Hirasol Energy Co., Ltd has recently completed a successful repowering project at the Oka-no Park Solar Power Plant, Japan’s first 100kW-class solar power plant, originally established by the Yamanashi Prefectural Enterprise Bureau in 1993. This project was part of a joint research effort with the Yamanashi Prefectural Enterprise Bureau and Hyakunen Solar Yamanashi Co., Ltd to verify and test advanced technology.

After 30 years in operation, this aging power station required substantial upgrades to revive power generation.

Instead of a complete system replacement, Hirasol implemented targeted repowering. Following extensive repairs and upgrades, the PV power plant resumed operation on October 1, 2024, with its energy dedicated to self-consumption within Oka-no Park.

Leveraging big data-driven power output simulations, the project identified critical areas for repair to enhance performance. Rather than a full replacement of the solar panels, Hirasol focused on essential updates, including rewiring, upgrading communication components, and replacing the aging power conditioners and high-voltage equipment. This digital approach minimized costs while maximizing output, demonstrating that 100kW-class solar plants can maintain stable energy production and operational value over time.

Notably, this repowering was completed at only a quarter of the cost of a typical new installation of similar scale, representing a significant cost-saving innovation in renewable energy maintenance. This initiative highlights the cost-effectiveness of strategic upgrades and sets a precedent for sustainable solar infrastructure revitalization in Japan and beyond.