Panasonic Engineer's picks Solaria Axitec Canadian Solar Silfab Phono LONGi Solar Mission Solar Hanwha Q CELLS REC Trina Solar

Engineer talks. Best solar panel brands 2023

01 Apr 2021
14 min
Beginner

Tatiana IvanovaAuthor

No matter how many manufacturers there are on the market, only a dozen of them produce PV modules which deserve to be called the best solar panels 2021. Here is what made us think they are 'the ones'.

Run an expert eye over the solar panel spec sheet

Solar panels aren't the thing you can find as a freebie in a magazine to give it a try. Neither are they all-purpose, so you can't blindly follow the recommendations of other PV system owners. It seems that a solar panel specification sheet is the only unbiased source which can help you judge a PV module. Here are the main characteristics to consider and the leading brands in each category.

Solar panel efficiency: REC, 20.9%

It is about how much sunlight hitting the panel can be converted into electricity. To put it simply, a 1 m² PV module with an efficiency of 15% would produce 150 W. Normally, solar panel efficiency varies from 15% to 20%. The more efficient solar panels are, the less of them you'll need for your system.

REC 365W Alpha is a leader in this category boasting a 20.9% efficiency. It is achieved due to the increased number of wires and heterojunction (HJT) cell technology, which makes REC Alpha deliver 20% more power than conventional solar panels.

Lifelong performance: Q Cells, 93.1% of nominal power in year 10

Most solar panels are designed to last for at least 25-30 years. That's why top manufacturers provide performance warranties for up to 25 years. According to them, solar panel performance shouldn't drop below 90% of its maximum in the first 10 years and shouldn't be lower than 80% in year 25.

Hanwha Q Cells shows the lowest degradation rate on the market: max. 0.54% per year. It means the manufacturer guarantees at least 93.1% of nominal power for up to 10 years, and at least 85% of nominal power for up to 25 years. That's what we have on paper.
In reality things are going even better: Q CELLS modules show a degradation rate of 0.3%. When installed in hot climates, solar panels by Hanwha Q Cells may degrade faster, but still at a rate not higher than 0.54%.

Performance in partial shade conditions: Panasonic, less than 25% output loss

Usually there are no numbers in a panel spec sheet showing how shade-tolerant a PV module is. The thing is manufactirers can't predict for how long your solar panel will be under low-light conditions and how much of it will be shaded. However, mechanical specifications can give us an idea of how well the panel is prepared for it. For example, twin panels or those using half-cut cell technology are going to lose less energy when shaded.

Panasonic HIT 330W deserves to be the leader in this category due to the 4 bypass diodes incorporated into the module. They split the panel into 4 sectors. If a solar cell in one of the sectors is entirely shaded, a bypass diode doesn't allow it to influence cells in the other sectors. It highly reduces the risk of solar panel underperformance.

Wind resistance: Canadian Solar, 180 mph wind

Winds are an issue all year round, but especially during the hurricane season. When it comes, high winds blow from all directions, causing panels to lift up or come loose. As for PV modules themselves, wind resistance of solar panels is quite high: most of them are certified to withstand wind loads of up to 2400 Pa (about 140 mph wind).

Canadian Solar claims its panels are able to withstand wind loads of up to 4000 Pa, which equals 180 mph wind. While they couldn't potentially survive Hurricane Patricia, whose winds set a record of 215 mph on October 23, 2015, Canadian Solar modules are still much more reliable than others in extreme weather conditions. No wonder, though. Canadians have always known how to deal with harsh climates, haven't they?

Warranty: Silfab, 30-year warranty

Solar panels come with performance and equipment warranties. Performance warranty ensures that the panels produce at least 80% of their rated power output after 25 years in operation. Equipment warranty, or workmanship warranty, covers the integrity of the panel itself and protects you against defects in material and premature wear and tear.

Silfab offers the longest solar panel warranty on the market: 25-year workmanship and 30-year performance warranty.
Along with the warranty label, you may find a 'Tier 1' sign in some spec sheets. It was introduced by Bloomberg and doesn't reflect the solar panel performance or quality at all. It just shows that the manufacturer is a big brand with a good reputation in the industry. If a warranty case occurs, a Tier 1 company is highly likely to fulfil its obligations.

