Off-Grid Agrivoltaics

The demonstration site is located at the Arava Institute in southern Israel, a hyper-arid desert region characterized by extreme heat, minimal annual rainfall, saline soils, and high evapotranspiration rates. These conditions make agriculture highly resource-intensive and create a strong dependency on energy for irrigation, cooling, and monitoring technologies. At the same time, the rapid expansion of solar energy in desert regions raises critical questions about land-use trade-offs, ecosystem integrity, and the potential for co-locating renewable energy with productive land uses.

The demonstrator aims to test how a decentralized, off-grid agrivoltaic system can enhance the Water–Energy–Food–Ecosystems (WEFE) Nexus in a hyper-arid desert environment. The project seeks to:

• Energy–Water Nexus: Use an independent solar-powered system to run precise irrigation systems, cooling storage, cooling adjunct greenhouse, sensors, and microclimate monitoring, showing how remote agricultural sites can operate reliably without grid access.
• Water–Food Nexus: Improve irrigation efficiency through scheduled drip irrigation, and sensor-based monitoring of soil moisture, plant stress, and microclimate conditions.
• Ecosystems Nexus: Evaluate how combining PV structures with detached-substrate vegetation (edible crops, medicinal plants, and desert species) can enhance microclimate stability, ground cover, biodiversity, and other ecosystem services under ground-mounted solar arrays.
• Land-use Synergy: Demonstrate how areas allocated for renewable energy production can maintain agricultural and ecological functions rather than becoming biologically inactive.

Short-term goals focused on installing and optimizing the off-grid system; long-term goals include producing a replicable design for agrivoltaics systems suitable for arid regions and renewable-energy land-use transitions.

This project establishes a two-phase Agrivoltaics (APV) research platform in the Southern Arava, Israel, developed in collaboration with the University of Arizona to generate applied knowledge for arid-climate APV and to ultimately transfer insights to community-managed systems in Kenya. The project’s origin (Phase I) prompted the Israeli PI to critically reflect on Israel’s rapid expansion of solar fields, which has often replaced active agricultural land, altering surface hydrology, reducing pollination and habitat areas, and diminishing local food production. To address these challenges, Phase II led to the construction of a ground-mounted facility that replicates the conditions of a standard solar field. The ground site enables systematic testing of alternative agrotechnical approaches—detached substrate beds, small-scale robotics suitable for confined spaces, smart irrigation control, and polyculture strategies to improve food security and biodiversity within existing solar infrastructure.
Both sites are designed to explore APV configurations that integrate food, water, and energy production without displacing agricultural functionality.

Phase I involved installing an elevated APV system composed of four identical 6×8 m metal–bamboo frames, raised to 3 m and arranged in a checkerboard layout to provide 50% alternating shade. This phase established baseline microclimate, vegetation, and PV–crop interaction data for arid conditions and formed the foundation for subsequent system development.

Phase II expanded the research to include a ground-mounted 5 kW off-grid APV system that simulates the spatial and operational constraints of standard solar fields in Israel. The facility consists of three rows of four bifacial panels (1 m clearance, 5 m inter-row spacing) integrated with a drainage lysimeter array. Eight lysimeters were installed across shaded and unshaded zones—four beneath or near panel shade and four in the open inter-row area—with a 10 cm rockwool drainage layer to support high-resolution analysis of soil–water dynamics. 

Both phases followed a structured implementation sequence (a detailed description of the steps will appear below):

(1) Installation of the off-grid energy system.

(2) Preparation of vegetation beds for edible, medicinal, and desert species.

(3) Connection of the irrigation system and establishment of water-scheduling protocols.

(4) integration of sensors and environmental monitoring systems; and

(5) Initiation of ecosystem-services monitoring in the ongoing research phase.

The project is led by a core team of two researchers supported by 1–2 interns per academic semester. Situated within the Arava Institute’s active research and demonstration area, the facilities engage several hundred visitors annually through training sessions, professional tours, and educational programs. Designed as an evolving platform, the site continues to integrate new variables, interface with broader WEFE nexus studies, and support cross-border collaborations with regional and international research partners.

Technical WEFE Nexus System Installed:

• Deployment of an entirely off-grid 5kw solar PV system powering an irrigation system, cooling system in adjacent greenhouse, and monitoring equipment.
• Integration of a battery system to enable nighttime or low-light operation.
• Installation of microclimate monitoring sensors (e.g., temperature, humidity, soil moisture, PAR sensors) that support data-driven irrigation and plant management.

