaking, polycrystalline solar panels achieve efficiencies of 13-16.5%, while monocrystalline solar panels can break into the dizzying heights of over 22%. The most impressive module on the market at the moment is AIKO’s 72-cell N-Type ABC White Hole Series, with an efficiency of 24%.
To find out more, take a look at the most efficient solar panels.
Longer lifespan
Although most linear output warranties expire after 25 years, that doesn’t mean solar PV systems shouldn’t keep going beyond this point. Good solar panels should last as long as 30-40 years, while the lower quality alternatives don’t tend to make it so far.
Cheap solar panels are cheap for a reason; they don’t cost much to make. For example, budget manufacturers will tend to use a fairly basic type of glue, which can put their panels at risk of delamination. This is when the bond between the glass and the plastic of a solar panel starts to deteriorate, and the two layers slowly separate, making space for moisture to come in. Ultimately, this leads to corrosion and system failure.
Similarly, low-quality solar panels are also not very resistant to extremes of weather, so baking heat, heavy hail, and hard frosts are likely to cause micro-cracks on the surface of the panel. Every micro-crack is a blow to your solar PV system’s overall efficiency, and your dreams of a solar-powered home.
Sensible economics
Since the price of solar panels has fallen in the past 10 years, they have gradually shifted from being a significant chunk of the overall cost of a solar PV system, to a fairly small fraction. Although the associated costs of installation (e.g. labour, scaffolding, inverter, metre etc.) are also dropping, they aren’t coming down nearly as fast as the cost of solar panels.
In short, well over 50% of the price of a solar PV system is based on the large fixed cost of installation. In contrast, solar panels can sometimes account for no more than 20% of the overall cost, as reported by Arstechnica in 2018.
If you were to purchase 8 x 305W top-quality solar panels wholesale, it would set you back roughly £1,600. However, as we stated earlier, you wouldn’t be buying them wholesale unless you’re kickstarting a large-scale solar farm. You’d go to a professional installer such as E.On, who charges around £4,123 for an installation of 8 x 305W solar panels.
Given the current breakdown of solar costs, you can see that the type of solar panel you buy won’t make a huge difference to the overall price. You’ll be paying several thousand for installation, irrespective of what type of panel you buy. According to researchers at MIT, as well as various solar power companies, it makes economic sense to go for top-quality solar panels in order to get the most value out of the installation cost.
Next steps
So there you have it, everything you need to know about cheap solar panels.
Just remember, cheap doesn’t necessarily mean you’ll get the best deal, it’s always best to look at efficiency and performance warranties first.
Now that you know all this, the next step is to find out how much it will cost you to install solar panels at home – and we can help. Simply pop your details here, and our qualified installers will be in touch.
