Tag Archive for: Biosphere

Biosphere 2 Agrivoltaic Learning Lab

Biosphere 2, located in Oracle, Arizona, houses one of the first agrivoltaic research sites in the United States. The site was built seven years ago with a 21.6-kW solar PV array shading a 9×18-meter garden. Greg Barron-Gafford, along with several graduate students, use this garden to study the changes in phenology of several varieties of vegetables and fruit, soil health, panel production, water consumption, and carbon scrubbing that are affected by the shading of the solar array. A control area of the same size with no shading was built within 10 feet of the solar garden for comparison. The fruits and vegetables grown here are tomatoes, caribe potatoes, butternut squash, red beans, bok choy, and basil.

Agrivoltaic solar garden at Biosphere 2. Photo: NCAT

Underneath the agrivoltaic solar PV array system. Photo: NCAT

Control garden at the Biosphere 2 agrivoltaic site. Photo: NCAT

Harvested food grown in the solar garden at Biosphere 2. Photo: Mariah Rogers, University of Arizona

Phenology, the study of the relationship between climate and plant life production and health, is a main focus at Biosphere 2. Graduate students are studying the timing of fruiting and/or flowering, along with plants’ dying cycle, at the solar garden and comparing these results to the full-sun control site. They are currently working with the National Phenology Network to share and analyze data. Soil health is also monitored by testing the amount of carbon in the soil. This is a slower process, as it takes time for carbon, microbes, and other organics to develop in dryland areas such as Arizona.

The students test the greenhouse gas consumption or carbon-scrubbing abilities of the plants as the conditions change. They track photosynthesis of the plants grown beneath the panels versus those grown in the control area to see when and for how long photosynthesis is affected by the hot climate and the shade. Plants’ ability to carbon scrub decreases in hot conditions, which in turn affects their health and growth patterns. This research is showing that plants can maximize their ability to carbon scrub under the solar panels due to the shading and reduced heat seen in dryland agriculture.

Rows of tomatoes and testing equipment at the solar garden. Photo: NCAT

The watering-treatment experiment tests the health and production of plants using two watering methods. Half of the plants are on a watering schedule based on what the plants in the control site need to flourish. The other half of test plants are watered half the time, therefore receiving half the water. Both watering schedules are used in the solar garden and control garden for comparison. These experiments are proving that shaded growing areas in dryland agriculture can use less irrigation water to grow crops if planted under a solar array.

The watering system at the Biosphere 2 solar garden. Photo: NCAT

Recently, these plants went through a blind taste test to see if there is any taste difference between the fruits and vegetables grown under solar versus under full sun. The main plants tested were tomatoes, beans, squash, and basil. Each plant group was harvested from both the control site and the solar site on the same day, washed the same, and presented the same. The study found that no significant taste difference was observed—good news for farmers worried about a change in flavor for their crops.

Sample preparation for the solar garden grown taste tests. Photo: Mariah Rogers, University of Arizona

The solar panel temperatures are being tested using thermocouples taped to the underside of the panels. Electricity flows easier in cooler conditions; thus, solar panels produce best when the underside of the panel stays under 75-80oF. The garden below creates a cooler environment for the panels than arrays with a gravel layout.

Thermocouples taped to the back of the solar PV panels. Photo: NCAT

Graduate students are also testing a remote sensing system at the solar site using satellite imaging and remote monitoring to learn whether remote sensors and monitoring are effective in site monitoring. This technology will hopefully help with site monitoring from a distance when travelling is not an option.

Greg Barron-Gafford and his team of graduate students are making leaps and bounds in agrivoltaic farming research. They hope to educate farmers across dryland agriculture and beyond on the double benefits of growing under solar panels while also producing electricity. To learn more about this program please watch the video below and visit Greg’s website. https://www.barrongafford.org/agrivoltaics.html

Follow the Sun Tour: Learning from Arizona’s Biosphere 2 and Manzo Elementary Agrivoltaics  

By Dr. Stacie Peterson

The interdisciplinary research at Biosphere 2 and Manzo Elementary School in Tucson, Arizona is foundational for agrivoltaics in the United States.  My first introduction to agrivoltaics came from research at these sites, in the article Agrivoltaics Provide Mutual Benefits Across the Food-Energy-Water Nexus in Drylands. The opportunity to tour these sites, meet the researchers, and provide the AgriSolar Clearinghouse network with a way to connect was exciting indeed.

The tour started at the Biosphere 2 site, where Dr. Greg Barron-Gafford and graduate students Kai Lepley, Alyssa Salazar, Nesrine Rouini, and Caleb Ortega described their research, findings, and future projects. Greg provided a background of Biosphere 2, research conducted at the site, its application to agrivoltaics throughout the country, and its correlation to work at the Manzo Agrivoltaic site.    

