Volume 58

Optimizing Fixed-Tilt Agrivoltaic System Design for Lowland Rice Across Japan Hideki Nakata, Seiichi Ogata

Abstract

Agrivoltaic systems (AVSs) provide a promising strategy to reconcile Japan’s competing land demands for renewable energy and food production. Yet the spatial distribution of AVS designs that reflect the country’s pronounced climatic diversity remains poorly quantified. This study performed a nation‑wide optimization of fixed‑tilt, elevated AVS designs for lowland rice cultivation by coupling 1‑km MONSOLA‑20 monthly radiation data with a computationally efficient crop‑light model. For every one of 376,871 grid cells we identified the projected ground coverage ratio (pGCR) that balances power production and agricultural environmental impacts. The resulting optimal pGCR averaged 20.33%, yielded an average land‑equivalent ratio (LER) of 1.64, demonstrating significantly higher land productivity compared to conventional separate production systems. The resulting AVS design map offers location‑specific guidance for growers, developers, and policy‑makers, thereby facilitating the responsible expansion of AVSs and the formation of resilient urban‑rural food‑energy partnerships in Japan.

Keywords agrivoltaics, agrophotovoltaic, spatial analysis, crop light model, lowland rice, land equivalent ratio