The Different Types of Solar Panels Explained

The case that we need to reduce our dependence on fossil fuels is now inarguable. Not only are they bad for the environment but, as we’ve seen, they can leave us hostages to the fortunes of the global wholesale energy market to our considerable cost. Solar energy is not only a reliable and lasting energy source but also a very cost-effective and efficient one. 

But you don’t have to do too much research before it can start to look a little bewildering. There’s a plethora of different types of solar panels out there, and if you want to maximise your business energy efficiency you must choose the right one to match your specific needs. This guide to the different types of panels should help to demystify it, a little. 

Monocrystalline panels

What are they? Monocrystalline solar panels are the oldest form of solar panel. They’re made of single-crystal silicon, which is melted into bars, cut into wafers, and treated with an anti-reflective coating which improves its efficiency and gives it a darker appearance.

What are their benefits? The dark colouring gives them a more aesthetically pleasing appearance, and they’re usually the most energy-efficient solution for domestic users. 

What are their drawbacks? They’re more expensive than other options. 

How much does an average 350w panel cost? Around £700. 

What’s their energy efficiency rating? Around 15%-24%

What’s their average lifespan? Around 25-40 years.

Polycrystalline panels

What are they? Polycrystalline solar panels are made by melting multiple silicon crystals and pouring them into a square mould, which creates this panel's blue mosaic look.

What are their benefits? They're slightly more environmentally friendly than monocrystalline panels, because less silicon is wasted during the process, and they're often the cheaper option. 

What are their drawbacks? Saving money on the panels themselves comes at a cost. Polycrystalline panels cost more per watt produced because they’re a third less efficient than monocrystalline panels. Some may find them a less aesthetically pleasing option on account of their colour. 

How much does an average 350w panel cost? Around £560. 

What’s their energy efficiency rating? Around 13%-16%.

What’s their average lifespan? Around 25-30 years. 

Thin Film panels

What are they? Thin film solar panels are created by placing several thin layers of photovoltaic material – amorphous silicon, cadmium telluride, copper indium gallium selenide, or organic PV cells – on top of each other. Photovoltaic panels are installed for the conversion of thermal energy into electricity, while solar panels convert solar radiation into heat.

What are their benefits? Their thinness makes them more flexible than other types of solar panel. They can even wrap around surfaces, which makes them a good solution where roof space is extremely limited. They also tend to be cheaper than both monocrystalline and polycrystalline panels. 

What are their drawbacks? They produce a lower wattage and have a significantly lower energy efficiency rating than monocrystalline and polycrystalline panels.

How much does an average 350w panel cost? Around £415. 

What’s their energy efficiency rating? Around 7%-13%.

What’s their average lifespan? Around 10-20 years.

Transparent panels

What are they? Transparent solar panels can be placed on top of glass so you can generate solar energy while still letting sunlight through. They're typically used on commercial buildings, where savings can be multiplied across hundreds or thousands of windows.

What are their benefits? They can be used on multiple surfaces, and their clearness means that they’re no more aesthetically displeasing than windows. Letting sunlight through is also a big benefit. 

What are their drawbacks? They’re expensive, have a low-efficiency rating, and you need a lot of them to start generating substantial savings. 

How much does an average 350w panel cost? Around £1900. 

What’s their energy efficiency rating? Around 1%-10%.

What’s their average lifespan? Around 25-30 years. 

CPV Panels

What are they? CPV stands for "Concentrator Photovoltaics", a process by which sunlight is concentrated with curved mirrors or lenses, and directed onto small, super-efficient solar cells. They typically use solar trackers to ensure they get the most sunlight at all parts of the day, and cooling equipment to stop the network from overheating.

What are their benefits? They are extremely efficient and can generate energy even in low light. 

What are their drawbacks? They’re not available at all for domestic users, and the prohibitively high cost means that they’re primarily used by energy companies only. 

How much does an average 350w panel cost? N/A. Unless you already run an energy supplier, you can’t afford them. 

What’s their energy efficiency rating? Around 35%-50%. 

What’s their average lifespan? 25-35 years.  