Cost per Watt: LONGi, $0.48/W

LONGi 380W solar panel is an example of a perfect price-quality balance. It costs as low as $0.48 per Watt, but is one of the best performing solar panels. It offers 19.3% efficiency and 0.55% degradation rate. A real bargain from a Chinese manufacturer!

Best solar panel brands

When we are planning a big purchase,like a solar panel system, we always look for the best option available. However, there isn't such a thing as the Best All Around Solar Panel. Different manufacturers focus on different qualities of their panels and, as a result, their strong points vary. That's why we've made a list of top solar market players 2021 and analysed advantages and disadvantages of their products.

Canadian Solar panels: Whatever the weather

In 2021 Canadian Solar celebrates their 20th anniversary. Just in two decades this North American company has secured a spot in the list of World's Top-10 solar manufacturers. Canadians are good at surviving in extreme weather conditions, and so are their solar panels.

Pros	Cons
Outstanding performance in low-light conditions. Canadian Solar panels lose only about 3-5% of their efficiency in bad weather when performance of other panels can drop by 20-40%.	Average performance compared to other top manufacturers: 18-19% max. efficiency.
Strong hurricane resistance. Canadian Solar panels withstand the winds of 180 mph, while a common standard across panels is 140 mph.
Low price: $0.52 per Watt.

Trina solar panels: Power of science

Chinese company Trina Solar is always a star in the news of solar technologies. Their engineers come up with all sorts of extremely efficient panels and already have set 18 solar world records in PV modules efficiency. Among their achievements is the first 500W panel followed by a 600W panel. If anything, Trina Solar engineers know well how to build a mighty panel. If maximum electricity from a square foot is a priority for you, then Trina Solar may be your go-to choice.

Pros	Cons
Trina Solar panels are listed among the most powerful on the market. The efficiency of their monocrystalline PV modules often surpasses 20%.	The company had a series of quality issues with its panels between 2011 and 2014. They’ve solved them, and hopefully history won’t repeat itself.
Budget-friendly modules: about $0.54 per Watt.

Mission Solar panels: Word of a Texan

Mission Solar is all-American project: their panels are designed, made and tested in Texas. The PV modules of Mission Solar are certified by German solar experts who certainly know a thing or two about a high-quality product.

Pros	Cons
Has the highest power tolerance ratings across all american manufacturers. Power tolerance shows how panels perform in the real world, not in lab conditions. Mission Solar modules rated -0/+3, which means that they may gain 3% of extra power in real life conditions, but they don’t lose any. In short, you are getting exactly what you pay for.	Average performance and mediocre efficiency compared to other top manufacturers: around 17-18%.
American manufacturer, speaking the same language with its customers. Easy to solve all the questions concerning the product, warranty and purchase with company offices in the same time zone.

JA solar panels: Middle of the road

JA Solar is a Chinese company founded in 2005. In September 2020 it advanced to the position of world's third biggest solar manufacturer. Their modules are considered mid-tier in terms of price and slightly more efficient than an average solar panel.

Pros	Cons
The average efficiency of PV modules is 19.53% which is around 1% higher than the average across the industry.	Non-extendable product warranty of 12 years.
Better than average energy production at high temperatures.
Performance on cloudy days is considered above average.

Phono solar panels: Fresh and smart

This Chinese company was founded in 2008 and is one of the youngest on the market. Phono Solar engineers consistently come up with new ideas and innovations for the construction and design of their solar panels. Over 20 patents have been developed, such as bifacial modules, black silicone modules and others.

Pros	Cons
Phono Solar engineers implement lots of innovations into their products. As a result, their panel efficiency can reach 22.8%.	Non-extendable product warranty of 12 years.A relatively new manufacturer of a smaller scale. Some experts suspect that clients might have problems with warranty support.
Owners note strong performance of panels in twilight, on rainy days and in the winter.	Some owners experience significant decrease in performance of panels in high temperatures.
On a cheaper side of the market: $0.52 per Watt.

Panasonic Eco Solutions: Old but gold

Panasonic has been on the solar market for over 40 years already. In fact, they were Japanese engineers who introduced amorphous panels to the world in 1980. Today, Panasonic Eco Solutions is the biggest solar manufacturer in the world. Panasonic panels are known for their outstanding efficiency which they retain even after 25 years.

