Longi Solar solar panels reviews

Based on 38 ratings Aus Ranking

  • 5 star 27
  • 4 star 9
  • 3 star 2
  • 2 star 0
  • 1 star 0

Show ratings from:


The views expressed by reviewers are theirs' alone, and do not necessarily reflect those of Peacock Media Group, which makes no representations as to the accuracy of the reviews. For our full disclaimer and further information, see our Terms of Use and our Review Guidelines.

About Longi Solar, Solar Panels

Longi Solar solar panels review

Longi Solar is a Chinese company that is a tier one manufacturer of solar panels.  They only produce monosilicon panels and may be the largest monosilicon solar panel manufacturer globally.  Their panels come with a 10 year product warranty.  They also have a 25 year product warranty that is considerably better than average.  Longi Solar does not have an office in Australia and so the importer of the panels will be responsible for their warranties.

Longi Solar Production

Longi Solar was the world's fastest growing solar manufacturer in 2016.  They produced 2.34 megawatts of panels during that year, but claimed to have 5 gigawatts of module production capacity at the end of 2016.  Despite this, they only produced they produced just 1.259 gigawatts of panels in the first half of 2017, which was 11% less than in the second half of 2016.  This is considerably less than I would have expected from a company with their claimed capacity, but it seems their output is still at a level for the company to be a new member of the "Silicon Module Super League";  which is the group of now 7 companies that account for around half the world's solar panel production.

To date, most of Longi's production has been used in China, but the firm has been expanding into overseas markets and their panels are becoming more common in Australia.

Company History

Founded in 2000, by 2007 Longi boasted 100 tonnes of monosilicon production capacity - enough for approximately one gigawatt of solar modules these day. In 2007, it was likely less, as silicon ingots were still being cut into the thicker "toast" slices instead of the thinner "sandwich" type silicon ingot loafs they do today. These days, ingots are cut so thin, there's only approximately half a gram of silicon in each solar cell.

Longi shipped 2.5 gigawatts of silicon wafers in 2014, which are slices of silicon ingot before they are turned into solar cells.  2014 was also the year Longi stopped producing silicon ingots and wafers exclusively and expanding into solar panel manufacturing by buying Lerri Solar.

After acquiring Lerri Solar, which had been making solar panels since 2007, Longi continued to produce panels under the Lerri name until early in 2017 when the company rebranded as Longi Solar.  Longi may have held off on the rebranding to ensure panel reliability was up to par before associating the Longi name so closely with them.

From 2014 to 2016 Longi expanded rapidly.  Fortunately this success did not lead to them becoming arrogant and developing a Longi 'tude.  Their current 2017 production does not look like it will exceed 2016 production and it remains to be seen if Longi will resume its rapid growth.

Longi Headquarters

Longi is headquarted in Xian, or Xi'an; which located in Shaanxi Province, but Longi says on its website this city is located in the neighboring Shanxi Province.  Somehow the company confused Shaanxi and Shanxi when writing about themselves in a foreign language.  I can't imagine how that happened.

Longi is headquartered in Xi'an rather than further south near Shanghai where the majority of the world's solar panels are made because they began operations as a silicon manufacturer.  Monosilicon production requires a great deal of electrical energy, so they were founded in an area with access to cheap coal power.  Fortunately, China is taking steps to reduce their coal use and one of them is a massive build out of solar capacity.

Overseas Production

In addition to their Chinese factories, Longi is expanding production overseas.  Longi is constructing a factory in India with the ability of manufacturing 500 megawatts of solar panels annually.  The facilility will the situated in the Special Economic Zone (SEZ) in Sri City in Andhra Pradesh.  The factory will employ 1,000 people, which is a significant number for a 500 megawatt plant these days, but as wages are lower in India compared to China, it's not unusual to be hiring more staff than they would back on their home turf.

Longi has also purchased a facility in Malaysia capable of 500 MW of solar panel capacity a year when complete. The plant will ship in silicon ingots, slice them into wafers, produce solar cells and panels, and then melt all the waste silicon to produce new ingots on site.

Longi Makes Monosilicon Exclusively - No Polysilicon

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 degrees Celcius, are usually made from quartz which has a melting point of 1,713 degrees Celsius.

Longi's Vertical Integration

As Longi produces silicon ingots, wafers, solar cells and solar panels, they are considered a vertically integrated company.  While this provides the company a secure supply of silicon, there is potential that by making the company larger, it becomes more cumbersome and less able to react to sudden changes in solar technology and the market.

Monosilicon = Efficient Panels

As monosilicon enables panels to be more efficient in converting sunlight to electricity than polysilicon, Longi Solar panels have reasonably high efficiencies. Their 60 cell panels, which are likely to be used on Australian rooftops, have efficiencies ranging from 17.4% to 19%.

Longi is a participant in China's Top Runner Program, which is a government scheme with a goal of boosting the efficiency of Chinese solar panels.