Kai Lepley and Nesrine Rousini then described their work employing classic plant physiological instruments and novel ground-based remote sensing tools for tracking plant phenology and growth.  Alyssa Salazar described her studies on agrivoltaics impacts to the phenology and growing season patterns of different crops across our growing seasons and how this research can help determine how this approach might extend the growing seasons of certain crops.  Caleb Ortega described his planting approach as well as efficient and creative ways of collecting data.  They then asked the tour to help plant seeds for next years’ agrivoltaic experiments.

After a tour of the Biosphere 2 complex, the group travelled to Manzo Elementary Agrivoltaic site, where Mariah Rogers, Mira Kaibara, Stacy Evans, and Dr. Andrea Gerlak led a lunch-and-learn about the food science, social science, citizen science, student activities, and agrivoltaic food programs.  Mariah’s research involves blind taste tests of agrivoltaic and traditionally grown crops to determine if there are detectable differences in preference.

Dr. Greg Barron-Gafford
Sewing seeds for 2022 research
On-site agrivoltaic research at Biosphere 2
Biosphere Agrivoltaic Research
Follow the Sun Tour’s first stop: Biosphere 2
Manzo Elementary’s agrivoltaic site
Manzo Elementary’s Mariah Rogers explaining agrivoltaic food science

Dr. Andrea Gerlak, professor of Public Policy at the University of Arizona with extensive experience working on water resource policy and management issues, described her research, and its correlation to work by Alexis Pascaris, and their collaboration on the USDA-NIFA grant for agrivoltaics research (SCAPES project). Alexis is a social scientist whose research involves engaging key stakeholders – including farmers and solar industry professionals – to understand their perspectives about opportunities and barriers to agrivoltaics, which helps inform policy innovation and identify pathways to advance dual-use development responsibly. 

We were lucky enough to be joined by Alexis Pascaris of AgriSolar Consulting, Thomas Hickey of Sandbox Solar, Gema Martinez of BayWa r.e., Brian Naughton of Circle Two and Sandia National Laboratories, Mark Peterson of the Montana Department of Environmental Quality, and AgriSolar Clearinghouse Partner Coordinator, Danielle Miska. In coming months, we will lead tours to Minnesota, Colorado, Oregon, California, Massachusetts, Idaho, New York, and Texas. We hope you’ll join us! 

NCAT’s AgriSolar Clearinghouse Launches National ‘Follow the Sun’ Tour

The AgriSolar Clearinghouse, developed by the National Center for Appropriate Technology (NCAT) is launching a series of hands-on field trips to see firsthand the benefits of co-locating sustainable agriculture and solar energy. The Follow the Sun Tour’s first stop is April 5 at Biosphere 2 in Oracle, Arizona.

“AgriSolar allows us to harvest the sun twice. As America’s appetite for sustainably grown products and renewable energy continues to increase, agrisolar has the potential to provide both resources,” says NCAT Energy Program Director Dr. Stacie Peterson. “The Follow the Sun Tour will visit agrivoltaic sites around the country that are seeing success with things like co-located grazing, habitat rehabilitation, crop production, and cutting-edge research. Our national network of partners includes the world’s leading agrivoltaic experts and we are excited to connect the public with partners like Dr. Greg Barron-Gafford and provide the opportunity to tour his research sites.”  

Join Peterson and leading agrivoltaic researcher Dr. Barron-Gafford on a tour of the agrisolar research underway at Biosphere 2. Biosphere 2 is the world’s largest controlled environment dedicated to understanding the impacts of climate change. Operated by the University of Arizona, the facility includes 3.14 acres, with 7.2 million cubic feet sealed underneath glass domes. Barron-Gafford and his team are investigating the potential for reintroducing vegetation into the typical PV power plant installation in drylands. His research shows that this approach may lead to increased renewable energy production, increased food production, and reduced water use. For interested participants, the tour will continue to the Manzo Elementary School Agrivoltaic site in Tucson.

Space is limited. RSVP is required.

NCAT created the nation’s first AgriSolar Clearinghouse to connect farmers, ranchers, land managers, solar developers, and researchers with trusted, practical information to increase the appropriate co-location of solar and agriculture. It’s funded by the U.S. Department of Energy. The AgriSolar Clearinghouse features a library of more than 400 peer-reviewed articles, a media hub featuring videos, podcasts, and relevant news, and a user forum to directly connect people interested in agrivoltaic development in real-time. Partner organizations include leading universities, the Smithsonian, sustainable agriculture and energy advocates, the Center for Rural Affairs, and the national energy laboratories.

The benefits of co-locating solar with appropriate agricultural land include producing food, conserving ecosystems, creating renewable energy, increasing pollinator habitat, and maximizing farm revenue.

The AgriSolar Clearinghouse’s free Follow the Sun Tour will stop at about a dozen agrivoltaic sites over the next two years. Future field trips will include visits to sites in Colorado, Massachusetts, Minnesota, Oregon, New York and more. Sign up for the AgriSolar Extra to be sure you know about upcoming Follow the Sun Tour stops.