PERC panels

What are they? PERC stands for Passivated Emitter and Rear Contact, a technological system that can be added to any domestic solar panel in the manufacturing process to give it an efficiency boost by making the rear side of the solar panel (which faces your roof) reflective, bouncing any unabsorbed light back through the cell, so the front side has another opportunity to absorb it.

What are their benefits?  They’re more efficient than traditional panels, less likely to lose efficiency from overheating, and tend to be cheaper than ‘top-tier’ panels.

What are their drawbacks? They’re less efficient than top-tier panels and are starting to fall from favour with manufacturers. 

How much does an average 350w panel cost? Around £820. 

What’s their energy efficiency rating? Around 17%-20%. 

What’s their average lifespan? Around 25-35 years. 

Perovskite panels

What are they? Perovskite solar panels are made using perovskite, a synthetic material inspired by the crystal structure of a mineral with the same name. This material is layered on top of standard silicon. Silicon can already absorb the red end of the solar spectrum, but perovskite can absorb the blue part.

What are their benefits? They have a higher efficiency than any solar panel on the market, take up the same space as monocrystalline panels, and will cut your energy bills by much more than other types.

What are their drawbacks? The biggest drawback is that you can’t buy them yet, and the second biggest drawback is that when they are released into the market they’ll likely be very expensive. 

How much does an average 350w panel cost? N/A.

What’s their energy efficiency rating? Around 29%-34%.

What’s their average lifespan? Around 25-35 years. 

Solar Tiles

What are they? Solar tiles are for those amongst us who value aesthetics above everything else. They’re designed to look like normal roof tile, and this means that they blend in perfectly with your roof, though you'll need to get your entire roof replaced during the installation.

What are their benefits? They blend in with your roof tiles, making them practically invisible. In addition to this, they’re more durable than normal solar panels and avoid regulations on listed buildings and conservation areas. 

What are their drawbacks? They have a worse efficiency rating than modern solar panels while also being expensive, meaning that you probably won’t break even through cost savings. As such they’re only really justifiable for use on listed buildings or those in conservation areas. 

How much does an average 350w panel cost? Around £825.

What’s their energy efficiency rating? Around 10%-20%. 

What’s their average lifespan? Around 25-30 years. 

Solar Thermal Panels

What are they? Solar Thermal panels are designed to heat up your domestic hot water, rather than to provide electricity. They’re composed of either flat plate panels or evacuated tube collectors that collect warmth from the sun, which heats a mixture of glycol and water. This mixture then flows to a heat exchanger inside your hot water tank and transfers its warmth to your water supply.

What are their benefits? They’re easy to install, relatively cheap, and will typically cut your heating bill in half.

What are their drawbacks? They only provide hot water rather than electricity, and they can’t provide 100% of your hot water, either. 

What's the average cost for a 3-bedroom household? Around £4,000, including installation. 

What’s their energy efficiency rating? Up to 70%. 

What’s their average lifespan? Around 15-20 years. 

Best Type of Solar Panel for Commercial Needs

On the whole, you’ll want to install the best quality solar panels that you can afford. Ones that are energy-efficient, durable and cost-effective. Monocrystalline solar panels are often the preferred choice for businesses, offering high conversion rates and small footprints. 

Ultimately, however, your choice of solar panel will depend on your physical space and power needs. When deciding on the best solar panel for commercial use, it’s crucial to consider factors such as the specific application scenario, energy demand, budget, and long-term investment costs. 

Conducting detailed research, comparing specifications, efficiency ratings, and warranties, and consulting with solar professionals can help you make an informed decision that aligns with your requirements and maximises your return on investment.

Factors Influencing Solar Panel Efficiency

If you’ve decided to take the plunge and get solar panels installed, you need to understand how to maximise their efficiency. Having your solar panels work as efficiently as possible is the best way to maximise your return on investment. Some of these factors include:  

Temperature coefficient

The temperature of a solar panel can affect its ability to generate energy. This loss of output is reflected through the temperature coefficient, which is a measure of the panel’s decrease in power output for every 1°C rise over 25°C (77°F). 

Monocrystalline and polycrystalline panels have a temperature coefficient between -0.3%/°C to -0.5%/°C, while thin-film panels are closer to -0.2%/°C. This means that thin-film panels can be a good option for hotter environments or places that experience more sunlight throughout the year.