Efficiency Record For Mass Produced PERC Cell

Just a few days ago Longi announced they had achieved a new cell efficiency record for mass produced PERC monocrystalline cells of 22.43% (which was subsequently bettered by a competitor just a few days later).  While this is cell efficiency only, panels made from these cells won't perform quite as well, but it is still an impressive development.

Risk Of A Monosilicon-Only Approach

With a sole focus on monosilicon and owning so many dedicated monosilicon crucibles means Longi is potentially running the risk being saddled with a great deal of outdated expensive equipment if there are significant declines in the cost of silicon production using other methods.  However, as solar production is expanding very, very quickly; even if more economical methods do appear, old and new technologies could coexist for a significant period.

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 manufactuers will feel confident enough in their engineering to bump up their performance warranties to being them in line with Longi's.

Warranty procedure for orphaned Longi customers

If you have purchased Longi panels from a solar installer who has since gone out of business, the responsibility for warranty claims shifts to One Stop Warehouse, who are the importer for Longi in Australia. Consult the website for OneStop Warehouse and scroll to the bottom of the page to find the nearest geographical office to contact for warranty assistance. OneStop Warehouse have advised that they will ask affected customers to take photos of the panels, with serial numbers, and to send them through via email. They will then make recommendations for installers that can come out and replace panels under warranty. Labor costs related to replacing the panels are not covered under Longi's warranty.


Longi panels are tier one and so should be reliable.  As a result I would not have a problem with installing them on my 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.  While I don't have any solid evidence, I suspect they will be around for a longi time.  I can feel it in my gut.  Specifically, my longi intestine.

Longi Solar Solar Panel Reviews

Bought From: Solar Central Show additional information
We opted for optimisers as we have shade over our house for 30% of the day, and these solar panels are the best. We have produced solar power every day since we made the switch in May.
Bought From: Track Energy
Show additional information
Seem ok so far.
Bought From: Essential Solar Eastern
Show additional information
Bought From: Sunscape Electrical Show additional information
In the last eight months since our Solar PV system was installed it has generated 6.83 Mega Watt Hours of electricity. We have not had to pay an electricity bill in eight months
Bought From: Essential Solar Eastern
Show additional information
Bought From: Sunscape Electrical Show additional information
Bought From: Essential Solar Eastern Show additional information
Bought From: Sky Power Energy Show additional information
Bought From: Essential Solar North West Show additional information
Bought From: Essential Solar Eastern Show additional information
2 weeks of rain and overcast weather and they still charged the batteries to 99%
Bought From: Green Energy Technologies Townsville
Show additional information
Bought From: Green Solar Show additional information
Bought From: 7Ps Energy Solutions Show additional information
Bought From: Sunrun Solar Show additional information
Bought From: Formula Sun Show additional information
Bought From: Essential Solar North West Show additional information
These are great solar panels coupled with Fronius Primo inverter. Consistent performance for a month now with varied weather. Best output of 35.4kw and worst on a rainy day of 10KW with a East/West orientation.
Bought From: Solar Merchants
Show additional information
No problems at all, best we have achieved on our 10 degree angle is 85Kw, its a 12Kw system with 10Kw inverter
Bought From: JT solar
Show additional information
Bought From: Essential Solar Eastern Show additional information
Bought From: Aussie Hybrid Solar Show additional information
Bought From: Essential Solar North West Show additional information
Great Panels 300 watts per panel, high efficiency
Bought From: Formula Sun
Show additional information
Bought From: Essential Solar Eastern Show additional information
Bought From: Space Solar West Melbourne Show additional information
As above.
Bought From: Expert Electrical Nth Brisbane to Noosa
Show additional information
No problems at all so far.
In combination with the Fronius often produce 30kWh per day from November on.
Bought From: Essential Solar
Show additional information
No problems at all so far - the panels are functioning above our expectations.
Bought From: Essential Solar
Show additional information
still waiting for a power bill lol
Bought From: Green Solar
Show additional information
Bought From: Raw Electrical Qld Pty Ltd Show additional information
Bought From: Helioenergy Show additional information
We had 6 Tigo optimizators installed to 6 panels that may have bee effected by shading - appears to be working fine.
Bought From: Space Solar West Melbourne
Show additional information
Bought From: Essential Solar Show additional information
Bought From: Essential Solar Show additional information
Bought From: Energus Show additional information
Bought From: Essential Solar Show additional information
Bought From: UV Power Show additional information
It is early days (not even a month in) but they are generating lots of juice (22x 300W panels, producing 28kWh on a sunny July Brisbane day).
They look the part, so far so good..
Bought From: Positronic Solar
Show additional information
Longi Solar is performing much better than what I was expecting. Almost all the Tier 1 panels manufacturer give 80% efficiency after 25 years but Longi Solar give 87.7% after 25 years. I bought it purely on their reputation globally, they are also the largest Mono Crystalline panels manufacturer in the world. Their panels looks great with black frame. I am very happy with my decision.
Bought From: Essential Solar
Show additional information

Longi Solar has 1 solar panel in our database

Model Type Size PTC Performance Ratio Californian Approved
 To get your quotes, please enter your postcode: