LONGi Solar Panels: An Independent Review by Solar Choice

Note: Solar Choice is not a solar installer and has no financial or other incentives to promote any product brand over another.

LONGi Solar – Company History

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 (monocrystalline) silicon wafers that are used in many of the major solar panels brands.

The company now has a total of 10 manufacturing plants producing silicon cells and full solar panels. Eight of them are located in China, and the other two are located in Vietnam and Malaysia. They have also commenced construction on a new facility in India.

LONGi was the only Solar Panel manufacturer to be named AAA-rated by the PV ModuleTech Bankability Ratings in the Q3 2020 rankings. 

As the largest product of solar panels in the world, LONGi was ranked 724th in Forbes’ global top 2000 in 2022.

In Australian, LONGi Solar Panels first came on the scene in 2017 and have since captured a significant portion of the market share. They have established a local Australian office in Sydney to support local customers and installers.

In September 2022, LONGi announced that they had broken the new world record of conversion efficiency of 26.12% for its p-type silicon heterojunction (HJT) cells.

Key Indicators

What is a Bloomberg Tier 1 Solar Panel?

Bloomberg’s infamous tier 1 ranking is NOT a measure of Solar Panel quality in any way. It is simply an indication of the bankability of the manufacturer based on publicly released information on the financial health the company. This should give you an idea if the company is a large, well-known manufacturer.

See full list of Bloomberg Tier 1 Solar Panels

What is PV Evolution Labs Top Performer?

PV Evolution Labs with support from DNV GL independently test solar panel reliability. The tests are voluntary, with solar panel manufacturers paying to participate in the testing. This testing process is internationally renowned and is an accurate reflection of the solar panel’s performance.

LONGi Solar Panels was listed as a top performer for 6 performance tests(damp heat, mechanical stress sequence, hail stress sequence, PID, LID+LETID, PAN performance) in the latest report. Please note that Longi Solar had a large number of different solar panel models tested with varying results.

See full list of PV Evolution Labs Top Performing Solar Panels

Why is office location in Australia Important?

Most solar panel manufacturers entering the Australian market first set up their distribution channels and worry about customer service later. This has led to many unhappy customers who are left trying to contact Chinese head offices to claim on their 10-year product warranty.

Relying on your solar installer is not always an option as we’ve seen many residential solar installers (including the large ones) go out of business well within the lifetime of the systems they are installing. 

LONGi’s Australian office is located in Sydney.

How much do LONGi Solar Panels cost?

Based on Solar Choice’s database we have access to average costs as an indicative guide. The below prices include:

• Full turnkey Solar System with LONGi Solar Panels
• Installation from a pre-vetted reputable installer from Solar Choice’s network
• The STC rebate and GST

 Important Note: Prices will vary depending on location, inverter brand and which installer is used

LONGi Solar Panels – Points of Difference

There are many solar panels out there, what makes LONGi solar panels stand out?

The largest solar panel manufacturer in the world

LONGi’s technological and manufacturing not just focus on solar modules but also on the selling solar wafers and cells to other solar manufacturers. According to data from Bloomberg, LONGi Solar has been at the largest solar panel manufacturer since 2020. 

Their annual production capacity is reported to be 105GW for silicon wafers and 60GW for solar panels Q2 2022. 

Vertically Integrated Solar PV Value Chain

LONGi owns most steps in the vertical supply chain to produce a solar panel including producing ingots, silicon wafers and solar cells. This strategy enables them to keep greater control over the supply and quality of each step of the process.

Many other solar panel brands acquire silicon wafers or solar cells from LONGi and pick up the process from there

LONGi only produces monocrystalline PERC solar panels as they have been focused on producing single crystal (mono) silicon wafers since the early 2000s. Generally their panels have higher efficiency due to leading cell technology than their competition at a similar price range.

LONGi Solar Panel Technologies

LONGi Solar currently has 149 solar panels approved by the Clean Energy Council in Australia under the name “LONGi Green Energy Technology Co Ltd”. This is a requirement to be eligible for the federal STC solar rebate.

LONGi has 3 main series of solar panels: Hi-MO 4, Hi-MO 5 and Hi-MO 6 which have a variety of different options to suit residential, commercial and utility-scale projects.

Hi-MO 4 Series

The Hi-MO 4 series uses gallium-doped silicon cells which improves the solar panels resistance to LID. In simple terms the amount of power the panel will produce will remain higher over time than most other panels with an annual degradation rate of 0.55% per year (typically 0.7%). These solar panels also offer a 12-year product warranty which is in line with most of the options on the market.

