Overview

LONGi Green Energy Technology Co., Ltd., commonly branded as LONGi, is a Chinese photovoltaic technology company headquartered in Xi'an, Shaanxi. Established on 14 February 2000 by Li Zhenguo as Xi'an LONGi Silicon Materials Corporation, the company initially concentrated on the production of monocrystalline silicon materials and wafers. It subsequently expanded across the photovoltaic value chain, including silicon ingots, wafers, solar cells, photovoltaic modules, and the development of solar power projects. LONGi's central strategic position in the solar industry has been its emphasis on monocrystalline silicon. Compared with older multicrystalline technologies, monocrystalline products generally offer higher conversion efficiency and a more consistent platform for large-scale manufacturing. LONGi helped accelerate the adoption of monocrystalline wafers by combining high-volume production, process engineering, and investments in research and development. Its silicon-wafer business became the company's defining activity and made LONGi one of the largest, and at various points the largest, manufacturers of monocrystalline silicon wafers worldwide. The company's expansion was supported by acquisitions and international manufacturing activity. LONGi acquired LERRI Solar Technology in 2014, adding photovoltaic cell and module capabilities and broadening its scope beyond upstream silicon materials. The business also acquired or took over manufacturing assets associated with SunEdison, including a silicon plant in Malaysia. By the late 2010s, LONGi operated or planned manufacturing capacity in mainland China, India, and Malaysia, while serving customers and project markets across multiple regions. In February 2017, the company changed its name from Xi'an LONGi Silicon Materials Corporation to LONGi Green Energy Technology Co., Ltd. The change removed the geographic reference from the corporate name and reflected its wider activities after the LERRI acquisition. The LONGi Solar brand is used for important downstream photovoltaic activities, including solar cells, modules, and related solutions. Its product portfolio has included P-type and N-type monocrystalline silicon ingots and wafers, bifacial solar cells, and the Hi-MO family of photovoltaic modules. Research and development has remained a prominent part of LONGi's public positioning. LONGi Solar reported a 23.6% conversion-efficiency result for a P-type monocrystalline PERC cell in 2018, described in contemporary industry reporting as a new record. The company has also pursued bifacial designs, advanced cell architectures, silicon heterojunction, and other technologies intended to improve energy yield and reduce the levelized cost of solar electricity. Industry rankings and innovation awards have recognized LONGi's work in producing high-quality silicon wafers at lower cost. LONGi is listed on the Shanghai Stock Exchange under stock code 601012. Its growth has tracked the rapid expansion of global solar deployment, but the company has also faced the cyclical risks of the photovoltaic industry, including manufacturing overcapacity, intense price competition, trade barriers, and scrutiny of supply chains and subsidies. In 2023, the United States Department of Commerce determined that Vina Solar, a LONGi subsidiary, had circumvented tariffs applicable to Chinese-made products. In 2024, LONGi announced workforce reductions intended to address excess capacity and changing market conditions, while the European Commission opened an investigation concerning alleged anti-competitive subsidies. These developments illustrate the regulatory and geopolitical pressures affecting major Chinese solar manufacturers. LONGi remains an active global photovoltaic brand whose business spans upstream materials, cell and module manufacturing, and solar-energy project development. Its market identity is built around monocrystalline technology, manufacturing scale, efficiency improvements, and the broader commercialization of renewable electricity.

