Project Spotlight｜Above the Rooftops of Oita, Japan: Lightweight Aluminum Mounts Pave the Way for Green Power

In Oita Prefecture, located in northeastern Kyushu, Japan, a rooftop PV plant utilizing Grace Solar's aluminum alloy mounting system has been successfully completed and grid-connected. With professionally tailored mounting solutions and agile local services, Grace Solar has delivered reliable support for rooftop PV applications across this mountainous, hot-spring-rich region. Following grid connection, the plant is expected to generate approximately 136,000 kWh annually, equivalent to saving about 52 tonnes of standard coal and reducing CO? emissions by roughly 130 tonnes per year.

Lightweight Design Adapts to Rooftop Loads

Situated on the alluvial plain formed by the Oita and Ono Rivers, the project's rooftop PV installations are primarily built on commercial, industrial, and public buildings. Grace Solar's aluminum alloy mounts utilize lightweight materials that reduce additional rooftop loads while meeting structural strength requirements, minimizing stress on existing building structures. With multi-point anchoring and flexible joint designs, the system accommodates varying roof flatness, ensuring secure installation across diverse rooftop scenarios.

Enhanced Wind and Weather Resistance

Facing the Seto Inland Sea, Oita Prefecture is influenced by sea breezes, with some areas experiencing mild, low-rainfall climates. Grace Solar's aluminum alloy mounts are made from high-weatherability aluminum materials with specialized anodized surface treatment, balancing strength and salt-spray resistance. Structural design has been validated through dynamic wind load simulations, and critical connections feature integrated anti-loosening and anti-corrosion designs, safeguarding modules during typhoon events.

Modular Design for Efficient Installation

Construction on the project rooftop was constrained by roof layout and limited working space, with a tight installation window. Grace Solar adopted a modular pre-assembly design, minimizing on-site fabrication and significantly improving installation efficiency. Working closely with local Japanese engineering teams—from roof surveys to mount installation—the project strictly adhered to JIS standards and local building codes, ensuring timely grid connection.

The clean electricity generated is fed into the local grid, supporting Oita Prefecture's low-carbon energy transition. From a single rooftop to a replicable solution, Grace Solar has taken a solid step forward in Kyushu. The aluminum alloy mounts on the Oita plain have achieved a precise match between product and scenario. The significance of this project lies not just in grid connection, but in providing a reusable technical template for rooftop PV across Japan's plain regions.