Potential of sugar beet (Beta vulgaris) and wheat (Triticum aestivum) production in vertical bifacial, tracked, or elevated agrivoltaic systems in Belgium

Agrivoltaic (AV) production systems combine renewable energy- and crop production. Two arable agrivoltaic pilot sites with vertical, horizontal, and tracking setups were constructed in Belgium between 2019 and 2022. Field trials for sugar beet and wheat production were conducted for two consecutive seasons. Beet grown in between vertical or tracked AV systems achieved a reduced average yield of 11–19% for the cultivation area, with a land-loss of 11%, and an electricity yield of 376–560 MWh/ha across two seasons. Although leaf pigments for AV-grown plants were reduced, suggesting crop adaptation to shade, yield was likely also affected by soil compaction during construction. A land equivalent ratio (LER) of 1.00 and 1.18 for the vertical system and 1.17 and 1.22 for the tracked system were recorded in 2021 and 2022, respectively. Wheat was cultivated under an elevated horizontal AV system in 2022 and 2023. Yields were reduced by 33% in 2022 and 46% in 2023 in addition to 8% land loss. However, grain quality, protein content and plant morphology remained similar between the AV and control plots. The AV system achieved a LER of 1.09 in 2022 and 0.97 in 2023. Our findings suggest that, despite practical challenges such as construction impact on crop yield, open-field agrivoltaics can attain a slightly net positive LER under the temperate maritime climate in Belgium, providing opportunities for renewable energy generation on arable land. Nevertheless, a careful AV system design and construction is crucial to achieve an economically and agriculturally profitable system.