The first thing you need to know when looking for the most efficient solar panels is that high efficiency does not always provide the highest return on investment.
When deciding which solar panels are the best for your project, you should consider a system that will offer you the best financial benefits rather than just the most efficient solar panels. If you have enough space around your house or on the roof, then cheaper panels with lower efficiency could be a better choice since they can produce the same amount of energy you need by simply installing more of them.
This doesn’t mean that premium panels are not worth the money. The high efficiency solar photovoltaic panels available on the market today are made by reputable companies that use the latest technology, have first-class engineers, and offer high level of quality assurance. These are clear advantages over the cheaper panels.
With this in mind, let’s take a closer look at the different types of solar panels, their applications, efficiency rating, advantages and disadvantages, and hopefully this way you will find the one that’s right for you.
Monocrystalline vs. Polycrystalline vs. Thin-Film | The Comparison of Solar Panel Efficiency
There are three common types of technology used in manufacturing solar panels, these are monocrystalline, polycrystalline, and thin-film. Each of them provide different benefits, and choosing the right one depending on your budget and location can save you thousands of dollars in the long-term.
Monocrystalline: Most efficient
Monocrystalline silicon solar PV is the oldest and most developed technology to deliver the highest efficiency, as measured by power output related to the panel’s size.
The monocrystalline solar panels are manufactured by using the Czochralski method, with each module created from a single crystal of pure silicon. The silicon is melted, crystallized into ingots which are then cut into thin wafers, and mounted in a grid shape. They can be recognized by their darker black color, and each individual silicon wafer has rounded corners.
Monocrystalline solar panels are normally used for large-scale solar system installations, such as commercial and residential. They can also be utilized for smaller scale applications, and the size of the panel varies according to the project.
Small monocrystalline solar panels (up to 25W) can be used to charge smartphones, digital cameras, laptops, batteries etc., while large panels (40W and bigger) can be used to power any kind of household appliances such as microwaves, fridges, outdoor lighting systems, etc., or connected to a solar array to power entire houses.
Pros and cons of monocrystalline solar panels
- Monocrystalline solar panels have the highest efficiency rate (15-22 percent) because they are made out of high purity rating silicon.
- They require the least amount of space compared to the other two types (polycrystalline and thin-film). They are especially great for urban areas with limited space, but even off-the-grid locations.
- One of the best advantages of monocrystalline panels is the focus it gets from researchers. Since they are already the most efficient panels on the market, more time and effort is dedicated to their development and improvement in efficiency.
- Monocrystalline panels can last 25+ years because of the high purity silicon which is very stable and inert.
- High temperatures can have a significant impact on the efficiency of a solar panel. Regardless of the panel type, electricity generation will decrease as temperature rises, but this doesn’t affect the monocrystalline panels that much. Once again, high purity silicon is saving the day.
- The manufacturing of this kind of panels is more complex and therefore the price is much higher compared to thin film solar PV modules or polycrystalline solar panels.
- If you live in an area that gets a lot of snow fall and dust, installing monocrystalline panels may not be the best choice. If they are covered by heavy snow, the fragile solar cells can be damaged and the whole circuit can break down.
Best monocrystalline PV brands
Here’s a list with the most efficient monocrystalline solar panels. SunPower clearly dominates the market but LG and Panasonic are catching up pretty fast.
SunPower is the world’s largest producer of crystalline solar panels. In 2017 the SunPower X22 360W Premium Plus solar panel entered the market and has the highest efficiency for commercially available worldwide.
With an incredible 22.2 percent efficiency, it’s very durable and features the latest solar PV technology.
Only 1 percent of panels receive a Premium Plus rating like this one.
Nevertheless, the price is premium as well.
LG have made some remarkable improvements to the cell wiring of their panels to enhance the solar collector area.
Their 365 watt NeON R solar panel features a state-of-the-art solar cell structure and it’s right behind SunPower’s efficiency at 21.1 percent.
The panel has a very high wattage output and performs much better than the older models thanks to its improved temperature coefficient.
Panasonic have implemented a different approach in their panel manufacturing, called hetero-junction solar cells development. They utilize two different layers of material (crystalline silicon and amorphous silicon) to make each cell.
This results in extremely low failure rates high quality solar panels and their Panasonic N 330W panel has an efficiency of 19.7 percent.
Polycrystalline: Best for price
Polycrystalline solar panels are made of a number of different pure silicon crystals melted together, and this makes them less efficient than monocrystalline panels. Recognizing these panels is easy.
The polycrystalline cells don’t have such a uniform appearance like the monocrystalline solar cells, and have a shimmering blue color as a result of the multiple crystals they were made of.
Polycrystalline solar panels come with a wide range of power ratings, from 5W to 250W or more, for small-scale and large-scale installation systems (residential and commercial).
Pros and cons of polycrystalline solar panels
- The manufacturing process is simple, making them more cost-effective than monocrystalline panels.
- After the melting process, polycrystalline cells come out into perfect square molds, significantly reducing silicon waste.
- The fast developing solar technology made the durability and longevity of polycrystalline panels very similar to their monocrystalline counterparts – 25 years. Many people that don’t want to invest too much money in a solar system, but still expect great financial benefits out of it, choose to go with polycrystalline solar PV modules.