Angle of sunlight

We know how much energy we can potentially get from the sun, so we need to ensure the solar panels are installed in the very best position to mop up every kWh we possibly can. We learn from a very early age that the sun rises in the east and sets in the west so, in the Northern Hemisphere, that means pointing the panels due south. If the panels are pointing south the sun will shine on them from dawn until dusk.

If your home’s roof is at a perfect 35-degree pitch and is facing directly due south, it will receive 95% of the light energy each year. Truth is, even if your house roof isn’t pointing due south, but the panels can be at 35 degrees, panels facing southeast or southwest will still be soaking up 80% of the power they need. Even a northeast/west-facing roof, with panels at 35 degrees will receive over 60% of the energy you would get on a south-facing roof, and you can make up the shortfall with extra panels.

Shading issues

Shading, if not considered, can be very bad for solar panel systems. As much as 40 per cent of their potential solar generation could be lost due to shade. This is because, as a shadow is cast over a panel, the amount of sunlight reaching the surface is reduced.

Solar panels are normally connected in a series of parallel ‘strings’. This means if one panel is covered by shade from a tree or chimney, then all the connected panels within the string will also lose power. This is because the panels are wired together in such a way that the output is reduced to that of the weakest panel within the system. Shading just one cell in a module to half causes the output power of the whole module to fall to half. No matter how many cells there are in the string, completely shading one cell will cause the output power of the module to fall to zero. There are solutions to this, including installing more panels, but it should be taken into consideration when you’re choosing which panels to install and where to install them. 

Maintenance requirements

Modern solar panels are low-maintenance, but that doesn’t mean that they should be ignored once they’re installed. Cleaning your Solar Panels at least once a year will remove any dust, pollution, leaves or tree sap that can cover your solar panels. It is important to manage this and to remember that dirty panels have the same impact as shading. Pigeon or Bird-proofing your solar panels will prevent pigeons from gaining access to underneath your system. As the pigeons will no longer be able to access a safe home they will have to look elsewhere.

Can You Mix Different Types of Solar Panels?

Connecting different solar panels in a solar system is possible, but it is not recommended because either the voltage or the current might be reduced. This leads to lower output power, and therefore to less solar-generated electricity.  

Solar panels come in a variety of different wattages, and wattage mixing reduces efficiency and power. A variety of wattage panels has different voltage and amp outputs. The system always favours the lowest voltage or amp, which puts the larger panel on the back burner. This, as a result, reduces the overall efficiency and power output of your solar panel array.

Choosing the Right Solar Panel for Your Businesses Needs

Cost, energy efficiency, size (both in terms of physical size and wattage), and durability are among the factors that you’ll need to take into account if you’re considering which solar panels will best fit your business needs. Consulting with solar panel experts is strongly recommended before you go ahead with anything. 

Next Generation Solar Panels

The solar panel market is rapidly evolving, and there is considerable optimism that next-generation solar materials will be both cheaper and more sustainable to produce than traditional silicon solar cells, although hurdles remain in making the devices durable enough to withstand real-world conditions.  

Quantum Dot Solar Panels

This new solar innovation uses ‘quantum dots’, which are tiny spheres of semiconductor material – each only about 2–10 billionths of a metre in diameter. Quantum dot solar panels could seriously increase solar efficiency. Photons, the particles which make up light, can be converted into energy using these dots, dramatically increasing a panel’s potential efficiency.

Zombie Solar Panels

Zombie solar panels are a new type of solar cell that can adapt to the amount of available light. This innovation will even be able to work indoors, though it's unlikely that they will generate much energy. The cells are a type of thin film material, usually composed of a dye that absorbs light. This encourages electrons to create a current, which is then carried to the cell’s electrodes by a liquid electrolyte solution.

The market is still evolving, but there are already substantial benefits to getting solar panels installed. Upfront costs can be high, but your return on investment should outweigh that, and lengthy guarantees from manufacturers help to ensure that they can be a long-term way of significantly reducing your energy bills while doing the right thing for the environment. Making that switch now will keep you ahead of the curve when it comes to changes which will be coming regarding the use of fossil fuels in the future. You can even use them to show off your green credentials to potential customers or other business partners. Get an appointment with a solar specialist, and you could be taking your next steps towards a greener, cleaner future.