Until now, Japanese companies have repeatedly taken the lead in developing cutting-edge innovative technologies, such as silicon solar cells, liquid crystal displays, organic electroluminescence displays (ELDs), and lithium-ion batteries. Nevertheless, they generally seem to find themselves bested by Chinese and Korean companies in the full-scale commercialization phase. 

Today’s commercial solar technology centers around silicon photovoltaic (PV) cells. Almost overnight, China’s solar panel industry grew from a tiny rural-oriented segment in the 1990s to a world-conquering juggernaut. Between 2008 and 2013, China’s solar industry dropped world prices by 80%. 

According to the International Energy Agency, more than 60% of the world’s solar panels are now made in China. At 130 gigawatts, China’s solar energy capacity is also by far the largest in the world. Huge solar farms can be found throughout the country, with one such farm in Xinjiang Province alone covering 33,000 acres.

Japan’s mountainous geography makes it impossible to emulate China in this respect. Moreover, despite their many positive attributes, the solid, opaque layers of silicon make it difficult to use silicon PV cells extensively on building roofs and transparent surfaces such as windows. 

Japan would like to see solar power accounting for roughly 30% of its energy mix by 2040. However it definitely does not want to be dependent on China for its solar energy needs. 

As things now stand, China produces 85% of all solar cells and 79% of the polysilicon used in them. 

However, a next-generation, homegrown Japanese technology may soon upend the solar energy sector. Moreover, it could enable Japan to escape supply chain dependency on China while also decreasing its consumption of fossil fuels. 

In 2009, a Japanese university research team discovered that crystalline-oxidized minerals called perovskites have photovoltaic properties that allow them to convert light into a voltage. Since then, there has been a race among Japanese companies to develop perovskite cells. An additional benefit is that they are 1/15th the weight and 1/20th the thickness of silicon solar panels. 

Perovskites can be printed on glass, sometimes as transparent or tinted composites. Their outdoor durability is estimated at about 10 years. High-rise structures often feature a tremendous number of glass windows that are not amenable to the use of conventional solar panels. However, because perovskite solar cells are incredibly light, they can minimize the burden on buildings. 

One can imagine flexible sheets of perovskite solar cell film could be incorporated into a building’s windows and walls. When that happens, Japan’s densely populated urban areas could be transformed into giant energy-generating zones instead of just energy-consuming zones.

In its quest for carbon neutrality, the Japanese government would like to expand the use of perovskite solar cells. Its goal is to install enough nationwide by 2040 to generate the energy equivalent of 20 nuclear power plants. 

Sekisui Chemical boasts a major global market share in sealing materials and interlayer films. Now, as the leader in the field, the government is providing it with ¥60 billion JPY ($405 million USD) in subsidies to develop perovskite solar cells for commercial use. 

This January, the company established Sekisui Solar Film. Sekisui Chemical has an 86% stake, and the Development Bank of Japan holds the other 14%. It promises to be a groundbreaking initiative for Japan’s renewable energy industry. 

Sekisui Solar Film will use Sharp Corporation’s Sakai plant as its production base. When the production line is up and running in 2027, it will have a production capacity of 100,000 kilowatts. That is enough to provide electricity to 25,000 households. 

By 2030, the company expects production to reach one million kilowatts, equivalent to the output of one nuclear power plant. The production line will make use of sealing technology that Sekisui Chemical developed in liquid crystal manufacturing. 

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Initially, the film-type perovskite solar cells are expected to cost three or four times that of PV silicon solar panels. Therefore, they will be best suited for use in large cities. However, optimizing and streamlining the manufacturing process is also expected to improve cost competitiveness. 

Once mass production begins, the company would like to export its solar film. According to Precedence Research, the global perovskite solar cell market size was estimated at $94.8 million in 2022. It is expected to grow to around $2,479.2 million by 2032. 

Already, Sekisui Chemical has installed perovskite solar cells on its headquarters building in Osaka, at Umekita (Osaka) Station, and at an Expo 2025 Osaka, Kansai bus stop.  

Sekisui Chemical aims to achieve sales of ¥150 to ¥200 billion ($1 to 1.4 billion) for its perovskite solar cell business by 2030. There is, of course, always the possibility that other countries will attempt to beat Japan again at its own game. But Sekisui Chemical President Keita Kato vows to do everything possible to protect his firm’s intellectual property. He believes that its perovskite technology cannot be easily imitated. 

In the end, whether or not perovskite solar cells can be mass-produced at a reasonable cost may determine whether Japan’s manufacturing sector can enjoy a revival. 

One of the most appealing things about perovskite cells from an energy self-sufficiency standpoint is that they use iodine rather than polysilicon. Japan accounts for roughly 30% of the global iodine production. Indeed, Chiba Prefecture alone is responsible for about 80% of the nation’s iodine output. 

A huge natural gas reservoir called the Minami Kanto gas field lies off the coast of Chiba. Iodine-rich seawater has remained trapped deep underneath this field for millions of years. This water contains high concentrations of iodine, almost 2,000 times that in typical seawater.

A lot is riding on whether Sekisui Solar Film manages to overcome remaining technical hurdles concerning things like film width and starts producing competitive products. As company president Futoshi Kawakami recently told The Financial Times, “In the domain of solar energy, this is the last chance to tackle China’s market dominance.” 

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Author: John Carroll