Crystalline silicon cell-manufacturer Tongwei Solar is pushing into automation to help it target rapid growth in offshore markets, writes Jeremy Chunn.

The rapid rollout of solar around the world has fueled fierce competition among module manufacturers, all vying for the attention of developers, system designers and installers. All of those millions of PV panels rely on one primary ingredient – solar cells – and one company with a commanding view over that market is China’s Tongwei Solar, which has been undergoing a rapid expansion of its own.

With two manufacturing bases across China processing about 80,000 tonnes of silicon to produce 20GW of crystalline silicon cells in 2019, the company has set its sights on expansion to 30GW in 2020.

As polluting generation sources are replaced by renewable resources, every manufacturer of clean energy technology knows that investment in research and development is everything. The company has 207 patents and 31 software copyrights, and Tongwei Solar (Chengdu) general manager Alan Xie says the company’s presence in Chengdu allows it access to universities and colleges in the Sichuan Province. “It is an important advantage for private enterprises to attract talent,” Xie says. “For recent years, our annual R&D investment takes up 3%-5% of our sales volume in general.”

The company cooperates with domestic and international institutions and universities in R&D, Xie says, including the Micro-system Institution of Chinese Academy of Sciences. “We do the research on new-type cell technology together, preparing for the next-generation mainstream technology.”

The company supplies module-makers Jinko, GCL, Canadian Solar, Trina, Suntech, Risen Solar and many others.

The partially automated production lines in the Chengdu plant can produce two millions cells a day.

Production line

The 3.8GW-capacity plant in Chengdu EcoGeneration visited in December – Phase IV – was built in just seven months, and the partially automated production lines can produce two million cells each a day. During a tour of the plant a media group was guided through the process that sees mono and poly wafers transformed into single-sided and bifacial PV cells, starting with texturing, where surface area is optimized by way of transformation into tiny pyramids, to diffusion, addition of the p-n junction, etching, screen printing, sintering and current injection.

The Phase IV extension of the plant features 16 unmanned production lines. The company hopes it will be the first 10GW solar cell production base globally and help it reach 30GW capacity from its three manufacturing centres in 2020.

The shift to automated manufacturing has been carefully planned. “First, we started from the automation of equipment, and then we moved on to the automation of a single production line or even an entire workshop,” Xie says. “In the meantime, we also had collaboration with local equipment suppliers and automation integrators, to finally have our intelligent workshop today.”

Tongwei Solar (Chengdu) general manager Alan Xie says R&D investment takes up 3-5% of annual sales volume.

Fisheries opportunity

TW Solar parent Tongwei Group is also a major feedstock company, and its interest in aquatic feed have seen it install solar farms over fisheries that produce breeds that prefer shadowy water, such as silver carp and bigmouth carp. Fisheries are big business in China, as a growing middle class includes more protein in its diet. Rapid development in the Middle Kingdom has seen river fish populations fall, as breeding behavior is disrupted by hydroelectric projects and overfishing.

“With clean energy generated above the water surface, safe and healthy aquatic products under the water, a double-green development is formed,” says Xie.

Tongwei Group has relations with thousands of farmers across China, established over nearly 40 years in the feedstock game. “We started to research the way of utilizing aquaculture resources in 2013,” he says. The company’s “fishery-solar integrity” program has shared benefits, he says: good farming turnout and reduced cost of energy.

“It is a highly-efficient comprehensive utilization of the land. The mode helps to save a lot of resources, as PV solar projects usually require large pieces of land, while in the ‘fishery-solar integrity’ mode, water surface above fishing farms is utilized to generate power, reducing land resources needed.”

Remote system monitoring allows a minimum of personnel onsite and drones are used to report issues in real time.

Looking offshore

The company is targeting foreign sales for its cells of 20% this year, which will see it focus on regions with mature module production industries such India, South Korea, Japan and Vietnam. “These will be major markets we pay attention to,” says Tongwei Solar head of marketing and sales Michael Ao.

South America, including Brazil and Mexico, is also a key market, he says. “We see opportunities of growth in terms of cells there.” In the past Tongwei considered establishing plants in India or the US but suspended the plan over the challenge of local laws and regulations.

The withdrawal of solar subsidies in China came as a shock to the industry, but the clean energy sector is mature enough to adapt to rapid change. “We think there is still a long way to go in China, especially from [2020] on when the subsidies will be cancelled gradually,” says Xie.

Researcher BloombergNEF expects China to install 37-45GW of utility-scale solar in 2020, up from 26-31GW in 2019.

“Although China has made a lot of noise on subsidy-free solar plants – actually plants built under what is effectively a feed-in tariff set at today’s coal-fired power price – 2020 will be the first year to see them hitting the ground in volume,” the analyst said in a report late last year.

A lack of grid capacity will continue to limit China’s solar build, but BNEF expects China to begin to resolve the problem of the National Renewable Energy Fund, which does not collect enough money from power sales to pay subsidies to projects already built. “There are more than 135GW of solar projects commissioned after May 2016 in China that have not yet received any subsidy.”

The world is banking on China to replace dirty generation with wind and solar as quickly as it has built a stunning high-speed rail network. In the meantime, solar developers and installers rely on the country to produce cost-effective and reliable PV technology.

“The global market is on a rise in general,” says Xie. “Especially in some developed countries, the cost of solar power is even lower than those of the traditional means. There is great potential in it, so we think that in the coming years, the overseas market will play an important supporting role in the industry.”