Pros	Cons
Panasonic offers performance warranties for 90% of rated power in 25 years.	Panasonic panels are among the most expensive on the market: $0.95 per Watt on average.
Panasonic panels produce 10% more energy at high temperatures than panels of other manufacturers.
Panasonic engineers always look for ways to improve the shading tolerance of their panels. For example, they’ve created a panel with 4 bypass diodes. With one of its cells completely shaded, it would only lose 25% of its power output.

REC solar panel: Lowest claims rate

Founded in Norway in 1996, REC group spreaded across Europe to North America and Asia. Quality and innovations is the focus of this manufacturer. Their product is known for its reliability and the warranties are issued for 20 years.

Pros	Cons
REC Group says to have the lowest claims rate in the industry – it stands well below 100 parts per million.	REC products are more on the expensive side of the market: about $0.80 per Watt.
Some panels of REC group retain 92% of rated power by year 25.
REC 365W Alpha is an example of innovations that the company brings to the table. This panel reaches efficiency of 20.9%.

Solaria solar panels: Cool kid on the block

The Californian manufacturer has been on the solar market for around 20 years by now. The performance and warranties of Solaria panels are on point, but what makes them really stand out is their design.

Pros	Cons
Astonishing design. Reviewers often praise the appearance of polished black solar panels and admit that they do look incredibly stylish on any roof.	Solaria panels are more expensive than their counterparts: $1 per Watt.
Solaria special mounting systems of their own design reduces power losses.
Manufacturer claims that the Solaria panels produce 20% more electricity out of square foot than traditional PV modules.

Silfab solar panels: Best warranties on the market

This Canadian newcomer entered the market in 2010. Silfab swiftly rose to glory and now it is one of the top North American solar manufacturers. Their headquarters are located in Ontario, but the manufacturing plant is in Washington.

Pros	Cons
American manufacturer, speaking the same language with its customers. Easy to solve all the questions concerning the product, warranty and purchase with company offices in the same time zone.	Mid-tier in terms of efficiency (18-19%) and price ($0.68 per Watt).
Silfab offers a 30 year performance warranty on their products – longer than most in the industry. Canadians claim that even after 30 years their monocrystalline panels retain 82.5% of their rated power and their polycrystalline modules retain 79.5%.
Panels are made to withstand harsh environmental conditions, like strongs winds and heavy snowfalls.

Hanwha Q Cells solar panels: West meets East

Hanwha Q Cells is what happens when South Korean engineers meet the German solar experts. The alliance between Korean Hanwha group and Q Cells occurred in 2012 and since then the company produces modern and reliable PV modules while being relatively small. Hanwha Q Cells manages to combine the innovative spirit of Eastern engineers with German commitment to quality.

Pros	Cons
Innovative Q.AUNTUM coating makes panels absorb more sunlight and basically raises the efficiency of polycrystalline modules to the level of monocrystalline ones.	Hanwha Q Cells panels appear to be more expensive than other PV modules: about $0.65 per Watt.
Low degradation rates: 0.3% per year in moderate climates and no more than 0.54% in hot zones
High efficiency even on cloudy days and in high temperatures.

Longi solar technology: Monocrystalline specialised

The Chinese company was founded in 2000. This manufacturer focused on making monocrystalline PV modules from the beginning, leaving behind less efficient but cheaper to produce polycrystalline panels. As it is the case with many other Chinese manufacturers, the primary focus of Longi Solar is efficiency and low price.

Pros	Cons
One of the best choices among manufacturers in terms of price per watt. For example, a Longi 380W panel costs as low as $0.48 per Watt.	No polycrystalline modules.
Low degradation rate: 0.55% per year.
Offer primarily high-watt modules which allows saving money and space.

Axitec solar panel: German quality at a reasonable price

Axitec is a German company founded in 2001. The company stays committed to making reliable panels of a superb quality, but at the same time tries to make them affordable for everyone. While Axitec panels aren't setting records in efficiency or performance, you can be sure these modules will pay for themselves.

Pros	Cons
German quality and strong warranties. The power output of Axitec panels doesn’t drop below 85% in 25 years.	Average efficiency (15-17%) and lack of innovations.
Low degradation rate: only 0.5% per year while the average number across solar panels is closer to 0.8%.
Affordable price: $0.55 per Watt.

Tatiana Ivanova

Author

With a degree in Linguistics, Tatiana uses her vast experience in technical translation to deliver complicated concepts in simple words. She joined the company in 2020 as a contributing writer to become the person to influence Blog’s development.