Urban Agriculture and Agrivoltaics at UC ANR’s South Coast Research & Extension Center

September 1, 2026

Guest Author: Grant Johnson, Urban Agriculture Technology Advisor, UC Cooperative Extension

UC ANR South Coast REC Agrivoltaics Trial At-A-Glance

• Location: South Coast Research and Extension Center (SCREC) in Irvine, CA
• Scale & Output: 40 ft × 40 ft solar canopy (~1,600 sq. ft.) generating up to 10 kW
• Setting: Modular installation erected between two 40-foot steel shipping containers over a gravel pad
• Solar Technology: Mirai Solar retractable, semi-transparent photovoltaic (PV) shade screen modules (offering up to 60% shade when fully deployed)
• Crops: High-value specialty culinary herbs (Perilla frutescens / Shiso), shade-loving nursery plants, Kratky hydroponic tub systems, and containerized soilless crops
• Open for Public Visits: By appointment, contact Grant Johnson

At the University of California Agriculture and Natural Resources (UC ANR) South Coast Research and Extension Center in Irvine, a unique field demonstration is proving that agriculture and solar power generation can thrive together. Led by UC Cooperative Extension Urban Agriculture Technology Advisor Grant Johnson, the project explores how dual-use solar infrastructure can serve urban producers and shade-house growers. Because urban farms compete with access to tillable soil, the research focuses on crop performance in aboveground systems, including hydroponics and potted plant media.

Unlike traditional agrivoltaic arrays that rely on heavy, static solar panels mounted on rigid ground posts, this system features Mirai Solar’s innovative, retractable semi-transparent photovoltaic shade screens. Hung suspended by a network of cables, the lightweight screens fold in on themselves like an accordion to retract or extend across the canopy area. Mounted in the 40-foot corridor between two steel shipping containers over a gravel pad, this flexible mechanism allows growers to dynamically manage light exposure for high-value crops below while generating clean electricity.

When fully expanded, the semi-transparent panels provide about 60% shade, matching the light reduction of a standard commercial shade house. However, because the screens are motorized and retractable, growers can pull them back to expose crops to full sunlight as plant needs or weather conditions dictate. This dynamic movement protects the array from inclement weather and high winds while enabling real-time lighting adjustments for the crops below.

Farming-Centric Energy Solution

The project leverages technology developed by Mirai Solar, a company co-founded by CEO Michael Salvador and headquartered in Mountain View, California. Designed specifically for high-value agricultural applications rather than competing with utility-scale solar farms, the semi-transparent PV screens generate roughly 50% of the electricity of conventional solid panels while creating tailored light environments for crops below.

At the South Coast REC site, the 40 ft × 40 ft solar canopy generates up to 10 kilowatts of electricity. This is roughly equivalent to the power consumed by a family of four in a 2,000-square-foot home, and it provides more than enough energy to power all crop production activities on site, rendering the farming operation net-zero.

The two 40-foot shipping containers serve a dual purpose:

1. Structural Support: They anchor the overhead tracking and screen hardware, and are common on many grower sites.
2. Operational Hub: They house power distribution systems, battery storage banks, and farming equipment.

Research Highlights

The primary crop evaluated in the study was shiso (Perilla frutescens), a high-value culinary herb particularly sensitive to light-induced physiological stress. Cultivated using the passive Kratky hydroponic method in standing nutrient solution reservoirs rather than solid media, the trial highlighted how overhead solar panels protected water consumption and plant health of hydroponically grown crops.

• Radiation Stress Mitigation: The semi-transparent PV screen deployment reduced extreme light stress and peak Daily Light Integral (DLI) loading, shielding delicate foliar tissue from intense midsummer solar radiation.
• Volumetric Water Savings: Shading mitigated radiant heat from the surrounding gravel pad, reducing solution evaporation and plant transpiration. At harvest, the Kratky tubs under the PV panels had 13.5% more nutrient solution remaining than the full-sun controls, demonstrating a clear reduction in total crop water demand.
• Enhanced Water Use Efficiency (WUE): The shaded shiso left significantly more water behind in the tubs while achieving statistical the same yield with the full-sun plants, the agrivoltaic treatment demonstrated a statistically significant increase in water-use-efficiency, producing the same total yield using less consumed water.
• Yield Parity & Market Quality: Despite the substantial reduction in total solar radiation, the shaded treatment maintained statistical yield parity with full-sun control plots, while successfully preventing foliar sun scald, leaf lignification, and leaf tip burn.

Scheduled Heat Stress Reduction

While these solar arrays were kept static during the initial study, they are designed to open and close. Future research will test dynamic shading during peak daily heat stress. By allowing direct sunlight in the early morning and late afternoon while shielding crops during mid-day heat, this approach balances solar energy generation with optimal crop protection.

Demonstrating Economic Viability for Urban Producers

As part of the ongoing trial, UC ANR will conduct a thorough economic analysis factorizing equipment costs, maintenance overhead, and energy revenue. By offering local urban farmers a secondary revenue stream through electricity generation while protecting high-value crops from extreme heat and sun scald, this dynamic agrivoltaic system establishes a sustainable blueprint for dual-use land management in Southern California.

Guest Author: Grant Johnson

Grant Johnson is the University of California Agriculture and Natural Resources Urban Agriculture Technology Advisor for Los Angeles and Orange Counties, providing impartial, research-driven insights to optimize plant production in urban environments. With a focus on indoor production, his diverse clientele includes nurseries, commercial growers, school districts, and community gardens. He aims to present research and extension of horticultural topics related to irrigation, plant culture, and agricultural technology such as agrivoltaic system innovations that drive the future of farming, ensuring technological advancements that benefit a wide range of urban farming practitioners.