- The efficiency of polycrystalline solar panels is usually in the range of 13-17 percent. Because these panels have lower silicon purity, they still perform better than thin-film PV modules but are less efficient than those made from a single crystal (monocrystalline).
- They require more space to get the same power output as you would with a solar panel made of monocrystalline cells.
Best polycrystalline PV brands
TrinaSolar is one of the largest manufacturers of photovoltaic solar panels in the world.
This Chinese company puts emphasis on quality and performance since 1997, and their ALLMAX-PD05.08 280W polycrystalline panel is their most versatile product.
This ALLMAX module has 17.1 percent efficiency, and is a common choice for residential and commercial customers because of its price, durability and compatibility with all major balance of system components.
YingliSolar produces solar panels not only for homes or businesses, but also large-scale power plants.
Their high-performing polycrystalline solar panels reach an efficiency of up to 16.0 percent and they have a well proven track-record of successful operations in many countries around the world.
Thin-film: Portable and light weight
Thin-film photovoltaic cells are not made of silicon and while they got the reputation as being the least efficient out of all other types, they are best suited for projects that don’t require too much power but where flexibility and portability are more important.
Thin-film PV modules are used mainly for electronic powering circuits, garden light applications, low-slope roof systems, solar fields, landfills and many other places when portable solar panels are needed. Because thin-film solar panels can weigh under 10-oz per sq. ft, they can be installed on large roofs that cannot support too much added weight.
Pros and cons of thin-film solar panels
- They are easy to manufacture (60 percent fewer process steps) and much cheaper than crystalline solar panels.
- There is not much negative impact on performance with this type of panel when exposed to high temperatures or shady spots.
- Transportation is a sector in which thin-film solar panels are dominating. They can be used to offset the refrigeration power for cold-storage trucks, installed on bus rooftops can heat and cool the bus while powering accessories such as Wi-Fi, radio, electrical outlets, etc., all without burning fuel.
- Thin-film solar panels can be used as floating solar reservoir covers to help reduce water evaporation, and in the same time provide clean and renewable energy to filter and move water. This would not be that cost-efficient with crystalline modules as they require a more complex structural reinforcement because of the weight.
- Thin-film solar cell technologies have some drawbacks, especially in the case of residential market. With an efficiency rating of between 7–13 percent, these solar panels require large space to produce a decent wattage output, making them less practical for most rooftops.
- Thin-film solar panels are less durable than crystalline panels so they degrade faster, which is why they also come with a shorter warranty.
Best thin-film PV brands
Stion is a leading producer of high-efficiency thin-film solar panels based on state-of-the-art materials, advanced technology and high-quality production processes.
Their panels provide up to 50% better performance in shaded conditions compared to mono- and polycrystalline silicon PV panels.
Solopower is a pioneer in high-performance thin-film solar science and a large-scale producer of flexible ultra-lightweight PV products.
Tips to improve the efficiency of your panels
Orientation and installation is important
Depending on the location, photovoltaic solar panels need to be installed to receive as much sunlight as possible during the day. In the U.S. the ideal positioning is when the panels face south or west because they receive the maximum amount of power from the sun in a day.
The position and angle of your home (ground or roof installation) are probably the most essential detail to consider when installing a solar array.
If you are willing to invest some extra money in a solar PV system, solar trackers are worth it. This will considerably improve the efficiency of your panels as they allow the solar array to automatically change position based on the movement of the sun.
By allowing the panels to shift their positions relative to the sun, you can see a huge gain in power generation because the panels spend so much more time in the path of direct sunlight.
One of the great aspects of tracking is that you can boost your efficiency with a new mounting system without having to actually replace existing panels.
Maintenance and cleaning activities
If too much dirt or snow accumulates on the solar panels, the efficiency will decrease and the circuits will be exposed to additional damage.
If regular maintenance and cleaning is not done, a complete failure of the solar array can happen.
Here’s a more detailed explanation of What You Need to Know About Solar Maintenance and Cleaning.
Preventing high temperature impact
During summer months, high temperature levels (especially during heat weaves) will decrease the solar system’s performance.
If you leave few inches of gap between the solar modules and the roof or ground, air can move freely and prevent the excessive heat from affecting the panels’ efficiency.
Advances in solar panel efficiency
For all its benefits, solar power generation with PV panels is not the most efficient process. On average, a solar cell will convert about 15 percent of the sunlight that hits it into usable electricity. That leaves a lot of room for improvement, and new advances have done just that.
The standard design that uses silicon crystals has limits, and there has been fierce experimentation to find new materials that work better (or can be used at a lower cost).
Right now, there are explorations going on into gallium arsenide, magnesium chloride and a mineral known as perovskite to improve the functioning of solar panels.
That’s not all. New crystal structures are being explored as well, not just new materials. Using nanoparticles to create “quantum dots” is the latest development in photovoltaics.
New innovations are leading to panels with more than 20 percent efficiency, and there have been some cells that can have more than 40 percent (but only NASA can afford them at that level).
Now, this is all about electrical efficiency. Cost efficiency is another aspect of PV development that is just as important, keeping the price tag as low as possible while still producing sufficient power. That is where magnesium chloride (a naturally occurring salt) really shines.