History

LONGi was founded on 14 February 2000 in Xi'an, Shaanxi, by Li Zhenguo under the name Xi'an LONGi Silicon Materials Corporation. The original business focused on monocrystalline silicon materials and wafers, an area that later became the technological and commercial foundation of the group. As solar photovoltaic demand expanded, LONGi invested in production capacity, process engineering, and research intended to make monocrystalline products more affordable for mass deployment. The company's early identity was closely associated with silicon-wafer manufacturing. Its products supplied downstream photovoltaic manufacturers, and the company became known for combining manufacturing scale with improvements in wafer quality and cost. In 2013, contemporary industry coverage recognized Xi'an LONGi Silicon Materials as an innovative company for supplying high-quality silicon wafers at relatively low cost. LONGi's rapid growth reflected the broader shift in the photovoltaic sector toward higher-efficiency monocrystalline technologies. LONGi broadened its position in the value chain through the acquisition of LERRI Solar Technology in 2014. LERRI, also known as LERRI Photovoltaic Technology or LERRI Solar, provided additional cell and module capabilities. This acquisition helped transform LONGi from a primarily upstream silicon-materials producer into a more vertically integrated photovoltaic company. The downstream business has commonly operated under the LONGi Solar name. In 2016, LONGi entered a reported US$1.84 billion solar-panel sales agreement with SunEdison Products Singapore and agreed to purchase silicon manufactured in South Korea. It also took over a SunEdison silicon plant in Malaysia. These transactions and commercial arrangements supported LONGi's international reach and expanded its manufacturing footprint beyond mainland China. In February 2017, the company adopted the name LONGi Green Energy Technology Co., Ltd. The renaming removed the word Xi'an and reflected the company's broader scope following the LERRI acquisition. LONGi continued to develop products across silicon ingots, wafers, cells, and modules while also participating in solar power-project development. The company announced plans in 2018 for a 5 GW module-assembly plant in Chuzhou, Anhui. The reported investment was approximately RMB 1.95 billion, with construction and commissioning expected to take about 28 months. During this period LONGi also publicized progress in photovoltaic-cell research. In 2018, LONGi Solar reported a 23.6% conversion-efficiency result for a P-type monocrystalline PERC cell, presenting it as an industry record at the time. The company subsequently continued work on bifacial cells, N-type technologies, silicon heterojunction, and other high-efficiency architectures. LONGi has maintained manufacturing activities in mainland China, India, and Malaysia and has served international markets through equipment, materials, modules, and project-related offerings. It has also been associated with the Silicon Module Super League, an industry grouping of major crystalline-silicon module suppliers. LONGi's shares have traded on the Shanghai Stock Exchange since April 2012 under code 601012. The company's later development has taken place amid increasing competition and periodic oversupply in the solar industry. Trade restrictions and government investigations have added regulatory pressure. In 2023, the U.S. Department of Commerce determined that Vina Solar, a LONGi subsidiary, had circumvented tariffs applicable to Chinese-made products. In 2024, LONGi announced a workforce reduction of approximately 30% to respond to overcapacity and market conditions. The European Commission also opened an investigation into alleged anti-competitive subsidies involving LONGi. Despite these pressures, LONGi remains an active global photovoltaic manufacturer focused on monocrystalline silicon, advanced cells, modules, and solar-energy deployment.

2024
Workforce reduction announced
[1]LONGi - Wikipediaen.wikipedia.org
LONGi announced plans to reduce staffing by approximately 30% in response to excess capacity and market pressures.
2023
U.S. tariff-circumvention determination
[1]LONGi - Wikipediaen.wikipedia.org
The U.S. Department of Commerce determined that LONGi subsidiary Vina Solar had circumvented tariffs on Chinese-made products.
2018
Chuzhou module-plant plan announced
[1]LONGi - Wikipediaen.wikipedia.org
LONGi announced plans for a 5 GW module-assembly facility in Chuzhou, Anhui.
2018
P-type PERC efficiency result reported
[1]LONGi - Wikipediaen.wikipedia.org
LONGi Solar reported a 23.6% conversion-efficiency result for a P-type monocrystalline PERC cell.
2017
Corporate name changed to LONGi Green Energy Technology
[1]LONGi - Wikipediaen.wikipedia.org
The company changed its name from Xi'an LONGi Silicon Materials Corporation to LONGi Green Energy Technology Co., Ltd., reflecting its broader business scope.
2016
SunEdison commercial and manufacturing expansion
[1]LONGi - Wikipediaen.wikipedia.org
LONGi signed a major panel-sales agreement with SunEdison Products Singapore and took over a related silicon manufacturing facility in Malaysia.
2014
Acquisition of LERRI Solar
[1]LONGi - Wikipediaen.wikipedia.org
LONGi acquired LERRI Solar Technology, expanding from silicon materials into photovoltaic cells and modules.
2012
Shanghai Stock Exchange listing
[1]LONGi - Wikipediaen.wikipedia.org
LONGi Silicon began trading on the Shanghai Stock Exchange under security code 601012.
2000
Company founded in Xi'an
[1]LONGi - Wikipediaen.wikipedia.org
Li Zhenguo founded Xi'an LONGi Silicon Materials Corporation on 14 February, initially focusing on monocrystalline silicon materials and wafers.

Products and positioning

A vertically integrated, research-driven photovoltaic manufacturer positioned around monocrystalline silicon technology, high-volume production, module efficiency, and lower-cost solar power deployment.

