The PV review: how 2023 became the year of TOPCon

In June, Sunova demonstrated another TOPCon module at the Intersolar Europe event in Germany. While this module has a lower conversion efficiency than the Jolywood modules, with an efficiency of 22.9%, these panels were commercially available at the time of the event, and modules available for commercial use will have a more immediate impact on the global solar sector than those still in the research phase of development.

Then, in November, Tongwei improved on this commercial-scale conversion efficiency record, launching its G12R product line, modules within which have a conversion efficiency as high as 23.1%. This sustained investment in new technology, unsurprisingly, led to sustained growth in module manufacturing capacity, with many of China’s biggest solar developers investing considerably in TOPCon manufacturing.

This is particularly true for Trina Solar, which produced its first 210mm n-type TOPCon modules in January, and launched a new TOPCon cell for use in rooftop PV the following month. In the months since, the company has gone on to set a number of new records for both module sales and financial results, shipping more than 45GW of modules in the first three quarters of the year and generating 31.2% more revenue than in the same period of 2022, and helped set a precedent for new Chinese TOPCon manufacturing across the sector.

Between February and November, Suntech, DMEGC and GCL System Integration all announced or launched new TOPCon manufacturing facilities, with a massive combined annual production capacity of 35GW.

Manufacturing around the world

This commitment to new manufacturing capacity was not only present in China, however, with many solar developers in the rest of the world launching new TOPCon facilities in 2023, as the global solar sector looked to dramatically increase its TOPCon production capacity.

Much of this new capacity is to be installed in the US, as the US solar sector looks to rival that of China’s, and reduce the country’s reliance on importing Chinese modules. In September, Silfab Solar announced plans to build a 1GW TOPCon manufacturing plant in South Carolina, and earlier this month, Canadian firm Heliene invested US$10 million to add TOPCon development to one of its manufacturing facilities in Minnesota.

This is notable considering the US’ reluctance to import modules from China, with data from Ember Climate suggesting that North America is on track to purchase just 0.7GW of Chinese modules this year, compared to 110.5GW of sales on track to reach European solar projects.

Yet Europe has also invested in its nascent TOPCon manufacturing sector, and while this is much smaller than that of China’s, it is another example of the widespread interest in the cells, which have featured prominently in a number of solar markets this year. In February, industry veterans Iberdrola announced plans to build a 0.5GW manufacturing facility in Spain, while German start-up 1Komma5° unveiled plans for a massive 5GW TOPCon assembly plant in Germany, suggesting that TOPCon has become so attractive to potential developers that even new companies are eager to engage rapidly and comprehensively in the sector.

Breaking new ground in sales

Fortunately for the global solar sector, these investments in manufacturing capacity have translated to growth in sales of TOPCon modules. This is of particular note in China, where over 40GW of Chinese modules have been left in European warehouses, as supply of panels has far outpaced demand, and the successful sale of many TOPCon modules could be a sign that the sector will avoid a similar fate.

In the third quarter of this year, Hanersun and Trina Solar both announced TOPCon supply deals for projects in Brazil and China, respectively, and in its end of the third quarter results, Jinko Solar noted that close to two-thirds of its modules sold were TOPCon panels, demonstrating how TOPCon modules have rapidly transitioned from emerging technology to important component of manufacturers’ and developers’ portfolios.

The second half of the year saw similar module sales deals struck in the rest of the world, with Canadian Solar and EDF signing a 7GW TOPCon supply deal in the US and an Indian manufacturer reaching an agreement with Spanish developer Acciona Energia for its projects in Texas, Illinois and Ohio.

The latter deal is of particular note, for both the scale of the agreement reached – 1.5GW of new TOPCon modules suggests the panels will be a key component of both companies’ figures – and its international nature, with a three-nation agreement, separate from the Chinese TOPCon sector, demonstrating how companies in a range of markets have become involved in TOPCon developments this year.

This perhaps offers the most optimism for companies in the TOPCon sector, as the technology is itself an attractive investment, and its manufacture and deployment could prove to be a challenge to the existing order of solar development, which is heavily reliant on China.

Beyond TOPCon

However, if 2023 is to be considered the year of TOPCon, there are concerns that 2024 could see the solar sector move on again, to newer technologies and newer supply chains. In November, Maxeon announced that it would investigate “several companies” for alleged infringements of its TOPCon patents in the US, and while details of this investigation remain sparse, the fact that the technology could be connected to uncertainties over intellectual property, and be challenged on its legal status, will be unlikely to encourage further investment in the sector.

Industry experts have also discussed what technological innovations could come after TOPCon, with the dynamic pace of innovation in the solar sector meaning that few technologies will remain at the forefront of the industry for long. In September, Radovan Kopecek suggested that TOPCon back contact cells will “capture the market” from 2028, as developers look to further refine the technological innovations brought about by TOPCon.

Elsewhere, professor Martin Green told PV Tech Premium that TOPCon cells are just one of a number of popular n-type cells, with heterojunction and interdigitated back contact (IBC) cells among its chief competitors. Green concluded that, while TOPCon could continue to dominate the n-type market for the coming years, IBC cells will “win eventually”, suggesting that TOPCon could ultimately be a stepping stone to more refined technology in the future.

As a result, the successes of TOPCon in 2023, and its uncertain future in the years to come, may not be a particularly unique trajectory for a new solar technology. In a fast-moving industry, where the times between research and deployment are growing ever shorter, and researchers and developers alike are eager to accelerate innovation to meet the world’s looming climate targets, the global solar sector may simply be in a position where a single technology cannot dominate the industry for years on end.