Trina Solar has set a new world record with THBC photovoltaics, a hybrid back-contact cell that exceeds 28% efficiency on a commercial-size crystalline silicon unit.
A new milestone for crystalline silicon
A new world record for solar energy and another milestone for Trina Solar. On April 26, the State Key Laboratory of Photovoltaic Science and Technology (PVST), promoted by the Chinese company, presented an innovative photovoltaic device called THBC, short for TOPCon-compatible Hybrid Back-contact Cell.
The laboratory reported that the cell has already crossed the 28% conversion efficiency threshold on a large active surface.
In the race for the most efficient solar technology, THBC photovoltaics immediately takes a strong position. Despite being relatively new, it promises to compete directly with TOPCon photovoltaics, which has a theoretical maximum efficiency of 28.7%.
But what can be expected from THBC solar cells? And what are the strengths of this technology? To understand that, it is worth taking a step back.
What is THBC photovoltaics?
Unlike traditional TBC cells, or TOPCon Back Contact cells, which use the TOPCon passivation method through high-temperature diffusion, the THBC architecture uses hybrid passivation technology.
More specifically, the unit combines the high-temperature tunnel oxide layer of TOPCon with the amorphous silicon passivation technology used in HJT heterojunction cells. This makes it possible to achieve very low electrical resistance and an extremely high open-circuit voltage.
In both TBC and THBC configurations, all electrical contacts are placed on the rear side, using a back-contact, or BC, design.
“The result is an efficiency of 28.00%, positioning THBC photovoltaics as the new benchmark for single-junction crystalline silicon cells,” the laboratory scientists explained.
The figure was officially certified by Germany’s ISFH, the Institute for Solar Energy Research in Hamelin.
The advantages of THBC photovoltaics
The record was achieved on a rectangular 210R cell, usually 210 mm x 182 mm. This is a format that some of the world’s largest photovoltaic manufacturers have committed to making a standard, and one that makes it easier to exceed the 600 W to 700 W threshold per module.
Achieving such high efficiency on a commercial-size unit, rather than on small laboratory prototypes, means the innovation is already ready for mass production.
The process is also highly compatible with current TOPCon production lines.
Based on the THBC pilot line already in operation, Trina Solar expects standard-format modules, measuring 2382 mm x 1134 mm, to exceed 700 W of power.
For African markets where utility-scale solar, commercial rooftops and distributed energy systems are expanding, higher-efficiency modules could become particularly relevant when land use, installation costs and grid constraints are decisive factors.
When will THBC cells reach the market?
“In the future era of crystalline silicon, Trina Solar will define a new paradigm based on the dual engine ‘TOPCon + THBC’,” said Gao Jifan, Director of the Laboratory and Chairman of Trina Solar.
The company’s strategy will move on two fronts. On one side, it will continue to maximise the potential of TOPCon photovoltaics, including 3.0 and 4.0 evolutions, to leverage the combined advantage of front-and-rear bifacial generation.
On the other, it will accelerate the industrialisation of THBC photovoltaics to capitalise on its higher front-side power, creating added value for customers.
The company says the new generation of THBC cells will be launched soon.
“Trina Solar,” the laboratory website states, “goes beyond the limits of a single-approach model through its THBC structural reconfiguration technology, deeply integrating the multiple technological advantages of TOPCon, HJT and BC. It has not only crossed the 28% efficiency threshold, but will also integrate the multidimensional advantages of high-efficiency power generation, industrial aesthetics and low-carbon environmental sustainability into its future products.”
