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LONGi Solar Panels: Review

LONGi Solar was founded in February 2000 as Xi’an LONGi Silicon Materials Corporation. The company’s initial focus was on the development and production of single crystal (mono) silicon wafers that are used in many of major solar panels.

After entering PV Module production LONGi have been referred to as the fastest growing PV module manufacturer skyrocketing to an estimated 18GW of production capacity in 2020 (according to Bloomberg NEF) making them the largest Solar Panel manufacturer in the world. Despite this LONGi continues to produce more silicon wafers than solar panels with a strategic goal of reaching a production capacity of 45GW of wafers by the end of 2020.

LONGi’s manufacturing plants are located in China, Vietnam and Malaysia. LONGi Solar Panels have entered the Singapore market and captured a significant portion of market share. LONGi was the only Solar Panel manufacturer to be named as AAA-rated by the PV ModuleTech Bankability Ratings in the Q3 2020 rankings.

What makes LONGi solar panes different – Product Features

LONGi only produces monocrystalline PERC solar panels as they have been focused on producing single crystal (mono) silicon wafers since the early 2000s. LONGi’s modules fit into the mid-tier of solar panels that are high quality but don’t offer 25 year product warranties and a premium price. Generally their panels have higher efficiency due to leading cell technology than their competition at a similar price range.

Monosilicon Exclusively

There are two types of silicon used in the production of solar cells -- polysilicon and monosilicon.

Polysilicon is comparatively easy to make. The molten silicon is poured into a mold and allowed to cool. It's quick, easy, and there's little in the way of waste. Its disadvantage however, is it is made up of multiple crystals of silicon; which impacts on the efficiency of solar cells.

Monosilicon is significantly more difficult to produce and consequently more expensive, but the process results in a single large crystal of silicon, enabling solar cells be more efficient.

LONGi only makes monosilicon and is the world's largest producer -- at least in respect to ingots. They own a massive number of specialised slow cookers called crucibles that bake and rotate at the optimum rate to produce cylindrical ingots of silicon using the Czochralski process. Ingots used for solar cell production are typically 10 to 20 centimeters across.

The crucibles, which reach temperatures of 1,425°C, are usually made from quartz which has a melting point of 1,713°C.

Slower Power Degradation

LONGi Solar Panels retain more power capacity through their lifetime with a warrantied degradation rate of 0.55% per year for the Mono module and 0.45% per year for the Bifacial module compared to a traditional degradation rate of 0.7%. For the Hi-MO4 mono modules this means they will be producing 1.85% more after 10 years and 3.35% more after 20 years. LONGi’s Hi-MO4 has an industry standard 25 years performance warranty and 12 years product warranty.

So, are LONGi Solar Panels a good option for me?

LONGi Solar Panels are a great reliable option for a customer looking for an affordable mid-range panel from a company with a solid financial backing and reputation. Given their size, if your solar installer goes out of business, you have a very good chance of claiming warranty directly from the LONGi as they are the biggest manufacturer in the world.

LONGi Performance Warranty - Better Than Average

Most tier one solar panels at the lower end of the pricing range only guarantee around 80% of their originally rated power after 25 years. But LONGi promises their standard panels will still produce at least 83.1% of their original output after this time and their PERC panels will provide at 84.8%.

With a little luck, other lower cost tier one panel manufacturers will feel confident enough in their engineering to bump up their performance warranties to being them in line with LONGi's.


LONGi solar panels are Tier-1 and reliable. You would not have a problem with installing them on your roof. They will also appeal to people who are interested in panels that should lose little in capacity over the years, but don't want the expense of purchasing premium panels. While many companies have run into financial difficulties after rapidly expanding, LONGi's financial position appears reasonably sound.

If you are considering LONGi solar panels, we recommend them, especially if you are looking for solar panels on a budget without sacrificing on efficiency. In addition to their value based price point, their modules are typically high-watt which adds additional savings due to smaller bill of materials and installation costs. Contact to Solar Era now to get a quote!

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