Hi-MO 5 Series

LONGi have also increased the working current within the panels to ~13amps (from 11amps in the Hi-MO 4m series) which is better suited to the mainstream string inverters that are available.

This range includes the traditional colours and an ‘all-black’ option like the Hi-MO4 series

The series also offers an ‘all black’ option where the solar cells and aluminium frame are black to offer customers a more aesthetically pleasing solution for their roof. 

Hi-MO 6 Series

LONGi’s Hi-MO 6 series includes four models, each designed to meet different solar energy needs:

1. The Artist: This model is for those who prioritise aesthetics. It features colored panels that blend well with building designs, making solar panels both functional and decorative.
2. The Guardian: Ideal for areas with uneven shading, this model has built-in power optimizers that enhance energy output by adjusting the performance of individual panels according to sunlight availability.
3. The Explorer: Offering solid performance with an efficiency of up to 22.5%, this model provides a reliable solar solution at an economical price, suitable for a broad range of applications.
4. The Scientist: This is the most advanced model in the series, delivering up to 23.0% efficiency. It’s designed to maintain strong performance over time, with a first-year degradation rate of less than 1%. For those needing higher efficiency and enhanced performance, the Scientist is also available in Hi-MO X6 and X6 MAX variants:
   • Hi-MO X6: Improves on the standard features with better durability and slightly higher efficiency.
   • Hi-MO X6 MAX: Offers the higher performance and efficiency in the series, designed for environments requiring maximum energy output.

Common Features Across the Series:

• All-Black Design: All models come in an all-black version, favored for its sleek appearance that complements various roofing styles.

Positioning and Performance:

• The Hi-MO 6 series is positioned as a mid-range option, providing a balance between cost and performance. This makes these panels suitable for various settings, from residential homes to small businesses.

Summary: The Hi-MO 6 series by LONGi is tailored to meet diverse requirements, from visual appeal to high energy efficiency, ensuring a suitable choice for nearly any type of installation.

LONGi Solar Panel Specifications (common modules)

LONGi Solar Panel Specifications (Common Models)

LONGi’s Warranty Offer for Australian Customers

Solar panels in the Australian market come with a performance warranty and a product warranty.

The product warranty is probably the more important one as it covers manufacturing defects and most problems experienced with solar panels. LONGi typically offers 15 years for their product warranty, however some of the Hi-MO 6 panels have a 25 year product warranty – it is important to check the datasheet of what you’ve been quoted. A product warranty of 25-years is quickly becoming the norm in the Australian market.

Looking through LONGi’s warranty documentation, there is a clearly documented process to claim a warranty and adequate remedies available after an assessment has been made. Given LONGi have an Australian office to assist with this process, this is one of the better options available in the market.

The performance warranty for solar panels guarantees a maximum rate at which the solar panel will degrade over time. LONGi’s latest Hi-MO 6 (Scientist) series guarantees that their solar panels will degrade no more than 1% in the first year and then no more than 0.4% for the following 24 years. This gives them a slight edge of many of their competitors who typically offer (2.5% in year 1 and 0.7% thereafter).

Over time we would expect LONGi solar panels to slightly outperform other cost-effective brands, however making a claim against the performance warranty for a residential customer is difficult without high quality monitoring equipment.

Click here to read LONGi’s full Australian warranty document.

Pros and Cons of LONGi Solar Panels

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 established in Australia and are the biggest manufacturer in the world.

Example of a LONGi Commercial Solar Project – Numurkah Solar Farm (Victoria, Aus)

• Date: Q3, 2019
• Type of Application: Utility-scale solar farm
• System Size: 128 MWp

LONGi were selected by as the solar panel manufacturer by French renewable energy producer Neoen. The project features 373,839 ground-mounted solar panels spanning 515 hectares. The farm has long-term supply agreements with the Victorian Government and will power Melbourne’s tram network and Laverton Steelworks.

Read more product reviews from Solar Choice

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Jeff Sykes

CEO at Solar Choice

Jeff has consulted on over 20MW of commercial solar projects, ranging from SMEs to ASX top 100 companies. Jeff has also provided independent advice to 100s of residential solar, battery and EV charging customers across every state in Australia. He holds an MBA from the Australian Graduate School of Management and is an expert in business strategy and financial analysis.

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