Dr. Gary Paul Nabhan, Kellogg Endowed Chair in Desert Food and Water Security, University of Arizona, visited FAFS (November 5) to deliver the lecture: Agrivoltaic innovations: Co-locating food production and solar renewable energy - How to maximize desert crop yields, water savings, and energy generation. The vulnerabilities of our food, energy, and water systems to projected, increasingly stressful, climatic change make building resilience in renewable energy and food production a fundamental challenge.
Dr. Nabhan discussed how he and his team have investigated a novel approach to solve this problem by creating a hybrid of co-located agriculture and solar photovoltaic (PV) infrastructure to maximize agricultural production and improve renewable energy production, all while reducing demand for irrigative waters. They took an integrative approach - monitoring microclimatic conditions, PV panel temperature, soil moisture and irrigation water use, plant ecophysiological function, and plant biomass production within this novel “agrivoltaics” ecosystem and in traditional PV installations and agricultural settings (control plots) to quantify tradeoffs associated with this system. They found that shading by the PV panels provides multiple additive and synergistic benefits. In terms of water, levels of soil moisture remained higher after each irrigation event within the soils under the agrivoltaics installation than the traditional agricultural setting, indicating that less irrigation was required to maintain adequate moisture conditions. As a result, they found reduced drought stresses on photosynthetic capacity and water use efficiency and greater food production in the agrivoltaic installation relative to the control plants. Combined with localized cooling of the PV panels resulting from the transpiration from the vegetative “understory”, which reduces heat stress on the panels and boosts their performance, Dr. Nabhan and his team also discovered a win-win-win at the food-water-energy nexus. The findings presented provide a foundation and motivation for future explorations towards resilience of food and energy systems under the future projected increased environmental stress involving heat and drought.
Dr. Nabhan concluded his talk by highlighting the role of agrivoltaics in the WEFRAH initiative. Agrivoltaics can be integrated under WEFRAH by creating an outdoor STEM teaching lab at AREC. Agriculture, engineering, nutrition and health sciences students can engage in the design of PV array, select and compare the yields of culinary herbs and food crops, and measure harvesters’ heat stress symptoms in a time when food security is a challenge.
Dr. Nabhan delivered a second lecture (November 13) on Climate change effects on food safety and food waste: Reducing impacts in Lebanon and other arid zones. Dr. Nabhan reviewed the emerging threats, which are heightened by climate change, of microbial activities in producing meats and vegetables, preparing and offering them in open-air restaurants, and disposing of contaminated food waste. He discussed the importance of adopting an integrated farm-to-table approach that includes from water source and field, to harvesting area, storage sites, and handling areas in kitchens, in order to reduce impacts and divert food waste from sanitary landfills for compost and other uses in Lebanon and arid zones. This approach is consistent with AUB’s Knowledge-to-Policy Briefing Note on “the need for an effective food safety system” to protect consumers in Lebanon; it is also consistent with the Sustainable Agriculture Coalition’s recently-published agro-ecological “co-management” strategy that responds to site-specific conditions and integrates cultural, biological, and mechanical practices to promote food safety and reduce, divert, and convert food waste into safe organic amendments that promote soil health.
His presentation also featured commentaries by Dr. Issmat Kassem, Assistant Professor of Food Microbiology (FAFS-AUB), who highlighted food safety issues in Lebanon. Dr. Nabhan presented an award-winning 8-minute documentary “Man in the Maze” about reducing food waste and creating soil health to augment food security in the deserts of the Americas. The video shows that binational food supply chains increase food spoilage risk and food waste through “dumping” unsold produce and vegetables in landfills at the US/Mexico border. The film won the best short science film documentary at the Sundance Film Festival, attracting a million views and several funders.