Green energy meets urban agriculture: Unveiling the carbon reduction potential of Rooftop Agrivoltaics

Global warming and rapid population growth are intensifying land competition for energy and food production, threatening urban food and energy security due to high emissions associated with food transportation. The Rooftop Agrivoltaics (RAV) model integrates rooftop agriculture with photovoltaic energy generation, aiming to produce clean energy and culti-vate vegetables with 'zero food miles.' This study employs Geographic Information Systems (GIS), life cycle assessments, biogeochemical models, and solar energy simulations to rigor-ously assess RAV's potential for carbon reduction. Analyzing lettuce as a model crop in Fu-zhou, China, we found approximately 69.7 km² of viable space for RAV, with a potential to produce 8.875 × 10⁵ tons of lettuce annually—about 20% of the local vegetable production. This model could reduce carbon emissions from food transportation by 2.798 × 10⁵ t CO_2-eq annually and generate about 1850 GWh of solar power yearly, accounting for 0.74% of Fu-zhou's total electricity demand. Annually, RAV could reduce Fuzhou's carbon emissions by approximately 1.614 × 10⁶ t CO_2-eq, which translates to a reduction of about 2.68% of the city's total carbon emissions. RAV will cause 6.2 × 10⁶ t CO_2-eq emissions over a 30-year lifespan. However, its net carbon reduction over the lifespan will reach 3.242 × 10⁷ t CO_2-eq. Furthermore, in scenarios of electric grid transformation and urban expansion, RAV's potential electricity generation by 2030 is expected to increase to between 1916 GWh and 1987 GWh. In conclusion, RAV has significant carbon reduction potential and can play a role in future urban planning to contribute to addressing global climate change.