Japan Invests in Ultra-Thin Solar Panels to Advance Clean Energy Goals

Japan is accelerating efforts to scale up the development of ultra-thin, flexible perovskite solar panels.These lightweight, bendable panels are especially well-suited to Japan’s mountainous landscape, where land for traditional solar farms is limited.

A significant advantage for Japan lies in its abundant domestic supply of iodine, a key material in perovskite panels. Japan ranks second only to Chile in iodine production, offering a strategic edge in raw material sourcing.

Despite the promise, several hurdles remain. Perovskite panels contain toxic lead, and currently underperform silicon solar panels in terms of power output and lifespan. Nevertheless, with net-zero emissions targeted by 2050, Japan is introducing substantial subsidies to promote adoption. One major initiative includes a ¥157 billion (US$1.1 billion) government subsidy to Sekisui Chemical Co, which is building a factory that will produce enough panels to generate 100 megawatts by 2027—enough to power around 30,000 homes.

Looking ahead, Japan aims to deploy 20 gigawatts of perovskite solar capacity by 2040, roughly equivalent to the output of 20 nuclear reactors. This expansion aligns with national goals to derive up to 50% of electricity from renewable sources by 2040, with solar—both perovskite and silicon—contributing as much as 29%, a significant rise from 9.8% in 2023.

Hiroshi Segawa, a leading expert in next-generation solar technology at the University of Tokyo, emphasized the broad potential:

“To increase renewable energy and reach carbon neutrality, we’ll need to harness every available technology. Perovskite solar panels can be manufactured domestically from raw materials to final installation, offering key benefits for both energy and economic security.”

In contrast to silicon panels, which rely on rigid glass and metal framing, perovskite solar cells are produced by coating materials like iodine and lead onto surfaces such as film or glass, resulting in panels as thin as 1 millimeter and one-tenth the weight of traditional counterparts.

This flexibility allows installation on irregular and curved surfaces, making them ideal for Japan’s geography. Several demonstration projects are already underway. A 46-story building in Tokyo, set to be completed by 2028, will integrate perovskite panels.

Fukuoka city also plans to outfit a domed baseball stadium with the new technology, and Panasonic Corp is working on embedding perovskite cells into window glass.

Yukihiro Kaneko, general manager of Panasonic’s perovskite photovoltaic division, envisions a future where urban windows double as power generators:

“Imagine every window in these buildings generating electricity—it would reduce demand on the national grid and localize energy production.”

However, mass production challenges remain. Current perovskite panels are less efficient than silicon-based systems and typically last only 10 years, compared to 30 years for conventional models. Additionally, lead disposal requires strict regulation.

Still, the technology is progressing rapidly. Some prototypes are now approaching silicon-level efficiency, and durability is expected to increase to 20 years soon, bringing commercial viability closer.

As Japan continues to invest, perovskite solar panels could play a vital role in its clean energy transition, supporting both domestic manufacturing and sustainability objectives.