Agrivoltaics and Vegetation Design

• Construction of a pilot Agrivoltaics structure simulating a ground-mounted solar field.
• Establishment of vegetation beds using detached substrates to cultivate a mix of edible plants, medicinal species, and native desert vegetation.
• Comparison of vegetation performance under different shading intensities (under panels vs. between rows).

Water and Irrigation Management

• Installation of a solar-powered drip irrigation system optimized for minimal water use in extreme desert conditions.
• Testing water-saving scheduling strategies supported by real-time monitoring.
• A drainage lysimeter system was built in the inter-row space. Cumulative drainage is collected in a container, removed, and measured every 4-7 days to calculate accurate evapotranspiration and adjust irrigation cycles.

Soft Components & Capacity Building

• Hands-on training for Arava Institute students, visiting delegations, and local practitioners on nexus thinking, solar-water management, and Agrivoltaics operation.
• Demonstration tours for policymakers, NGOs, and professional groups.
• Collaborative experiments with institute researchers and interns. 

Water

• Demonstrated water savings through partial shading and controlled irrigation scheduling, and early indications of reduced evaporative losses in shaded zones.

We found consistent increases in soil water under PV panels across all crops and seasons, indicating potential for water conservation. Directly measured water balance at 70% shade from PV showed a ~50% reduction in water requirements. 
Our results indicate a 20-40% reduction in daily water requirements in most crops, which can accumulate to save 1000-2000 m³/Ha of irrigation water over an entire season. 

Energy

• Stable off-grid power production supporting adjacent greenhouse cooling systems.
• Microclimate cooling from vegetation reduced module temperatures by up to ~8°C at midday, with short-term improvements in panel efficiency on some days.
• Real-time monitoring improves operational reliability and system transparency.

Food and Vegetation Production

• Establishment of detached-substrate crop beds for growing edible and medicinal plants under controlled conditions in a hyper-arid environment.
• Plants beneath or adjacent to the PV structures experienced reduced canopy temperature by ~4°C on average, lowering heat stress during peak hours.
• Growing seasons 2021–2025 produced a multi-year dataset covering tomatoes, green onions, lettuce, radish, spinach, kale, sweet potato, corn, basil, and kohlrabi.

• Key findings across seasons:
• Yields of tomato and green onion improved under partial shade.
• Lettuce grew more slowly under shade, thereby extending its season.
• Radishes showed no yield differences.
• Leafy greens yielded less, likely due to irrigation scheduling and inhomogeneity in irradiance.
• Sweet potato yields declined under full shade, yet in mixed-shade rows the crop performed unexpectedly well.
• Corn maintained biomass, but high heat drastically reduced pollination across all plots; shading reduced the daily maximum temperature by 0.5–1°C, offering limited heat-stress mitigation.

Ecosystems and Biodiversity

• Enhanced ground cover and habitat complexity compared with bare solar fields.
• A working prototype of a solar-plus-ecosystem configuration that challenges the “sterile solar field” assumption.

Educational and Institutional Impact

• The site now functions as a WEFE Nexus demonstration hub, hosting researchers, practitioners, delegations, and a course module.
  
  The system is operating as intended and has demonstrated clear technical viability and early WEFE co-benefits, but the project remains an ongoing research platform. Long-term data on productivity, water-use efficiency, ecosystem services, and system performance are still being collected. 

The project shows that integrating small-scale APV with off-grid irrigation in an arid environment is feasible but comes with notable challenges. Reliable operation depends on careful energy budgeting, strong awareness of seasonal variations in PV output, and the inherent limits of battery storage—demonstrating that off-grid systems require ongoing adjustment rather than “set-and-forget” operation. Crop performance differed by species and planting location, underscoring that APV does not guarantee yield improvements and that establishing vegetation under harsh desert conditions requires close management and continuous observation.

Several design elements—detached substrate beds, polyculture planting, and structured microclimate and soil–water monitoring—offer replicable tools for sites with poor soils or restricted ground disturbance. While the system components themselves are widely available, successful replication depends on local technical capacity, the willingness to maintain sensors and equipment, and the ability to troubleshoot off-grid energy fluctuations.

From a broader WEFE perspective, the project demonstrates that integrating food, water, and energy objectives is possible but not automatic; it requires coordinated planning, adaptive management, and clear operational routines.