Silicon materials
Monocrystalline silicon ingots
Large cylindrical or related forms of high-purity monocrystalline silicon used as the upstream feedstock for photovoltaic wafers. Ingots are sliced and processed into wafers for solar-cell production.
Photovoltaic materials
P-type and N-type monocrystalline silicon wafers
Thin semiconductor wafers cut from monocrystalline silicon ingots and supplied to cell manufacturers. LONGi's wafer business has historically been central to its market position, with product development spanning both P-type and N-type technologies.
Solar cells
Bifacial photovoltaic cells
Cells designed to generate electricity from light received on both the front and rear surfaces. Bifacial designs can increase energy yield in suitable module configurations and project environments.
Photovoltaic modules
LONGi Solar photovoltaic modules
Finished solar panels assembled from photovoltaic cells and supporting electrical and structural components. LONGi's module portfolio has included monocrystalline and bifacial products for utility-scale, commercial, and other solar installations.
Photovoltaic modules
Hi-MO module family
A branded family of LONGi photovoltaic modules associated with higher-efficiency monocrystalline cells, improved power output, and applications ranging from utility-scale projects to distributed generation.

Controversies

2024
European Commission subsidy investigation
The European Commission initiated an investigation into alleged anti-competitive subsidies involving LONGi.
Source
2023
Vina Solar tariff-circumvention determination
The U.S. Department of Commerce ruled that Vina Solar, a LONGi subsidiary, had circumvented tariffs applied to Chinese-made solar products.
Source
2020
German court rules against LONGi subsidiary in Hanwha patent case
The Düsseldorf Regional Court ruled that LONGi Solar Technologie GmbH infringed a Hanwha patent. The ruling barred sales of the products at issue in Germany and ordered their recall from commercial customers, among other measures. LONGi said it would appeal.
Source
2020
German court issues provisional enforcement order affecting LONGi Solar products
LONGi Green Energy Technology said it received notice of a provisional enforcement order from the Düsseldorf Regional Court. The order requires its subsidiary LONGi Solar Technologie GmbH to stop offering, placing on the market or using products related to the patent technology in Germany, destroy relevant products in its possession, and notify commercial customers to recall them. Hanwha had applied for provisional enforcement after paying a €750,000 security deposit.
Source

Brand decisions

2024
Reduce workforce in response to overcapacityStrategy
Background
The photovoltaic market was experiencing manufacturing overcapacity and intensified price competition.
Action taken
LONGi announced plans for an approximately 30% reduction in staff.
Aftermath
The announcement indicated a cost and capacity adjustment, but the supplied reference does not provide a later assessment of its results.
Source
2018
Plan a 5 GW Chuzhou module facilityProduct launch
Background
Growing photovoltaic demand and LONGi's downstream expansion created a need for additional module-assembly capacity.
Action taken
LONGi announced plans for a module plant in Chuzhou, Anhui, with planned capacity of 5 GW.
Aftermath
The plan represented continued investment in downstream module manufacturing, although the supplied reference does not document the facility's eventual operating outcome.
Source
2017
Rename the company as LONGi Green Energy TechnologyStrategy
Background
The company's activities had expanded beyond the geographic and product scope implied by its former name.
Action taken
LONGi removed the Xi'an reference and adopted the name LONGi Green Energy Technology Co., Ltd.
Aftermath
The new name better represented the company's wider manufacturing and solar-energy activities.
Source
2014
Acquire LERRI Solar TechnologyM&A
Background
LONGi was primarily identified with monocrystalline silicon materials and sought to expand into downstream photovoltaic manufacturing.
Action taken
The company acquired LERRI Solar Technology, adding cell and module capabilities.
Aftermath
The acquisition contributed to LONGi's transition toward a broader, more vertically integrated solar business and preceded its 2017 corporate renaming.
Source

Recent events

2024
LONGi announces workforce reductions amid photovoltaic overcapacity[1]LONGi - Wikipediaen.wikipedia.org
Leadership change · Other
LONGi announced plans to reduce its workforce by approximately 30% as it sought to address excess manufacturing capacity and difficult market conditions.
2018
LONGi plans a 5 GW module plant in Chuzhou[1]LONGi - Wikipediaen.wikipedia.org
Product generation · Other
LONGi announced plans for a large module-assembly facility in the Chuzhou Economic and Technological Development Zone in Anhui, with reported investment of approximately RMB 1.95 billion.
2016
LONGi signs major solar-panel supply agreement with SunEdison Products Singapore[1]LONGi - Wikipediaen.wikipedia.org
M&A · Other
LONGi entered a reported US$1.84 billion solar-panel sales agreement with SunEdison Products Singapore and agreed to purchase silicon produced in South Korea.
2016
LONGi takes over SunEdison silicon manufacturing assets in Malaysia[1]LONGi - Wikipediaen.wikipedia.org
M&A
As part of its international expansion, LONGi took over a Malaysian silicon plant previously associated with SunEdison.