Yamanashi Prefecture has begun a world-first demonstration project using transparent organic thin-film solar cells installed above grapevines. These lightweight panels transmit sunlight necessary for photosynthesis while simultaneously generating electricity. The stored power is then used at night to illuminate the vines with LED lighting, enhancing grape coloration and quality. The initiative aims to achieve carbon-free, high-value agriculture by integrating renewable energy into viticulture.

The demonstration system has been installed over a vineyard growing the “Sunshine Red” grape variety. Unlike conventional silicon-based panels, the organic thin-film modules are flexible, ultra-thin (0.3 mm), and lightweight (approximately 0.4 kg/m²), allowing sunlight to pass through while generating power during the day. About 6 m² of panels—20 pcs, each 1.0 m by 0.3 m—have been deployed. The generated electricity is stored and reused at night to power LEDs that promote fruit coloration.

According to Governor Kotaro Nagasaki, if the trial proves successful, the prefecture plans to expand the use of organic thin-film solar cells to entire greenhouses. Future plans include using the generated electricity to produce hydrogen for heating, creating an energy self-sufficient, carbon-free agricultural model.

“Sunshine Red,” a cross between Sunny Dolce and Shine Muscat, is known for its high sugar content (around 19° Brix), edible skin, and floral aroma reminiscent of roses or orchids. The demonstration will continue through 2027, targeting commercialization thereafter. While early results are promising, the project still faces challenges in long-term durability and economic viability.

Yamanashi’s experiment represents a pioneering step toward “solar-matching,” a next-generation agrivoltaic concept that harmonizes renewable energy production with crop cultivation. By embracing organic thin-film solar technology, the prefecture aims to enhance both the quality and sustainability of its agricultural output, moving closer to a truly energy-independent, carbon-neutral future.

Expert and Governor Comments:

Professor Yasuyuki Watanabe, Public Suwa University of Science

“This demonstration project aims to achieve both power generation and crop cultivation through the production of ‘Sunshine Red’ grapes. Unlike conventional ‘solar sharing’ approaches, we have adopted a unique concept called ‘solar matching.’ Organic thin-film solar cells are characterized by their excellent color selectivity, reproducibility, light transmittance, and lightweight design. Although sometimes confused with perovskite solar cells, this technology is entirely organic and free of lead and tin, making it a safer alternative. This is the first trial of such technology in fruit cultivation, and while I had some concerns, I’m relieved to see that it appears to be working well. Organic thin-film solar technology holds great promise for the agricultural field, and I look forward to continuing this collaboration with Yamanashi Prefecture.”

Governor Kotaro Nagasaki, Yamanashi Prefecture

“This initiative shows great potential for building a more advanced and sustainable agricultural system. In the case of grapes, the organic thin-film solar cells not only serve as rain covers but also generate electricity used to power LEDs that enhance grape coloration, increasing the fruit’s market value. Ultimately, our goal is to cover entire greenhouses with this technology, use the generated power to produce hydrogen, and utilize that hydrogen for heating—creating a carbon-free, energy self-sufficient agricultural model. Amid rising crude oil prices and other challenges, this approach can provide farmers with a more stable and resilient business foundation. We will continue to move forward step by step toward realizing this vision.”