Why Chinese solar giant Longi’s record-breaking panels will take years to bring down electricity bills

The world’s largest producer of solar panels made headlines last week with a new world record for a product’s energy conversion efficiency
But it will take a while for this achievement to translate to cheaper electricity bills and bolster global climate change efforts, analysts say

Business of climate change

Eric Ng

Published: 9:30am, 25 Nov, 2022

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Longi Green Energy Technology, the world’s largest producer of solar panels, made headlines last week by announcing it has broken another world record for a product’s energy conversion efficiency.

While the news is exciting for scientists and engineers, it will take years for this achievement to translate to cheaper electricity bills for consumers and bolster global efforts to decarbonise energy production and fight climate change, analysts said.

“[It] is really a great achievement, bringing the progress in the industry to the next level,” said Karl Melkonyan, senior solar and clean energy technology analyst at financial information provider S&P Global. “The next notable factor, however, is to stabilise the production cost at a level [viable] for [commercialisation].”

Though Longi is able to produce solar cells using a single production line with a capacity of several hundred megawatts, it will take one or two years to scale up production and reduce costs, he said. A solar panel is an assembly of solar cells mounted in a frame.

The Heterojunction technology (HJT) behind the groundbreaking efficiency needs to be cost competitive against the dominant passivated emitter and rear contact (PERC) and the emerging tunnel oxide passivated contacts (TOPCon) technologies, said Melkonyan.

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Renewable energy – mainly solar and wind – will meet over 70 per cent of China’s additional electricity demand in the next three years as the nation aims for peak coal consumption by 2025 and peak carbon dioxide emissions by 2030 to help fight global warming, according to the International Energy Agency.

Longi’s HJT silicon solar cells have achieved a 26.81 per cent efficiency rate in turning sunlight into electricity, the company said in a statement last Saturday, citing the latest certification report by Germany’s Institute for Solar Energy Research in Hamelin.

In just over a month, its research and development team has broken the world record three times, increasing the efficiency from 26.74 to 26.81 per cent, Longi said.

The previous record of 26.63 per cent was claimed by Japan’s Kaneka in 2017.

Longi’s achievement will be included in the next version of the efficiency tables tracking the industry’s progress, the Shanghai-listed firm quoted Martin Green, known in the field as the “father of photovoltaics”, as saying at a ceremony to announce the record.

The professor at Australia’s University of New South Wales held the record for silicon solar cell efficiency in 30 of the last 39 years.

The PERC solar cell he invented in 1983 accounted for 91.2 per cent of global silicon solar panels produced last year, according to the China Photovoltaic Industry Association.

The conversion efficiency of cells is reduced by 2 to 3 percentage points after they are assembled into panels.

This means future HJT panels are likely to have efficiencies of around 23 per cent, compared to the 20-21 per cent enjoyed by panels sold in the market today, Melkonyan said.

For every percentage point of efficiency improvement, a decrease of about 3 per cent in the electricity generation cost is possible, he estimated.

While more efficient modules are more expensive and would increase the upfront infrastructure costs, this could be more than offset by savings on transportation, installation, operations and maintenance, he added.

However, future cost reduction is hard to predict since manufacturing solar components consumes a lot of electricity, which has become more expensive in the wake of Russia’s invasion of Ukraine, said Frank Haugwitz, founder of the Asia Europe Clean Energy (Solar) Advisory.

Higher prices of the materials used to build solar generation systems, such as aluminium used in support structures and ethylene vinyl acetate (EVA) used to seal the solar cells into panels, have also affected costs, he added.

He expects HJT panels to start making significant market share gains from 2024.

“That means ordinary folks still have to wait a bit longer until such modules will be available,” he said. “Once you cross the 1,000 megawatts [production] scale, you get a feel for mass production.

“Given this is a fairly competitive industry, the transition from workhorse-like PERC towards HJT on a massive scale [will probably] take two to four years.”