Inside the UC Davis Agrivoltaics Demonstration Site
By Benjamin Narwold, contributing author
University of California Davis Agrivoltaics Demonstration Site At-A-Glance
- Size: 9 Acres
- Scale: 448 modules totaling 200.44 kW
- Configuration: Three test systems: 1) Vertical Bifacial, 2) Single-Axis Tracking (two different types), 3) Transparent, Fixed-Tilt
- Interconnected: Yes - interconnection is confirmed for April 3, 2026
- Electricity use: Behind-the-meter
- Open for public visits: For special events, by invitation
At the University of California, Davis, researchers are exploring a fascinating idea: what if farmland could provide multiple outputs, producing both food and renewable energy? Research at the UC Davis agrivoltaics demonstration site, led by Professor Majdi Abou Najm from the Department of Land, Air, and Water Resources, is turning that question into real-world experimentation. Agrivoltaics, which integrates agriculture and solar by maintaining productive farmland below or between panels, is a promising approach in California, where land is limited, water is scarce, and the demand for renewable energy is growing.
The 9-acre demonstration site integrates solar panels with crops including peppers, tomatoes, and basil, enabling researchers to study how light, temperature, and water availability vary across different solar configurations. For example, one research focus is photosynthetically active radiation (PAR), the portion of sunlight plants use for photosynthesis. Solar panels create partial shading, redistributing light across the crops and altering the total PAR each plant receives over a day, referred to as the daily light integral (DLI), which impacts both crop quality and quantity. (Check out our post on these and other common agrivoltaics terms here.)
Photography: Jael Mackendorf, UC Davis.
Exploring Agrivoltaics System Designs
The UC Davis site features four agrivoltaics systems with three distinct solar photovoltaic (PV) designs, each offering unique insights into crop compatibility and energy generation:
- Vertical Bifacial: With panels mounted vertically to capture sunlight from the east and west, this system produces energy primarily in the morning and late afternoon, when electricity demand is highest. Its design offers easy access for farm equipment operating between the rows, providing a minimal-intervention option for farmers.
Photography: Maximilian Dedden
- Single-Axis Tracking: Two trackers that follow the sun throughout the day to maximize energy production are installed side by side, providing UC Davis researchers an opportunity to directly compare crop growth impacts of different technologies. One tracker uses a continuous torque-tube row designed for more uniform terrain (as shown below), while the other uses an articulating, terrain-following structure that can create different shading patterns. For a deep dive into the how and why behind different approaches to solar trackers in general, check out this video.
Photography: Maximilian Dedden
- Transparent, Fixed-Tilt Panels: These semi-transparent solar panels let sunlight pass through while generating electricity, and their spectrally selective coatings enable testing of how different wavelengths affect crop growth, water-use efficiency, and overall land productivity. An important consideration when selecting solar modules is UL listing, meaning they’ve been successfully tested against current harmonized international safety standards and therefore qualify for interconnection. The modules used at the Davis site, shown below, are UL1703 rated, have been approved for and used in interconnected projects for a few years now.
Photography: Maximilian Dedden
Each of these systems creates its own microclimate, or localized growing conditions beneath the panels. By changing the light reaching the ground and airflow through a field, solar panels can influence temperature, humidity, and soil moisture. These changes also affect water loss through evaporation from soil and transpiration from plants, together known as evapotranspiration (ET). Partial shading from the panels can insulate crops against heat stress and substantially reduce irrigation requirements.
Building on Earlier Research
This current work builds on earlier research conducted by Dr. Abou Najm and his team in 2022. That research, which produced findings published in Energy Nexus in March 2026, focused on understanding feasibility and potential of spectral-selective agrivoltaics systems. The research conducted over one May-to-September growing season looked at the impact of two spectrally selective shading scenarios on tomatoes - as compared to those grown in a full-sun control plot. The findings point to the importance of understanding trade-offs and contextualizing information for landowners and farmers considering agrivoltaics. While the experimental shaded plots saw a 33-42% decrease in crop yield as compared to the full-sun control, the water-use efficiency in those plots increased 10-13%.
This increase in water-use efficiency means that researchers were able to produce more crop mass (kg of tomato) with the same volume of irrigation (mm of water) when under the spectrally-selective shade structures versus in full sun. As the professor shared in a July 2025 episode of Clean Power Hour, it’s important to look at the complete picture of food, energy, and water when doing the math on agrivoltaics. Accounting for water spending savings and added energy revenues, crop yield reductions may be considered acceptable when agrivoltaics can provide an alternative to taking land out of production.
Paving the Way for a Sustainable Agriculture Future
In addition to active scientific research, the UC Davis site serves as a hub for interdisciplinary learning and a see-it-to-believe-it example of what’s possible. Agrivoltaics combines agricultural science, solar energy engineering, and economics to inform real-world projects. Researchers in California and across the globe are experimenting with solar PV designs to optimize both crop yield and electricity generation while minimizing development and operational costs.
Ultimately, the UC Davis agrivoltaics demonstration site is more than a research plot. It is helping create a blueprint for agrivoltaics and sustainable dual use of land in California. By integrating crops with carefully designed solar PV systems, the project demonstrates how farms across the state can implement agrivoltaics to achieve long-term economic and environmental benefits amid increasing market volatility and climate variability by harvesting the sun twice for both food and renewable energy production. For the latest insights from this research and to hear from others in the growing agrivoltaics movement, register to attend the 4th California Germany Agrivoltaics Conference happening at UC Davis in November.
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Contributing Author Benjamin Narwold holds a BS in Environmental Science and Management from UC Davis and is focused on advancing sustainable land use at the intersection of agriculture, renewable energy, and biodiversity conservation.