ASHS 2025 Conference

With populations rising and cities expanding, it is necessary to consider new ways to supplement current energy and food systems. Urban agriculture has the potential to enhance food systems, energy production and stormwater management within urban areas. This can be achieved by implementing rooftop agrivoltaics (RAV), a combination of rooftops, agriculture, and photovoltaics. This study evaluates the growth and yield of leafy greens in RAV by examining how shade from photovoltaic arrays influences leafy green production. An RAV system was built at the CSU Spur Campus in Denver, Colorado, featuring a 45 cm deep substrate and three treatments: full sun, opaque silicon PV modules, and bifacial silicon PV modules. Leafy greens—arugula, kale, lettuce, spinach, and Swiss chard—were germinated and transplanted in randomized rows, with environmental conditions monitored continuously using HOBO sensors. Fresh weight, dry weight, stomatal conductance, and plant size at harvest were collected, and statistical analysis was conducted using two-way ANOVA to assess the effects of the treatments on each crop type. Leafy greens grown under the PV treatments had reduced stomatal conductance compared to the full sun treatment. The plant size at harvest was also higher in lettuce and spinach grown under the PV module treatments compared to the full sun. Fresh and dry weight of plants grown under the opaque and bifacial PV module treatments, however, were reduced compared to the full sun treatment. By understanding these interactions, the research aims to determine the feasibility of RAV systems for urban agriculture.