LONGi

LONGi Green Energy Technology Co. Ltd. is one of the world’s largest and most influential solar manufacturers, headquartered in China and active across the full photovoltaic value chain. Founded in 2000 in Xi’an, Shaanxi province, the company began as a specialist manufacturer of monocrystalline silicon materials and has since grown into a global producer of solar wafers, cells, and finished solar panels.

LONGi is best known for its focus on monocrystalline technology. Over time, this specialisation helped position the company as a dominant supplier of high-efficiency silicon wafers, forming the foundation for its later expansion into module manufacturing and large-scale solar development.

Origins and early growth

The company was founded in February 2000 by Li Zhenguo as Xi’an LONGi Silicon Materials Corporation. Its early business centred on the research, manufacture, and distribution of monocrystalline silicon ingots and wafers, supplying materials to other solar manufacturers rather than producing finished panels itself.

This upstream focus proved strategically important. As global demand for solar energy increased, LONGi scaled rapidly as a materials supplier, becoming the world’s largest producer of monocrystalline silicon wafers. During this period, the company built a reputation for combining high-volume production with continuous efficiency improvements, breaking multiple industry efficiency records in a short space of time.

Expansion into module manufacturing

A major shift occurred in the mid-2010s as LONGi expanded beyond raw materials into full photovoltaic manufacturing. The acquisition of LERRI Solar in 2014 marked a key step in this transition, enabling the company to move into solar cell and module production at scale.

In 2017, the company formally rebranded as LONGi Green Energy Technology Co. Ltd., reflecting its broader manufacturing scope and its evolution from a silicon materials supplier into a fully integrated solar company. This change also coincided with the removal of the “Xi’an” regional reference from its corporate name, signalling its national and international ambitions.

From this point onward, LONGi became a major global module manufacturer, developing large-scale production facilities and entering international markets across Asia, Europe, and beyond.

Industrial scale and global presence

LONGi’s growth has been driven by large-scale manufacturing investments and vertical integration. The company developed major production sites across mainland China, and later expanded manufacturing into countries such as Malaysia and India. It also acquired facilities from other solar companies, including former SunEdison assets, strengthening its global production footprint.

At the same time, LONGi entered major supply agreements and partnerships, including multi-billion-dollar contracts for panel supply and silicon sourcing. These moves helped cement its position as one of the largest players in the global solar supply chain.

LONGi is listed on the Shanghai Stock Exchange and became part of the “Silicon Module Super League”, a group of the world’s largest crystalline silicon module manufacturers, alongside brands such as Jinko Solar, Trina Solar, JA Solar, Canadian Solar, and Hanwha Q CELLS.

Technology focus and innovation

Technologically, LONGi has consistently focused on high-efficiency monocrystalline solutions. The company has played a major role in the industrial adoption of PERC cell technology and later developments in high-efficiency cell architectures. Its research and manufacturing strategy has centred on improving conversion efficiency while reducing cost per watt at scale.

This emphasis on manufacturing optimisation and efficiency has been central to LONGi’s growth model. Rather than positioning itself primarily as a premium niche brand, LONGi has focused on industrial-scale production of high-efficiency panels for global markets, supplying both residential and large commercial installations.

Regulatory and market challenges

As LONGi expanded internationally, it also faced increasing regulatory scrutiny and market pressures. In the 2020s, the company became involved in trade and tariff-related investigations in the United States and Europe, including rulings and investigations relating to tariff circumvention and state subsidies.

In 2024, LONGi announced significant workforce reductions as part of a broader restructuring in response to global overcapacity in solar manufacturing and intensifying price competition. European regulators also initiated investigations into subsidy practices, reflecting growing geopolitical and economic tensions within the global solar supply chain.

LONGi today

Today, LONGi stands as one of the most significant industrial forces in the global solar industry. It is not just a panel brand, but a vertically integrated manufacturer with deep control over silicon production, wafer manufacturing, cell technology, and module assembly.