Japan's First Installation of Chalcopyrite Solar Cells on Building Facades

Background and Overview Tokyu Land Corporation and its wholly-owned subsidiary, Green Factory TFK, are partnering with PXP to conduct Japan's first demonstration experiment of installing flexible thin-film 'chalcopyrite solar cells' on the building facade of 'Techno Farm Keihanna' (Kizugawa City, Kyoto Prefecture), an artificial light-type plant factory operated with 100% renewable energy.

In recent years, the need for plant factories that can achieve stable agriculture regardless of weather has been increasing due to climate change and food self-sufficiency issues. However, rising construction costs and the high electricity consumption required for fully artificial light-type factories have been major operational challenges. This initiative utilizes Tokyu Land's expertise to introduce onsite renewable energy for self-consumption, ensuring stable power supply, reducing electricity costs, and promoting decarbonization.

Advantages of Chalcopyrite Solar Cells The chalcopyrite solar cells adopted are extremely lightweight, weighing 1/10th (approx. 800g/㎡) of conventional panels, and have a thin-film structure (approx. 0.9mm). This feature enables installation on vertical walls and curved surfaces, which were previously difficult for conventional glass-based modules, allowing for the introduction of renewable energy into existing buildings with load restrictions. The installation will use lightweight mounting systems and adhesive methods to shorten the construction period and minimize the burden on the building structure.

Verification Items for the Experiment Scheduled to start in July 2026, this demonstration will verify the following: - Power generation performance (data acquisition by season and orientation) - Weather resistance and aging degradation (durability against wind, rain, UV, and temperature changes) - Impact on building loads (thermal insulation effects and impact on indoor air conditioning loads) - Maintainability (ease of cleaning and inspection)

Carport Solar Power Systems Furthermore, a 36kW carport-type solar power system will be introduced in the parking area on the site of Techno Farm Keihanna, with an expected annual power generation of 45,390kWh. This is expected to achieve a CO2 reduction of approximately 18.8 tons per year, effectively utilize parking space, and strengthen Business Continuity Planning (BCP) as an emergency power source in the event of a disaster.

Future Outlook Following this demonstration, Tokyu Land intends to expand renewable energy implementation across a wider range of building specifications, contributing to the national target of a 40-50% renewable energy ratio in the power source mix by fiscal year 2040, as outlined in the 7th Strategic Energy Plan.