This text is a part of the March 2023 version of our publication The Sol SOURCE. Click on right here to learn the complete publication.
The agricultural and photo voltaic industries generally compete for land use, however they’ve not too long ago discovered methods to work collectively. Agrivoltaics is using land beneath photo voltaic panels for crop fields, permitting a web site to provide each meals and power. To raised perceive how these twin makes use of work together, we researched how yields for lettuce, a money crop that may produce in shaded situations, would possibly profit from modifications to photo voltaic panel configuration at a projected rising web site close to Fresno, California. We discovered that some configurations are nicely suited to each agricultural productiveness and mission returns.
Analysis Strategies
Our workforce evaluated 4 system configurations:
- a set ground-mounted system with one-meter floor clearance;
- a set elevated system with 3.75-meter floor clearance;
- a single-axis monitoring ground-mounted system with one-meter floor clearance; and
- a single-axis monitoring elevated system with 3.75-meter floor clearance.
We measured the impact on lettuce yield of changes to ground-clearance peak, array peak, axis choice, tilt, monitoring rotation restrict, and backtracking.
Row spacing was set to roughly 4 meters between panels, permitting lettuce positioning between rows to adapt to plain 14-inch spacing, together with 14 inches from the system’s customary 20-inch-diameter assist piling. The yield was measured below regular and drought situations to observe crop response to variable moisture retention. Decreased moisture retention in drought situations leads to better manufacturing when panels are positioned over the lettuce, enhancing yield for ground-mounted panels and elevated arrays.
Utilizing all enter parameters, we created 25 plots of subarrays containing 20 rows per subarray and 16 modules per row, occupying a complete of seven acres of land. Variations in assumed yield had been calculated primarily based on common photosynthesis. System prices had been adjusted to replicate elevated labor and supplies prices of elevating panels on stilts and putting in trackers.
Outcomes and Conclusion
Whole lettuce output for every system parameter demonstrated that elevating panels is vital to rising lettuce yield. Monitoring additionally will increase yield, though to a lesser extent.
The fee-adjusted monetary outcomes for every array design confirmed that the fastened elevated system generated the very best web current worth, whereas the ground-mounted monitoring system generated the very best inside price of return (IRR).The elevated monitoring system maximized lettuce yield, generated the very best whole revenue, and generated a better IRR than each fastened programs. The one-axis monitoring array with 3.75-meter floor clearance resulted within the smallest discount in lettuce yield in comparison with full-irradiance rising situations. Importantly, an elevated system design would enable tractors averaging three meters in peak to move below the array, permitting farmers to make use of typical harvesting strategies. Unelevated ground-mounted programs would require harvesting by hand, necessitating particular protecting tools for employees working close to the panels.
Additional analysis into the potential of agrivoltaics is crucial to enhancing land use within the clean-energy economic system. Extra detailed knowledge and quotation info can be found upon request.
Endnotes
1. Barron-Gafford, Pavao-Zuckerman, Minor, Sutter, Barnett-Moreno, Blackett, Thompson, Dimond, Gerlak, Nabhan, and Macknick (2019), Agrivoltatics present mutual advantages throughout the food-energy-water nexus in drylands, Nature Sustainability.
2. Tani, Suguru, Nakashima, and Hayashi (2014), Enchancment in lettuce development by mild diffusion below photo voltaic panels, Journal of Agricultural Meteorology.
