Assembling a solar powered future in China

Workers in blue jumpsuits and white masks placed clamps around a bar of shiny metal and fed it into a powerful cutting machine. The bar. an ingot made of polysilicon, a heavily refined cousin of the same material that makes up sand. Inside the cutter, it was sliced into thousands of small squares slightly larger than a CD case and thinner than a thumbnail. These wafers would then be shipped on to other factories to be infused with conductive elements such as phosphorous and boron, then wired into cells and assembled into panels—the base unit of solar energy generation. Above, employees manufacture photovoltaic cells on the production line at the Longi Green Energy Technology Co. plant in Xi'an, Shaanxi Province, China.

An employee inspects photovoltaic cells on the production line at the Longi Green Energy Technology Co. plant. Longi Green Energy Technology Co., is the world’s largest producer of solar wafers and the world’s largest solar company by market value.

As of the end of last year it created about 1 of every 4 wafers made anywhere on the planet, and since then it’s announced at least five projects to expand its factories or build new ones.

Despite a pandemic that may slow the growth of new solar power installations for the first time in decades, Longi expects its production capacity by the end of 2020 to have increased by two-thirds compared with 2019. Above , photovoltaic modules stand at a solar power plant co-owned by Longi Green Energy Technology Co. and China Three Gorges Corp. in this aerial photograph taken in Tongchuan, Shaanxi Province.

Plunging costs have left solar the cheapest form of energy in parts of the world. Subsidies are disappearing as it becomes more competitive with other forms of electric generation, making demand less dependent on political decisions.

And advances in energy storage are opening a tantalizing possibility: that solar could, in the near future, replace fossil fuels in many places. “We believe the solar market will maintain the trend of rapid growth,” says Li Zhenguo, Longi’s billionaire president. Above, an employee carries a tray of photovoltaic cells on the production line.

“Current global production capacity, including Longi’s, is nowhere near enough to meet the coming demand.”

Longi dates to a time when Chinese solar manufacturers were relying primarily on cheap labor to undercut more established players from the U.S. and Europe.

There are two ways to make the blocks that solar wafers are sliced from: by cooling molten silicon into one homogeneous structure or encouraging it to crystallize from different points. The first approach, known as mono-crystalline, provides greater conductivity and efficiency.

Longi is trying to avoid their fate by not overextending itself financially. It’s managed to keep a lid on labor costs by boosting productivity, sometimes at the cost of the so-called green jobs that politicians in China and the West love to promote.

At a wafer plant not far from Longi’s headquarters in the ancient imperial capital of Xi’an, producing 350 megawatts’ worth of product required about 1,000 people in 2010. Today its output is equivalent to 6,000 megawatts, with the same number of employees.

Photovoltaic modules stand at a solar power plant co-owned by Longi Green Energy Technology Co. and China Three Gorges Corp. in this aerial photograph taken in Tongchuan, Shaanxi Province. Longi is the world's largest producer of solar wafers and the world's largest solar company by market value.

Solar optimists believe developments such as these might leave the world on the verge of an inflection point. In many places, generating electricity from the sun is now significantly less expensive than doing so from coal or natural gas.