Goodbye to solar panels: Japan finally creates solar cells that don’t need to be flat to w

December 26, 2025

For more than a century, solar panels have always been flat; however, Japan has achieved the impossible yet again. Kyosemi’s Sphelar® reaches a milestone by asking the question of why solar panels have to be flat and then proving that solar panels do not have to be flat. Although the early days of photovoltaics from the 1880s prescribed solar panels that needed to be designed based on the materials sourced for the panels, Japan is opting to be guided by the direction of the sun.

Kyosemi’s Sphelar® is achieving the 140-year-old vision

Back in 1883, solar panels had been built by Charles Fritts by coating a selenium base with a thin metal layer to produce power. While the initial solar panels were pure genius, they tended to be rather rigid. This flat panel was rather lucrative for conditions where the light source was still. The static panel, however, could not fully capture the sun from all directions.

The founder of Kyosemi’s Sphelar®, Mr. Nakata, questioned why all solar panels had to be flat. With this curiosity, it was decided that solar panels could be spherical in shape instead.

The knowledge that sunlight comes from everywhere

When lab tests were conducted, it was found that sunlight comes from all directions and strikes from almost everywhere. This is when Mr. Nakata realized that a solar panel of a spherical shape could harness the sun’s energy better than a flat panel.

In Japan, research was deemed so important that JAMIC (Japan Microgravity Center) was formed, where a former mine shaft had been converted into a research site with a 710-meter tunnel holding a drop facility for microgravity experiments.

Turning the concept of spherical cells into reality

The exploration of JAMIC’s potential allowed Mr. Nakata to question whether molten silicon could form perfect spheres in a weightless environment. To test this, engineers from Kyosemi and JAMIC conducted a test whereby silicon was placed within a vacuum capsule and was left to free-fall from a 500-meter drop shaft. Every moment produced moments of microgravity, allowing silicon to melt and recrystallize. Finally, a smoother silicone shape formed.

While the initial tests produced joy, the test required forming a P-N junction on a curved surface. By relying on Kyosemi’s opto-semiconductor knowledge, the engineers at the company were able to turn the concept of spherical cells into a reality. The earliest prototypes were wired in series and could generate electricity. These spherical panels proved that solar panels didn’t need to be flat. With that, the Sphelar solar panel could capture energy from all directions. The time has come to say goodbye to flat solar panels since tiny photovoltaic spheres show us what the future looks like.

Kyosemi’s Sphelar® did not have an easy pathway forward

Kyosemi’s Sphelar® initial research yielded such favorable results that research could immediately accelerate, and the company was able to open its own Microgravity Laboratory in 1998. The company shortened its name from “spherical solar” to Sphelar®. The company then started supplying sample panels to the industry. While early adopters of the panel were initially skeptical of this new design, they slowly embraced the idea of a spherical solar panel. To date, this company captures the story of a complete change in the solar vision.

In this way, Japan became the first country to explore the concept of a spherical solar panel. Mr. Nakata and the team have shown the world that curiosity and questioning could prove that a concept accepted for so long needed to be turned into a broader vision. In this way, this century’s solar shift began, and Japan’s first-ever photovoltaic sphere was unveiled, providing us with an entirely new way to think of renewable energy.